A new detector for the beam energy measurement in proton therapy: a feasibility study.

The proof of concept of a new device, capable of determining in a few seconds the energy of clinical proton beams by measuring the time of flight (ToF) of protons, is presented. The prototype consists of two thin ultra fast silicon detector (UFSD) pads, aligned along the beam direction in a telescope configuration and readout by a digitizer. The method developed for extracting the energy at the isocenter from the measured ToF, validated by Monte Carlo simulations, and the procedure used to calibrate the system are also presented and discussed in detail. The prototype was tested at the Centro Nazionale di Adroterapia Oncologica (CNAO, Pavia, Italy), at several beam energies, covering the entire clinical range, and using different distances between the sensors. The measured beam energies were benchmarked against the nominal CNAO energy values, obtained during the commissioning of the centre from the measured ranges in water. Deviations of few hundreds of keV have been achieved for all considered proton beam energies for distances between the two sensors larger than 60 cm, indicating a sensitivity to the corresponding beam range in water smaller than the clinical tolerance of 1 mm. Moreover, few seconds of irradiation were necessary to collect the required statistics. These preliminary results indicate that a telescope of UFSDs could achieve in a short time the accuracy required for the clinical application and therefore encourage further investigations towards the improvement and the optimization of the present prototype.

RIDOS: A new system for online computation of the delivered dose distributions in scanning ion beam therapy.

PURPOSE: To describe a new system for scanned ion beam therapy, named RIDOS (Real-time Ion DOse planning and delivery System), which performs real time delivered dose verification integrating the information from a clinical beam monitoring system with a Graphic Processing Unit (GPU) based dose calculation in patient Computed Tomography. METHODS: A benchmarked dose computation algorithm for scanned ion beams has been parallelized and adapted to run on a GPU architecture. A workstation equipped with a NVIDIA GPU has been interfaced through a National Instruments PXI-crate with the dose delivery system of the Italian National Center of Oncological Hadrontherapy (CNAO) to receive in real-time the measured beam parameters. Data from a patient monitoring system are also collected to associate the respiratory phases with each spot during the delivery of the dose. Using both measured and planned spot properties, RIDOS evaluates during the few seconds of inter-spill time the cumulative delivered and prescribed dose distributions and compares them through a fast γ-index algorithm. RESULTS: The accuracy of the GPU-based algorithms was assessed against the CPU-based ones and the differences were found below 1‰. The cumulative planned and delivered doses are computed at the end of each spill in about 300 ms, while the dose comparison takes approximatively 400 ms. The whole operation provides the results before the next spill starts. CONCLUSIONS: RIDOS system is able to provide a fast computation of the delivered dose in the inter-spill time of the CNAO facility and allows to monitor online the dose deposition accuracy all along the treatment.

'Survival': a simulation toolkit introducing a modular approach for radiobiological evaluations in ion beam therapy.

One major rationale for the application of heavy ion beams in tumour therapy is their increased relative biological effectiveness (RBE). The complex dependencies of the RBE on dose, biological endpoint, position in the field etc require the use of biophysical models in treatment planning and clinical analysis. This study aims to introduce a new software, named 'Survival', to facilitate the radiobiological computations needed in ion therapy. The simulation toolkit was written in C++ and it was developed with a modular architecture in order to easily incorporate different radiobiological models. The following models were successfully implemented: the local effect model (LEM, version I, II and III) and variants of the microdosimetric-kinetic model (MKM). Different numerical evaluation approaches were also implemented: Monte Carlo (MC) numerical methods and a set of faster analytical approximations. Among the possible applications, the toolkit was used to reproduce the RBE versus LET for different ions (proton, He, C, O, Ne) and different cell lines (CHO, HSG). Intercomparison between different models (LEM and MKM) and computational approaches (MC and fast approximations) were performed. The developed software could represent an important tool for the evaluation of the biological effectiveness of charged particles in ion beam therapy, in particular when coupled with treatment simulations. Its modular architecture facilitates benchmarking and inter-comparison between different models and evaluation approaches. The code is open source (GPL2 license) and available at https://github.com/batuff/Survival.

Review of technologies and procedures of clinical dosimetry for scanned ion beam radiotherapy.

