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1.
Pulmonology ; 29 Suppl 4: S80-S85, 2023 Dec.
Article in English | MEDLINE | ID: mdl-34219041

ABSTRACT

INTRODUCTION AND OBJECTIVES: Subjects with severe acquired brain injury (sABI) require long-term mechanical ventilation and, as a consequence, the tracheostomy tube stays in place for a long time. In this observational study, we investigated to what extent the identification of late tracheostomy complications by flexible bronchoscopy (FBS) might guide clinicians in the treatment of tracheal lesions throughout the weaning process and lead to successful decannulation. SUBJECTS AND METHODS: One hundred and ninety-four subjects with sABI admitted to our rehabilitation unit were enrolled in the study. All subjects received FBS and tracheal lesions were treated either by choosing a more suitable tracheostomy tube, or by laser therapy, or by steroid therapy, or by a combination of the above treatments. RESULTS: Overall, 122 subjects (63%) were decannulated successfully. Our subjects received 495 FBSs (2.55 per subject) and as many as 270 late tracheostomy complications were identified. At least one complication was found in 160 subjects (82%). In only 11 subjects, late tracheostomy complications did not respond to the treatment and were the cause of decannulation failure. CONCLUSIONS: In conclusion, in sABI patients FBS is able to guide successful tracheostomy weaning in the presence of late tracheostomy complications that could get in the way decannulation.


Subject(s)
Brain Injuries , Tracheostomy , Humans , Bronchoscopy , Device Removal , Respiration, Artificial , Postoperative Complications , Brain Injuries/rehabilitation
2.
J Endocrinol Invest ; 41(7): 831-837, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29288439

ABSTRACT

PURPOSE: Hyperhomocysteinemia is a known cardiovascular risk factor and a key player in the inflammatory activation of autoimmune diseases. Hashimoto's thyroiditis (HT) is the leading cause of hypothyroidism which, in itself, has been associated with a significant raise of homocysteine (Hcy) levels and increased cardiovascular risk. Our aim was to assess the impact of HT on Hcy levels in patients with acute hypothyroidism. METHODS: We prospectively enrolled 121 patients (mean age: 46 years, F/M = 102/19) with acute post-surgical hypothyroidism. Based on the presence of anti-thyroid antibodies and the histological description of an inflammatory infiltrate, 26 and 95 patients were classified as HT and non-HT, respectively. Several parameters including thyroid-stimulating hormone (TSH), levels of serum free T3 and free T4, weight, glucose levels, total cholesterol, creatinine, vitamin B12, ferritin and erythrocyte sedimentation rate were obtained from all patients and correlated with Hcy levels. RESULTS: Median Hcy level in the whole cohort was 16.8 µmol/L (normal values: < 12 µmol/l). Among all parameters analysed, only Hcy levels were significantly different between HT and non-HT patients (median Hcy = 19.7 vs 16.2 µmol/L, respectively; p = 0.018, Mann-Whitney U test). Analysis of covariance showed the presence of HT to be the strongest predictor of Hcy levels (coefficient = 0.25534, p = 0.001). Serum TSH was not significantly associated with Hcy levels (p = 0.943). CONCLUSION: In patients with iatrogenic hypothyroidism, those with HT have significantly higher Hcy levels than those without HT. The increase of Hcy levels appears to be mainly determined by the HT-related immune-inflammatory condition.


Subject(s)
Autoimmunity , Hyperhomocysteinemia/etiology , Hypothyroidism/complications , Thyroid Gland/immunology , Acute Disease , Adult , Female , Hashimoto Disease/complications , Hashimoto Disease/epidemiology , Hashimoto Disease/immunology , Hashimoto Disease/surgery , Humans , Hyperhomocysteinemia/epidemiology , Hyperhomocysteinemia/immunology , Hypothyroidism/epidemiology , Hypothyroidism/immunology , Iatrogenic Disease/epidemiology , Iodine Radioisotopes/therapeutic use , Male , Middle Aged , Risk Factors , Thyroid Gland/radiation effects
3.
Radiat Prot Dosimetry ; 129(1-3): 119-22, 2008.
Article in English | MEDLINE | ID: mdl-18487616

ABSTRACT

Recent advances in semiconductor pixel detectors and read-out electronics allowed to build the first prototypes of single photon-counting imaging systems that represent the last frontier of digital radiography. Among the advantages with respect to commercially available digital imaging systems, there are direct conversion of photon energy into electrical charge and the effective rejection of electronic noise by means of a thresholding process. These features allow the photon-counting systems to achieve high imaging performances in terms of spatial and contrast resolution. Moreover, the now available deep integration techniques allow the reduction of the pixel size and the improvement of the functionality of the single cell and the read-out speed so as to cope with the high fluxes found in diagnostic radiology. In particular, the single photon-counting system presented in this paper is based on a 300-microm thick silicon pixel detector bump-bonded to the Medipix2 read-out chip to form an assembly of 256 x 256 square pixels at a pitch of 55 microm. Each cell comprises a low-noise preamplifier, two pulse height discriminators and a 14-bit counter. The maximum counting rate per pixel is 1 MHz. The chip can operate in two modalities: it records the events with energy above a threshold (single mode) or between two energy thresholds (window mode). Exploiting this latter feature, a possible application of such a system as a fast spectrometer is presented to study the energy spectrum of diagnostic beams produced by X-ray tubes.