In the last few years, the use of ions in radiation therapy is gaining interest and it is being considered medically necessary for a growing subset of tumours. Concurrently, the technologies involved in a particle therapy treatment are rapidly evolving, as well as the accuracy in the dose delivery in spite of the increased complexity. Since nowadays, the pencil beam scanning technique is showing very interesting features in terms of dose conformation and overall treatment outcome, the present review is intended to summarize the main procedures, detectors and tools adopted for the clinical dose verification. A list of dose measurements is provided, with the aim of being a valuable guidance for starting and future particle therapy facilities. Absorbed dose to water, relative dose, fluence and surrogates of the delivered dose are the main quantities measured by means of different detectors, specifically developed for point-like, 1D or 2D measurements. The dosimetric procedures are here categorized according to their purpose, distinguishing between system commissioning and clinical quality assurance. A separate discussion is dedicated to patient specific, in vivo and 4D dose verification, which aim at assessing the actual delivered dose. Together with the description of the currently used methods, challenges and perspectives toward an increasingly accurate and fast dose verification strategy are discussed.

Quality assurance of carbon ion and proton beams: A feasibility study for using the 2D MatriXX detector.

PURPOSE: The quality assurance (QA) procedures in particle therapy centers with active beam scanning make extensive use of films, which do not provide immediate results. The purpose of this work is to verify whether the 2D MatriXX detector by IBA Dosimetry has enough sensitivity to replace films in some of the measurements. METHODS: MatriXX is a commercial detector composed of 32×32 parallel plate ionization chambers designed for pre-treatment dose verification in conventional radiation therapy. The detector and GAFCHROMIC® films were exposed simultaneously to a 131.44MeV proton and a 221.45MeV/u carbon-ion therapeutic beam at the CNAO therapy center of Pavia - Italy, and the results were analyzed and compared. RESULTS: The sensitivity MatriXX on the beam position, beam width and field flatness was investigated. For the first two quantities, a method for correcting systematic uncertainties, dependent on the beam size, was developed allowing to achieve a position resolution equal to 230µm for carbon ions and less than 100µm for protons. The beam size and the field flatness measured using MatriXX were compared with the same quantities measured with the irradiated film, showing a good agreement. CONCLUSIONS: The results indicate that a 2D detector such as MatriXX can be used to measure several parameters of a scanned ion beam quickly and precisely and suggest that the QA would benefit from a new protocol where the MatriXX detector is added to the existing systems.

Texture features on T2-weighted magnetic resonance imaging: new potential biomarkers for prostate cancer aggressiveness.

To explore contrast (C) and homogeneity (H) gray-level co-occurrence matrix texture features on T2-weighted (T2w) Magnetic Resonance (MR) images and apparent diffusion coefficient (ADC) maps for predicting prostate cancer (PCa) aggressiveness, and to compare them with traditional ADC metrics for differentiating low- from intermediate/high-grade PCas. The local Ethics Committee approved this prospective study of 93 patients (median age, 65 years), who underwent 1.5 T multiparametric endorectal MR imaging before prostatectomy. Clinically significant (volume ≥0.5 ml) peripheral tumours were outlined on histological sections, contoured on T2w and ADC images, and their pathological Gleason Score (pGS) was recorded. C, H, and traditional ADC metrics (mean, median, 10th and 25th percentile) were calculated on the largest lesion slice, and correlated with the pGS through the Spearman correlation coefficient. The area under the receiver operating characteristic curve (AUC) assessed how parameters differentiate pGS = 6 from pGS ≥ 7. The dataset included 49 clinically significant PCas with a balanced distribution of pGS. The Spearman ρ and AUC values on ADC were: -0.489, 0.823 (mean); -0.522, 0.821 (median); -0.569, 0.854 (10th percentile); -0.556, 0.854 (25th percentile); -0.386, 0.871 (C); 0.533, 0.923 (H); while on T2w they were: -0.654, 0.945 (C); 0.645, 0.962 (H). AUC of H on ADC and T2w, and C on T2w were significantly higher than that of the mean ADC (p = 0.05). H and C calculated on T2w images outperform ADC parameters in correlating with pGS and differentiating low- from intermediate/high-risk PCas, supporting the role of T2w MR imaging in assessing PCa biological aggressiveness.

A new algorithm for automatic vascular mapping of DCE-MRI of the breast: Clinical application of a potential new biomarker.

BACKGROUND AND OBJECTIVE: Vascularity evaluation on breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has a potential diagnostic value, but it represents a time consuming procedure, affected by intra- and inter-observer variability. This study tests the application of a recently published method to reproducibly quantify breast vascularity, and evaluates if the vascular volume of cancer-bearing breast, calculated from automatic vascular maps (AVMs), may correlate with pathologic tumor response after neoadjuvant chemotherapy (NAC). METHODS: Twenty-four patients with unilateral locally advanced breast cancer underwent DCE-MRI before and after NAC, 8 responders and 16 non-responders. A validated algorithm, based on multiscale 3D Hessian matrix analysis, provided AVMs and allowed the calculation of vessel volume before the initiation and after the last NAC cycle for each breast. For cancer bearing breast, the difference in vascular volume before and after NAC was compared in responders and non-responders using the Wilcoxon two-sample test. A radiologist evaluated the vascularity on the subtracted images (first enhanced minus unenhanced), before and after treatment, assigning a vascular score for each breast, according to the number of vessels with length ≥30mm and maximal transverse diameter ≥2mm. The same evaluation was repeated with the support of the simultaneous visualization of the AVMs. The two evaluations were compared in terms of mean number of vessels and mean vascular score per breast, in responders and non-responders, by use of Wilcoxon two sample test. For all the analysis, the statistical significance level was set at 0.05. RESULTS: For breasts harboring the cancer, evidence of a difference in vascular volume before and after NAC for responders (median=1.71cc) and non-responders (median=0.41cc) was found (p=0.003). A significant difference was also found in the number of vessels (p=0.03) and vascular score (p=0.02) before or after NAC, according to the evaluation supported by the AVMs. CONCLUSIONS: The encouraging, although preliminary, results of this study suggest the use of AVMs as new biomarker to evaluate the pathologic response after NAC, but also support their application in other breast DCE-MRI vessel analysis that are waiting for a reliable quantification method.

Computer-aided diagnosis for dynamic contrast-enhanced breast MRI of mass-like lesions using a multiparametric model combining a selection of morphological, kinetic, and spatiotemporal features.

PURPOSE: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a radiological tool for the detection and discrimination of breast lesions. The aim of this study is to evaluate a computer-aided diagnosis (CAD) system for discriminating malignant from benign breast lesions at DCE-MRI by the combined use of morphological, kinetic, and spatiotemporal lesion features. METHODS: Fifty-four malignant and 19 benign breast lesions in 51 patients were retrospectively evaluated. Images were acquired at two centers at 1.5 T. Mass-like lesions were automatically segmented after image normalization and elastic coregistration of contrast-enhanced frames. For each lesion, a set of 28 3D features were extracted: ten morphological (related to shape, margins, and internal enhancement distribution); nine kinetic (computed from signal-to-time curves); and nine spatiotemporal (related to the variation of the signal between adjacent frames). A support vector machine (SVM) was trained with feature subsets selected by a genetic search. Best subsets were composed of the most frequent features selected by majority rule. The performance was measured by receiver operator characteristics analysis with a stratified tenfold cross-validation and bootstrap method for confidence intervals. RESULTS: SVM training by the three separated classes of features resulted in an area under the curve (AUC) of 0.90 ± 0.04 (mean ± standard deviation), 0.87 ± 0.06, and 0.86 ± 0.06 for morphological, kinetic, and spatiotemporal feature, respectively. Combined training with all 28 features resulted in AUC of 0.96 ± 0.02 obtained with a selected feature subset composed by two morphological, one kinetic, and two spatiotemporal features. CONCLUSIONS: Quantitative combination of morphological, kinetic, and spatiotemporal features is feasible and provides a higher discriminating power than using the three different classes of features separately.

Comparative evaluation of genome-wide gene expression profiles in ruptured and unruptured human intracranial aneurysms.

Few studies have evaluated the over or the underexpression of genes directly in samples of aneurysmal wall and extracranial pericranial vascular tissue to investigate the genetic influence in formation and rupture of intracranial aneurysms. We present the results obtained using the DNA microarray technique analysis on sample tissues collected during surgery. We collected and analyzed 12 aneurismal and 9 peripheral arteries (superficial temporal (STA) and middle meningeal artery (MMA) specimens from ruptured aneurysm group patients (13 cases), 10 aneurismal and 12 STA and MMA samples from unruptured aneurysm group patients (14 cases) and 5 STA and MMA artery specimens from control group patients (4 cases). Total RNA was isolated from samples and subjected to cDNA microarray analysis with the use of the human genome U133A GeneChip oligonucleotide microarray (Affymetrix, Santa Clara, CA), which allows to analyze a total number of 14,500 genes in the same time. For genes of interest, real-time RT-PCR was performed to confirm their expression level. Total RNA was isolated from samples and subjected to DNA microarray analysis with the use of the human genome U133A GeneChip oligonucleotide microarray, which allows to analyze a total number of 14,500 genes at the same time. For genes of interest, real-time RT-PCR was performed to confirm their expression level. Regarding ruptured aneurysms, genes were identified showing differential expressions (overexpressed or downregulated) pertaining to specific pathways, particularly those for the structural proteins of the extracellular matrix, members of matrix metalloproteinase (MMP) family (which resulted as being overexpressed) and genes involved in apoptotic phenomena. Particularly, real-time RT-PCR analysis confirmed the upregulation of MMP-2, MMP-9 and pro-apoptotic genes, such as Fas, Bax and Bid, and the downregulation of anti-apoptotic genes, such as Bcl-X(L) and Bcl-2. In a compared analyses of ruptured vs unruptured aneurysms, a different expression was also detected regarding gene coding the tissue inhibitor of matrix metalloproteinases 3 (TIMP-3), which appeared markedly downregulated in unruptured aneurysms, where its expression in unruptured aneurysms was similar to that observed in controls. Another gene differently expressed is nitric oxide synthase (iNOS), which appeared overexpressed in ruptured aneurysms when compared to unruptured aneurysms. Our study is the first, to our knowledge, that compares gene expression profiles (genoma-wide) in intracranial aneurysms. The results of our study suggest that the inhibitor of the metalloproteinase, the pathway of nitric oxide and the apoptotic process play a key-role in reducing the resistance of the arterial wall, that can result in formation and rupture of the intracranial aneurysms.