Subject(s)
Diagnostic Imaging , Image Enhancement/methods , Image Processing, Computer-Assisted/instrumentation , Image Processing, Computer-Assisted/methods , Photons , Tomography, X-Ray Computed/methods , Humans , Image Enhancement/instrumentation , Radiographic Image Enhancement/instrumentation , Radiographic Image Enhancement/methods , Radiometry , Tomography, X-Ray Computed/instrumentation
4.
Radiat Prot Dosimetry ; 129(1-3): 227-30, 2008.
Article in English | MEDLINE | ID: mdl-18375463

ABSTRACT

The work presented here was developed in the framework of the SENTINEL Project and is devoted to the analysis of dental radiology dosimetric data. The procedure of data processing allows the analysis of some important aspects related to the protection of the patient and the staff because of the position of the operators near the patient and their exposure to the radiation scattered by the patient. Dental radiology data was collected in an Italian hospital. Following the Italian quality assurance (QA) protocols and suggestions by the leaders of the SENTINEL Project, X-ray equipment performances have been analysed in terms of: kVp accuracy, exposure time accuracy and precision, tube output, dose reproducibility and linearity, beam collimation, artefacts and light tightness. Referring to these parameters the physical quality index (QI) was analysed. In a single numerical value between 0 and 1, QI summarises the results of quality tests for radiological devices. The actual impact of such a figure (as suggested by international QA protocols or as adopted by local QA routine) on the policy of machine maintenance and replacement is discussed.


Subject(s)
Diagnostic Imaging/instrumentation , Diagnostic Imaging/standards , Radiation Protection/standards , Radiography, Dental/methods , Radiology Department, Hospital/standards , Radiometry/methods , Humans , Quality Assurance, Health Care , Quality Control , Radiography, Dental/instrumentation , Radiometry/standards
5.
In Vivo ; 19(6): 1071-6, 2005.
Article in English | MEDLINE | ID: mdl-16277024

ABSTRACT

In human blood, breakdown of gastrin-releasing peptide and other bombesin-related peptides occurs in less than 15 min. This quick enzymatic cleavage might impair the diagnostic use of labelled bombesin (BN). 99mTc-labelled bombesin (99mTc BN1) was injected intravenously and dynamic uptake data were acquired for diagnosing 26 cancers of different origin: 15 breast, 3 prostate, 5 colo-rectal, 1 pancreas, 2 small cell lung cancers and 1 gastrinoma. Background subtracted tumour uptake data were plotted against time and fitted with known mathematical functions. Twenty-three out of 26 cancers showed rapid increase of radioactivity followed by a radioactivity plateau, with some oscillations around the average plateau value. The time to 80% of max activity (T80) was the reference parameter to measure and to compare the uptake speeds. The slowest T80 was 7 min in one T1b breast cancer, gastrinoma reached T80 in 5 min and node-positive prostate cancers in 2 min. N+ breast cancers showed T80 at 3.62 +/- 0.75 min, N- breast cancers at 5.5 +/- 0.88 min (p < 0.02). When all the tumours were considered, N+ tumours showed T80 at 2.68 +/- 1.03 min and N- cancers at 5.5 +/- 0.82 min. In all the cancer types, the uptake of 99mTc BN was faster than 10 min. This result shows the ability of 99mTc BN to image tumours. The faster uptake by N+ versus N- cancers probably depends on the higher blood flow in N+ cancers.


Subject(s)
Bombesin/analogs & derivatives , Neoplasms/diagnostic imaging , Neoplasms/metabolism , Organotechnetium Compounds , Breast Neoplasms/blood supply , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/metabolism , Carcinoma, Small Cell/blood supply , Carcinoma, Small Cell/diagnostic imaging , Carcinoma, Small Cell/metabolism , Colonic Neoplasms/blood supply , Colonic Neoplasms/diagnostic imaging , Colonic Neoplasms/metabolism , Female , Gastrinoma/blood supply , Gastrinoma/diagnostic imaging , Gastrinoma/metabolism , Humans , Kinetics , Lung Neoplasms/blood supply , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/metabolism , Male , Neoplasm Staging , Neoplasms/blood supply , Pancreatic Neoplasms/blood supply , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/metabolism , Prostatic Neoplasms/blood supply , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/metabolism , Radionuclide Imaging , Radiopharmaceuticals , Receptors, Bombesin/metabolism , Rectal Neoplasms/blood supply , Rectal Neoplasms/diagnostic imaging , Rectal Neoplasms/metabolism , Regional Blood Flow
6.
Epilepsia ; 41(11): 1485-8, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11077464