Gated blood pool tomography for the evaluation of global and regional left ventricular function in comparison to planar techniques and echocardiography.

BACKGROUND: Multigated radionuclide ventriculography (MUGA) is a simple and reliable tool for the assessment of global systolic and diastolic function and in several studies it is still considered a standard for the assessment of left ventricular ejection fraction. However the evaluation of regional wall motion by MUGA is critical due to two-dimensional imaging and its clinical use is progressively declining in favor of echocardiography. Tomographic MUGA (T-MUGA) is not widely adopted in clinical practice. The aim of this study was to compare T-MUGA to planar MUGA (P-MUGA) for the assessment of global ejection fraction and to transthoracic echocardiography for the evaluation of regional wall motion. METHODS: A 16-segment model was adopted for the comparison with echo regional wall motion. For each one of the 16 segments the normal range of T-MUGA ejection fraction was quantified and a normal data file was defined; the average value -2.5 SD was used as the lower threshold to identify abnormal segments. In addition, amplitude images from Fourier analysis were quantified and considered abnormal according to three different thresholds (25, 50 and 75% of the maximum). RESULTS: In a study group of 33 consecutive patients the ejection fraction values of T-MUGA highly correlated with those of P-MUGA (r = 0.93). The regional ejection fraction (according to the normal database) and the amplitude analysis (50% threshold) allowed for the correct identification of 203/226 and 167/226 asynergic segments by echocardiography, and of 269/302 and 244/302 normal segments, respectively. Therefore sensitivity, specificity and overall accuracy to detect regional wall motion abnormalities were 90, 89, 89% and 74, 81, 79% for regional ejection fraction and amplitude analysis, respectively. CONCLUSIONS: T-MUGA is a reliable tool for regional wall motion evaluation, well correlated with echocardiography, less subjective and able to provide quantitative data.

Hepatocarcinoma: considerations on surgical treatment in a personal series of 23 patients.

BACKGROUND/AIMS: Surgical treatment of primary liver tumors has undergone significant changes in recent years because of improved surgical and anesthesiological techniques and better pre- and post-operative care. We review our personal series from 1987-1995. METHODOLOGY: Of 31 cases of hepatocellular carcinoma (HCC) observed in the years 1987-1995, 23 underwent curative resective surgery for a total of 24 liver resections: 6 hepatectomies; 10 segmentectomies; 4 atypical subsegmentectomies; 2 extended resections, with excision of neoplastic thrombi within the portal vein; 1 orthotopic liver transplantation in another institution, and 1 limited segmental resection for tumor recurrence. In 7 recent cases, pre-operative transcatheter arterial chemoembolization (TAE) was used. RESULTS: The mean survival of the 13 patients that are known to be deceased is 27 months (range: 7-114 months). Perioperative mortality was nil. Actuarial 5-year survival rate is 27%. Pre-operative TAE was used in 7 patients: 4 out of 7 lesions were significantly reduced at computed tomography (CT) scan control 21 days following TAE, while in 3 the tumor size was unchanged. CONCLUSIONS: Liver surgery, even major resections, has become safe with no perioperative mortality in our series. In our experience, pre-operative TAE has often produced significant reduction of the mass, but its real efficacy is still the subject of debate. TAE and percutaneous ethanol injection (PET) should be evaluated as part of combined multimodality treatment in the therapy of large lesions previously considered inoperable.