ABSTRACT

PURPOSE: Antiepileptic drugs are known to exacerbate absence and myoclonic seizures, especially in patients with idiopathic generalized epilepsies. Exacerbation of nonconvulsive generalized seizures in patients with partial epilepsy is less common. Recently, however, a number of cases of putative generalized nonconvulsive status epilepticus (NCSE) or NCSE without further specification have been reported in patients with chronic partial epilepsy treated with the gamma-aminobutyric acid reuptake inhibitor tiagabine. Although complex partial status epilepticus during tiagabine therapy has also been reported, possible precipitation of NCSE specifically associated with frontal lobe discharges does not appear to have been recognized. In this communication, we describe the case of a boy with familial bilateral perisylvian polymicrogyria who developed frontal NCSE after being stabilized on high-dose tiagabine METHODS: A 12-year-old boy with familial bilateral perisylvian polymicrogyria, mental retardation, and refractory partial seizures was administered tiagabine in addition to sodium valproate. The tiagabine dosage was increased gradually up to 10 mg t.i.d. (1 mg/kg per day), resulting in complete seizure control. RESULTS: After 1 week on maintenance treatment, seizures were completely controlled, but the child developed hypoactivity, decreased reactivity, and affective detachment. An EEG recording revealed subcontinuous sharp-wave discharges with irregular runs of atypical spike-wave complexes over the anterior regions of both hemispheres, consistent with a diagnosis of frontal NCSE. A reduction in tiagabine dosage to 15 mg/day led to complete regression of the behavioral and affective changes and to disappearance of the subcontinuous EEG discharges. CONCLUSIONS: Although tiagabine-induced NCSE has been described previously, particularly in patients with preexisting spike-wave abnormalities, this is the first report that identifies its potential role in the precipitation of frontal NCSE.


Subject(s)
Anticonvulsants/adverse effects , Brain/abnormalities , Epilepsies, Partial/drug therapy , Epilepsy, Frontal Lobe/chemically induced , Nipecotic Acids/adverse effects , Status Epilepticus/chemically induced , Anticonvulsants/therapeutic use , Child , Dose-Response Relationship, Drug , Drug Administration Schedule , Electroencephalography/statistics & numerical data , Epilepsy, Frontal Lobe/diagnosis , Humans , Male , Nipecotic Acids/therapeutic use , Status Epilepticus/diagnosis , Tiagabine
7.
J Child Neurol ; 15(9): 622-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11019794

ABSTRACT

A 17-year-old boy with polymorphic simple and complex partial seizures is described. Magnetic resonance imaging revealed a unilateral periventricular nodular heterotopia near the occipital ventricular right horn. Interictal and ictal electroencephalographic recordings showed bilateral specific epileptiform anomalies in the occipital region and asynchronous slow waves in frontal areas. Single photon emission computed tomography documented a reduction in regional cerebral blood flow in an area of the left occipital cortex and a symmetric increase in tracer uptake in the frontal lobes. The neuropsychologic assessment revealed a dysfunction of the frontal associative areas. Data collected led the authors to suspect a more diffuse cortical dysfunction than the nodular heterotopia revealed on magnetic resonance imaging.


Subject(s)
Cerebral Ventricles/pathology , Choristoma/pathology , Epilepsies, Partial/diagnosis , Occipital Lobe/physiopathology , Adolescent , Brain Diseases , Electroencephalography , Humans , Magnetic Resonance Imaging , Male , Occipital Lobe/blood supply , Tomography, Emission-Computed, Single-Photon
8.
Radiol Med ; 99(5): 368-73, 2000 May.
Article in Italian | MEDLINE | ID: mdl-10938706

ABSTRACT

INTRODUCTION: The method recommended by Report no. 34 (1982) of the International Commission on Radiological Protection (ICRP) for patient dose computation in diagnostic radiology is based on tabulated dosimetric data obtained from Monte Carlo simulations on anthropomorphic phantoms described by simple mathematical functions. When computing the dose absorbed by an adult patient, this method suffers from two main limitations: first, the geometrical parameters--and in particular focus-to-film distance and film size--are fixed, which makes the dosimetric data of limited use when the examination geometry differs from the ICRP standard. In addition, when patient size and mass differ considerably from the corresponding quantities of the mathematically described phantom (the so-called reference man, with a height of 174 cm and a mass of 70.9 kg) the ICRP method may lead to great errors in dose estimate. The aim of the present paper is to indicate a method to overcome the above limitations. MATERIAL AND METHODS: The algorithm proposed in this work is based on the method suggested by Huda and Gkanatsios in order to compute the effective dose through a linear first of the energy imparted per unit dose-area product as a function of the half value thickness and by using fit coefficients depending on both phantom thickness and peak voltage. We devised a procedure to normalize the dose computed with this methods with respect to the equivalent effective dose obtained with the ICRP method. We therefore determined the dependence of the absorbed dose on focus-to-film distance, film size and patient anatomy. RESULT AND DISCUSSION: We found that--for each value of patient mass--the dose dependence on film size can be approximated by a polynomial function, while the dose dependence on focus-to-film distance can be approximated by a power law. If the above parameters vary in a limited range close to the ICRP standard, a linear fit can be performed without introducing a considerable error. The linear fit coefficients, on the other hand, were found to depend on the average body surface, a parameter which takes into account both patient height and mass. Thus, determining the normalization factor for each projection and each view allows to estimate the absorbed dose under different geometrical conditions. The method has been verified by considering four of the most common X-ray procedures (chest AP, cervical spine LAT, lumbar spine AP and head LAT). CONCLUSIONS: The average error on dose estimation is about 13%. In the very next future the method will be extended to all the projections and views of ICRP Report no. 34, and we plan to integrate the described algorithm in a computer program devoted to the automatic computation of patient dose.


Subject(s)
Algorithms , Monte Carlo Method , Radiometry/methods , Adult , Body Height , Body Mass Index , Humans , Radiation Dosage , Radiation Protection/standards
9.
J Nucl Med ; 41(4): 647-54, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10768566

ABSTRACT

UNLABELLED: This study evaluates the short- and long-term therapeutic efficacy of 186Re-1,1-hydroxyethylidene diphosphonate (HEDP) in the palliation of painful bone metastases and the influence of variables before therapy in determining the characteristics of pain palliation. METHODS: Sixty patients with painful bone metastases from different tumor types were treated with 1406 MBq 186Re-HEDP. After treatment, the patients were followed up clinically at weekly intervals for the first month and monthly thereafter up to 1 y, until death or pain relapse. Pain response was graded as complete, partial, minimal, or absent using the Wisconsin test scoring system. Duration of pain relief, performance status, tumor markers, serum alkaline phosphatase levels, hematologic toxicity, and metastatic bone progression were also evaluated. RESULTS: Overall, 80% of individuals experienced prompt relief of pain, with 31% complete, 34% partial, and 15% minimal responses. Transient World Health Organization grade 1-2 hematologic toxicity was apparent, with a decrease in the mean platelet (32%) and mean leukocyte (18%) counts at 3 and 4 wk, respectively. The degree of pain response did not correlate with any pretreatment variable. The duration of pain relief ranged from 3 wk to 12 mo and correlated positively with the degree of response (P = 0.02) and negatively with pretreatment scintigraphic scores and alkaline phosphatase levels (P = 0.02). CONCLUSION: 186Re-HEDP is effective for fast palliation of painful bone metastases from various tumors. The effect tends to last longer if patients are treated early in the course of their disease.


Subject(s)
Bone Neoplasms/radiotherapy , Bone Neoplasms/secondary , Etidronic Acid/therapeutic use , Organometallic Compounds/therapeutic use , Pain, Intractable/radiotherapy , Palliative Care , Radioisotopes/therapeutic use , Aged , Bone Neoplasms/diagnostic imaging , Breast Neoplasms/physiopathology , Female , Follow-Up Studies , Humans , Male , Prostatic Neoplasms/physiopathology , Radionuclide Imaging , Time Factors
10.
Radiol Med ; 100(5): 372-7, 2000 Nov.
Article in Italian | MEDLINE | ID: mdl-11213418

ABSTRACT

INTRODUCTION: The evaluation of the quality of a radiological device depends on both clinical judgement about diagnostic imaging and physical judgement about technical performance. The latter is the final result of a set of measurements of several physical quantities. The aim of the present paper is to make a synthesis of such measurements through a parameter whose comparison with a threshold value would allow to establish whether a given radiological machine is acceptable from the point of view of physical quality. MATERIAL AND METHODS: The parameter, which we called quality index, was obtained by considering, for each operating condition, the values of physical quantities which exceed their limits and by giving them a different weight, depending on their influence on image quality, patient dose, or both. Further analysis led to assign a gravity index to such quantities as a function of the extent of the discrepancies with respect to their limits. RESULTS AND DISCUSSION: The method was illustrated through the example of a simple radiological equipment with two separate hypothetical cases corresponding to different degrees of fault gravity. The method gave very different values of quality index, according to the extent of discrepancies found in the two cases. We gave suggestions about the way to follow in order to determine a proper threshold value for each kind of equipment. The invariance of the method with respect to the choice of the physical quantities and their limits was also shown. CONCLUSIONS: The proposed method appears to be useful because it makes a synthesis, through a single parameter, of a series of measurements of several physical quantities and allows to discriminate, through direct comparison with a threshold value, about the physical quality of a radiological device; in addition, it may be easily implemented into programs for the automated analysis of quality controls. The quality index may contribute, together with some other parameters to be defined in a forthcoming paper, in establishing a quantitative criterion in order to define equipment replacement priorities within the context of the technological improvement requested by the laws currently in force.


Subject(s)
Tomography Scanners, X-Ray Computed/statistics & numerical data , Tomography Scanners, X-Ray Computed/standards , Humans , Mathematical Computing
11.
Eur J Nucl Med ; 26(8): 824-9, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10436194

ABSTRACT

This study evaluated changes in lymphocyte subsets in patients with thyroid carcinoma who received iodine-131 for diagnostic and therapeutic purposes. Twenty thyroid cancer patients were entered in the study after total thyroidectomy: ten patients (group A) underwent whole-body scintigraphy with 185 MBq of (131)I and the other ten (group B) received 3700 MBq of (131)I therapy. All patients were in a hypothyroid state at the time of administration of (131)I and started L-thyroxine 150 microg/day 3 days after (131)I administration. Free and bound triiodothyronine and thyroxine, thyroid-stimulating hormone, thyroglobulin, thyroglobulin antibodies, thyroid peroxidase/microsomal antibodies, white blood cell, lymphocyte counts and lymphocyte subsets were serially determined at baseline and at days 2, 7, 15, 30 and 60 after (131)I administration. Twenty healthy age- and sex-matched individuals were used as a reference population for lymphocyte subset values. In group A only a reduction in NK cells at days 7 (P=0.043) and 15 (P=0.037) was observed. In group B, patients showed a delayed reduction in the total lymphocyte count at days 15, 30 and 60 (P=0.008, 0.004 and 0. 018, respectively), and a decrease in B cells throughout the study (at days 7, 15, 30 and 60: P=0.006, 0.0017, 0.0017 and 0.0017 respectively). A transient decrease in NK cells was observed at days 15 (P=0.025) and 30 (P=0.008). Among T cells, the helper phenotype (CD4+) was mainly affected, resulting in a reduction in the CD4+/CD8+ ratio at day 60 (P=0.046). Comparing the two groups, the numbers of B lymphocytes at day 30 (P=0.023) and NK cells at days 2 (P=0.037) and 30 (P=0.023) were significantly lower in group B. Neither group showed any clinical sign of immunosuppression during the follow-up period. In patients with thyroid cancer the sensitivity of lymphocytes to the effects of (131)I administered for diagnostic or therapeutic purposes depends upon lymphocyte phenotype and (131)I activity. NK cells are the most radiosensitive cells, being reduced even by low (131)I activity. At higher activity all subtypes show a reduction, which is more marked and prolonged for B lymphocytes and, to a lesser extent, for T-helper lymphocytes. These changes do not result in clinically relevant immunosuppression.


Subject(s)
Adenocarcinoma, Follicular/blood , Carcinoma, Papillary/blood , Iodine Radioisotopes/therapeutic use , Lymphocyte Subsets/radiation effects , Thyroid Neoplasms/blood , Adenocarcinoma, Follicular/diagnostic imaging , Adenocarcinoma, Follicular/radiotherapy , Adult , Carcinoma, Papillary/diagnostic imaging , Carcinoma, Papillary/radiotherapy , Case-Control Studies , Female , Humans , Lymphocyte Count/radiation effects , Male , Radionuclide Imaging , Thyroid Neoplasms/diagnostic imaging , Thyroid Neoplasms/radiotherapy , Time Factors
12.
Nucl Med Commun ; 20(8): 719-26, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10451880

ABSTRACT

Marked changes in cardiac function have been noted in patients with hyperthyroidism or hypothyroidism due both to changes in sympathetic system function and to biochemical modifications of myocardial tissue. Metaiodobenzylguanidine (MIBG), an analogue of norepinephrine, can be used to evaluate myocardial sympathetic tone. Here, we report myocardial 123I-MIBG kinetics in patients with differentiated thyroid carcinoma undergoing acute hypothyroidism followed by hormonal replacement as part of their routine clinical follow-up. Ten patients with differentiated thyroid carcinoma in acute hypothyroidism (A) and on hormonal replacement with thyroxine (150 micrograms.day-1) and triiodothyronine (20 micrograms.day-1) (B) underwent scintigraphic imaging 20 min and 4 h after injection of 111 MBq of ultra-high specific activity 123I-MIBG. No patient had cardiac disease or was taking medications that could interfere with cardiac or autonomic system function. Cardiac MIBG kinetics (heart-to-mediastinum, H/M, ratio and myocardial washout rate), serum norepinephrine, T3, T4, FT3, FT4, TSH, CPK, CPK-MB, blood pressure and ECG were evaluated. Systolic and diastolic blood pressure did not differ significantly between state A and state B. In the acute hypothyroid state (A), the prevalence of non-specific ST-T abnormalities was 70% and heart rate was significantly different (P < 0.001) than in state B. Norepinephrine and CPK-MB levels were higher during hypothyroidism, but this did not reach statistical significance. A positive correlation between early H/M and delayed H/M in the hypothyroid state (r = 0.57) and an even higher positive correlation between early H/M and delayed H/M in the euthyroid state (r = 0.91) were seen. The myocardial and mediastinal MIBG washout rates were significantly different between the hypothyroid and euthyroid states (P < 0.05), whereas the lung washout rate did not differ significantly between the two metabolic states. We conclude that the myocardial washout rate during hypothyroidism is clearly increased (P < 0.005) with a subclinical derangement of myocardial adrenergic innervation, which is rapidly reversed with hormonal therapy.


Subject(s)
3-Iodobenzylguanidine , Heart/diagnostic imaging , Hypothyroidism/complications , Hypothyroidism/diagnostic imaging , Radiopharmaceuticals , Thyroid Neoplasms/complications , Thyroid Neoplasms/diagnostic imaging , Adult , Aged , Female , Heart/physiopathology , Humans , Hypothyroidism/drug therapy , Kinetics , Male , Middle Aged , Norepinephrine/physiology , Radionuclide Imaging , Thyroid Neoplasms/pathology , Thyroxine/therapeutic use , Triiodothyronine/therapeutic use
13.
Radiol Med ; 97(4): 286-95, 1999 Apr.
Article in Italian | MEDLINE | ID: mdl-10414263

ABSTRACT

INTRODUCTION: Radiation exposure to the radiotherapy staff operating with linear accelerators comes from both normal exposure, which can be easily quantified by direct measurement, and potential exposure, whose evaluation is made difficult by its stochastic character. International guidelines recommend that risk be of the same order of magnitude for both types of exposure. We evaluated the health risk associated with potential exposure following the fault-tree approach suggested by the International Commission on Radiological Protection (IRCP) in its Publication 76. MATERIAL AND METHODS: Considering a typical radiotherapy installation we identified four possible staff irradiation scenarios, namely: 1) entry into the treatment room after a high-energy photon beam treatment, when induced radioactivity from photonuclear reactions has not decayed; 2) unintentional entry into the treatment room when the radiation beam is on; 3) beam failing to turn off at the end of treatment, and subsequent entry into the treatment room; 4) treatment room door inadvertently left ajar, and subsequent entry when the radiation beam is on. Each scenario depends on a particular set of parameters which are related to failure probabilities and workload. Average absorbed dose, exposure probability and related risk have been evaluated for each scenario. RESULTS: Under standard parameter set-up, the overall risk did not exceed the IRCP threshold (i.e., .0002) by more than four orders of magnitude. Two main sources of potential exposure have been identified, that is early entry into the treatment room before safe decay of activation products and unintentional entry during treatment. By varying the parameters within reasonable ranges, risk has been shown to correlate with personnel training, workload, installation characteristics and operational procedures. To optimize protection, quantitative limitations have been set for human error probability, daily workload, number and quality of safety devices and waiting time before entry after a treatment with high-energy radiations. CONCLUSIONS: Although the potential exposure risk for a typical radiotherapy department with standard safety devices is well below international recommended values, our results indicate that risk can be further decreased by improving personnel training, in particular relative to minimum time to entry after a high-energy treatment, to respecting warning signs and being skilled in emergency procedures. In addition, failing to install some safety devices or removing them after a failure may result in rapidly exceeding IRCP thresholds.


Subject(s)
Occupational Exposure , Particle Accelerators , Radiotherapy , Humans , Radiation Protection , Risk Assessment
14.
J Nucl Med ; 40(1): 46-51, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9935055

ABSTRACT

UNLABELLED: This study reports on a prototype single-photon emission mammograph (SPEM) dedicated to 99mTc-hexakis-2-methoxyisobutile isonitrile (MIBI) scintimammography. Main technical features are reported together with physical performance. Preliminary patient data are also reported. METHODS: The SPEM detector head is composed of a CsI(T1) scintillating array coupled to a Hamamatsu R3292 position-sensitive photomultiplier tube with crossed-wire anode. The high-resolution collimator is 35-mm thick with a 1.7-mm hole diameter and a 0.2-mm septal thickness. The electronic acquisition system is composed of five integrated cards with computation based on high-speed programmable microprocessors. The readout electronics include correction maps for on-line energy correction and spatial uniformity. The small size of the detector head allows the use of mechanical breast compression to minimize detection distance and tissue scatter. After physical SPEM performance evaluation in vivo scintimammography was performed in 29 patients and was compared with a state-of-the-art Anger camera. RESULTS: The SPEM showed an intrinsic spatial resolution of 2 mm, an energy resolution of 23% FWHM at 122 keV and spatial uniformities of 18% (integral) and 13.5% (differential). The SPEM imaged one 0.4-cm carcinoma missed by the Anger camera and resolved as separate lumps an irregular focal uptake on the Anger camera image. The remaining cases yielded concordant results. CONCLUSION: The SPEM prototype presented in this study shows adequate physical characteristics for 99mTc-MIBI scintimammography.


Subject(s)
Breast/diagnostic imaging , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-Photon/instrumentation , Adult , Aged , Breast Neoplasms/diagnostic imaging , Female , Gamma Cameras , Humans , Middle Aged
15.
Nucl Med Commun ; 20(12): 1113-21, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10664992

ABSTRACT

We evaluated the diagnostic yield of 99Tcm-MIBI scintimammography in a relatively large series of consecutive patients referred for breast surgery on the basis of physical examination or mammogram. 99Tcm-MIBI uptake was correlated to tumour size, receptor status, neovascularity, proliferating activity, P-170 glycoprotein expression and the patient's gonadal state. Three hundred consecutive patients referred to our institution, with either a positive mammogram or a palpable mass, were entered into the study. All patients underwent 99Tcm-MIBI scintimammography. Pathological status was obtained after surgery in all patients. Breast cancer was diagnosed in 218 (73%) patients. The MIBI scan was positive in 89% (194/218) cancer patients and in 17% (14/82) of patients with benign masses (false-positives); the scan was negative in 24 (11%) cancer patients (false-negatives). The sensitivity of MIBI scintigraphy was higher for tumours > 1 cm (95 vs 48% in lesions < or = 1 cm) and in pre-menopausal women (95 vs 85%). Conversely, the specificity was better for lesions < 1 cm (100%) and in post-menopausal women (89%). The positive predictive value of MIBI scan was good both in small (< 1 cm) and large tumours (100% and 93%, respectively) and slightly modified by gonadal state (89% and 96% in pre- and post-menopausal state). The negative predictive value was unsatisfactory, especially in small tumours and in older patients. The diagnostic performance increased stratifying data for tumour size, indicating that lesion size is a major determinant in the diagnostic accuracy of MIBI scintimammography. We conclude that 99Tcm-MIBI scintimammography is useful in the diagnostic evaluation of young patients, because it can select patients for further invasive diagnostic procedures. In older patients, a positive 99Tcm-MIBI scan is highly suggestive of malignancy and might be an indication for surgery. In the case of a negative scan, biopsy is advisable given the poor negative predictive value. Small tumour size and a well-differentiated histotype characterize false-negative cases.


Subject(s)
Breast Neoplasms/diagnostic imaging , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Adult , Aged , Breast Neoplasms/pathology , Breast Neoplasms/surgery , False Negative Reactions , False Positive Reactions , Female , Humans , Mammography , Middle Aged , Neovascularization, Pathologic/pathology , Postmenopause , Premenopause , Proliferating Cell Nuclear Antigen/analysis , Radionuclide Imaging , Radiopharmaceuticals/pharmacokinetics , Receptor, ErbB-2/analysis , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Reproducibility of Results , Technetium Tc 99m Sestamibi/pharmacokinetics
16.
Clin Ter ; 149(921): 43-7, 1998.
Article in English | MEDLINE | ID: mdl-9621488

ABSTRACT

PURPOSE: Strontium-89 is currently used for the treatment of painful bone metastases. This study reports on two preliminary experiences with low-dose platinum compounds, carboplatin and cisplatin, as radiosensitizers in 89Sr therapy. PATIENTS AND METHODS: 30 patients entered the carboplatin study: 15 patients (Group A) were treated with 148 MBq 89Sr followed by carboplatin (100 mg/m2 at 7 and 21 days) and 15 patients (Group B) were treated with 89Sr alone. 12 patients entered the cisplatin study: six patients (Arm 1) received 148 Mq 89Sr plus cisplatin (50 mg/m2) in two administrations (immediately before and 10 days after 89Sr injection) and six patients (Arm 2) received 89Sr plus two placebo administrations. Pain response was assessed 8 weeks after the therapy on the Wisconsin score modifications. RESULTS: No clinically significant adverse effects or myelosuppression by platinum compounds were observed. In carboplatin study a pain response was observed in 20 of 27 (74%) evaluable patients, 13/15 in group A and 7/12 in group B. The pain response in the patients treated with 89Sr and carboplatin was clearly superior to that seen in the patients treated with 89Sr alone (P = 0.025), whereas survival was only marginally better in the combined treatment group (8.1 vs 5.7 months, P = 0.19). In cisplatin study a pain response was observed in 10 of 12 (83%) evaluable patients, 5/6 in Arm 1 and 4/6 in Arm 2. CONCLUSIONS: Low-dose platinum compounds seem to enhance the effects of 89Sr radioisotope therapy on pain from bone metastases without relevant hematological toxicity.


Subject(s)
Bone Neoplasms/secondary , Platinum Compounds/therapeutic use , Radiation-Sensitizing Agents/therapeutic use , Strontium Radioisotopes/therapeutic use , Bone Neoplasms/radiotherapy , Humans
17.
Radiol Med ; 96(4): 394-8, 1998 Oct.
Article in Italian | MEDLINE | ID: mdl-9972221

ABSTRACT

To comply with regulations on radiation protection and quality controls is a difficult task when operating in large hospitals. This leads to the need of defining more efficient protocols and of making procedures as automated as possible. The procedure described in this paper is based on a multimeter controlled by a portable PC, and on a spreadsheet program for data processing. Multimeter data are automatically imported and processed, in order to assess the compliance of measured parameters with the reference regulations (IEC recommendations, radiation safety rules, etc.). The spreadsheet is permanently linked to a data base. It is therefore possible to perform the controls and to store the corresponding results in a shorter time (one hour per machine, approximately). By using a properly chosen quality index, monitoring the efficiency of the diagnostic equipment is also possible, which allows to prevent the onset of severe failures.


Subject(s)
Quality Control , Radiation Protection , Radiology , Computers
18.
J Nucl Med ; 38(10): 1546-51, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9379190

ABSTRACT

UNLABELLED: Presurgical neoadjuvant chemotherapy (PSNC) is the treatment of choice for patients with locally advanced breast carcinoma (LABC). Accurate assessment of tumor response is important in planning subsequent treatments. Conventional response assessment by mammography and clinical evaluation is not fully reliable. This study evaluates the diagnostic yield of serial 99mTc-MIBI scintigraphy in the assessment of LABC response to PSNC. METHODS: Twenty-nine patients affected by LABC underwent clinical, mammographic and 99mTc-MIBI scintigraphy before and after 3 cycles of FEC (500 mg/m2 5-fluorouracil, 50 mg/m2 epirubicin and 400 mg/m2 cyclophosphamide) on Days 1 and 8. Surgery was planned for 15 days after the third cycle of chemotherapy. Pathological status was obtained after surgery in all patients. RESULTS: Sensitivities (i.e., true-positive ratios) for a correct prediction of tumor presence after PSNC were 65% for scintigraphy, 35% for clinical evaluation and 69% for mammography. Specificities (i.e., true-negative ratios) for a correct prediction of tumor absence after PSNC were 100% for scintigraphy, 67% for clinical evaluation and 33% for mammography. Technetium-99m-MIBI uptake in this series did not correlate with P-170 expression, proliferating cell nuclear antigen, Her-2/neu oncogene protein, antihuman endothelial cell CD31 antigen and estrogenic and progestinic receptor status. CONCLUSION: Technetium-99m-MIBI scintigraphy is effective in monitoring the response to PSNC in LABC patients. Its diagnostic yield is clearly superior to clinical evaluation alone. Scintigraphy performs as does mammography in patients with negative response, but it is clearly superior in patients with positive response.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/diagnostic imaging , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Breast Neoplasms/drug therapy , Breast Neoplasms/surgery , Chemotherapy, Adjuvant , Cyclophosphamide/administration & dosage , Epirubicin/administration & dosage , Female , Fluorouracil/administration & dosage , Humans , Radionuclide Imaging , Sensitivity and Specificity , Stereoisomerism
19.
Acta Oncol ; 36(7): 761-4, 1997.
Article in English | MEDLINE | ID: mdl-9490097

ABSTRACT

S-100 protein and neuron-specific enolase (NSE) have recently been proposed as serum markers for melanoma. In this study NSE and S-100 serum levels were assayed by commercial IRMA methods in 53 patients with melanoma. The overall prevalence of abnormal marker levels was similar for NSE (26%) and S-100 (30%). The 24 patients in stages I and II had uniformly normal S-100 levels, but abnormal NSE levels were observed in 3 out of the 12 patients in stage II (33%) and in 1 out of 12 in stage I. NSE appears thus to be the marker of choice in the early stages, where its increase points to disease progression. In patients in stages III and IV the prevalence of abnormal values was 34% for NSE and 55% for S-100 (p = < 0.05). In the latter group diagnostic sensitivity increased to 62% if isolated elevation of each marker was considered. In patients with advanced stage disease, both NSE and S-100 should be assayed.


Subject(s)
Biomarkers, Tumor/blood , Melanoma/blood , Phosphopyruvate Hydratase/blood , S100 Proteins/blood , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Melanoma/enzymology , Melanoma/pathology , Middle Aged , Neoplasm Staging
20.
J Nucl Cardiol ; 4(6): 502-8, 1997.
Article in English | MEDLINE | ID: mdl-9456190

ABSTRACT

BACKGROUND: Cardiotoxicity is the major limiting factor in anthracycline chemotherapy of advanced neoplastic disease. Epirubicin shows a more favorable therapeutic index than does doxorubicin, but it is still cardiotoxic. Limited data regarding epirubicin cardiotoxicity are available, and suggested guidelines for doxorubicin with left ventricular ejection fraction (LVEF) measurement may not be empirically useful for epirubicin therapy. This study evaluates the diagnostic role of antimyosin immunoscintigraphy for early identification of patients at risk for late pump dysfunction from cardiotoxicity induced by high-dose administration of epirubicin up to high cumulative dosages. METHODS AND RESULTS: Chemotherapy with epirubicin was administered to 36 patients with cancer at a dosing rate of 160 mg/m2 as a bolus injection every 21 days to a cumulative dosage of 960 mg/m2. Radionuclide angiography (LVEF) and antimyosin immunoscintigraphy with heart-lung ratio (HLR) measurements were performed before chemotherapy, at intermediate cumulative epirubicin dosages, at the end of treatment, and during the follow-up. LVEF decreased significantly at the end of the treatment and after therapy discontinuation. HLR values were significantly increased at intermediate epirubicin dosage levels and continued to increase to the end of the treatment but thereafter remained substantially unmodified for 3 to 6 months after therapy discontinuation. A value of HLR >1.85 at intermediate epirubicin dosage level showed a sensitivity of 95% and a specificity of 57% as a predictor of late LVEF impairment. CONCLUSIONS: LVEF appears more useful at high cumulative dosages and during follow-up to monitor late pump dysfunction, whereas HLR may be effective during the early phase of the therapy in determining which patients are at risk for development of late cardiac dysfunction.


Subject(s)
Antibiotics, Antineoplastic/adverse effects , Breast Neoplasms/drug therapy , Epirubicin/adverse effects , Heart/diagnostic imaging , Myosins/immunology , Radioimmunodetection , Sarcoma/drug therapy , Stroke Volume/drug effects , Ventricular Function, Left/drug effects , Adolescent , Adult , Aged , Humans , Middle Aged , Radionuclide Angiography , Risk Assessment
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