Differentiated thyroid carcinoma in children and adolescents: a 37-year experience in 85 patients.

UNLABELLED: This study reports on 85 differentiated thyroid carcinoma (DTC) (72 papillary, 13 follicular) patients, younger than 18 yr of age at the time of diagnosis, consecutively treated during the period 1958-1995. METHODS: Follow-up (median: 111 mo, range 1-324 mo) consisted of clinical examination, serum thyroglobulin (Tg), 131I whole-body scintigraphy (whole-body scan) and other imaging procedures. RESULTS: Forty-six patients had undergone total thyroidectomy, 38 partial thyroidectomy and 1 thyroid biopsy. In 47 patients, lymph-adenectomy was also performed. Five patients were treated after surgery by external radiotherapy, 59 by 131I therapy and 16 by both modalities. Iodine-131 therapy was successful in ablating thyroid remnants in 35/48 cases, lymph node metastases in 8/11 cases and lung metastases in 12/16 cases. Among the patients with scintigraphic-confirmed disappearance of lung metastases, serum Tg was still detectable in 10 cases, but continued to decrease spontaneously even without further therapeutic doses of 131I. All patients were still alive after a median period of 137 mo (range 5-444 mo). Six patients experienced a recurrence of the disease in the neck. Sixty-seven patients were free of disease, 3 had lymph node metastases, 4 lung metastases and 11 had detectable levels of Tg without demonstrable metastases. No impairment of female fertility or untoward genetic effects were noticed. One male patient, treated with 3.33 GBq of 131I, was infertile due to oligospermia. One case of gastric cancer and one of breast cancer occurred 8 and 19 yr, respectively, after 131I therapy. CONCLUSION: Iodine-131 therapy is highly effective in reducing lung metastases, but undetectable levels of Tg are seldom achieved. Total thyroidectomy and 131I therapy is an effective and safe treatment for the majority of patients with DTC diagnosed in childhood or adolescence.

Basilar artery migraine: transcranial Doppler EEG and SPECT from the aura phase to the end.

Transcranial Doppler, electroencephalography, and single photon emission computed tomography were performed in a case of basilar migraine during the different phases of the attack. In the aura phase, the patient had bilateral blindness and ataxia. Doppler ultrasound studies showed a reduction in the mean flow velocity of the posterior cerebral arteries, electroencephalography showed slow activity confined to the posterior regions, and single photon emission computed tomography, an area of hypoperfusion in the right parietal and occipital regions. During the headache phase, when the neurological examination was normal, transcranial Doppler showed an increase in the mean flow velocity of both posterior cerebral arteries and the electroencephalogram revealed an increase in the slow activity over the occipital regions. When the pain subsided, the electroencephalogram showed a progressive reduction of the slow abnormalities and transcranial Doppler was reported as normal. After a week, single photon emission computed tomography and cranial magnetic resonance imaging were normal. After a month, a follow-up electroencephalogram was also normal. All these findings indicated a transient focal reduction of cerebral blood flow during the aura phase.

Assessment of female fertility and carcinogenesis after iodine-131 therapy for differentiated thyroid carcinoma.

UNLABELLED: The aim of this study was to evaluate female fertility, carcinogenic, and genetic effects after treatment with 131I of differentiated thyroid carcinoma. METHODS: A total of 814 females of child-bearing age were studied. The fertility of 627 females who received 131I therapy was compared to 187 untreated females. Birth histories of the children born from these women were registered. The carcinogenic effect was evaluated by comparing the incidence of tumors in 730 patients treated with 131I with an internal control group, as well as with local population incidence. RESULTS: There was no significant difference in the fertility rate, birth weight and prematurity between the two groups. Only one case of a ventricular septal defect was observed in a child born to a women treated with 131I. The overall standardized incidence ratio (SIR) of second tumors was 1.19 (95% CI: 0.76-1.77) in patients treated with 131I. An elevated SIR was registered for salivary gland tumors and melanoma. No case of leukemia was registered. CONCLUSION: The risk of long-term effects of 131I treatment of differentiated thyroid carcinoma is quite low. Iodine-131 may be safely used in treating cases with a high risk of recurrence.

[Changes in lipid status during pravastatin treatment]. / Modificazioni del quadro lipidico durante trattamento con pravastatina.

Reduced cholesterolemia lowers the risk of ischemic cardiopathy, especially if LDL cholesterol levels are reduced. Today this effect can be achieved using drugs following the discovery of a new class of molecules: statins are specific inhibitors of HMG-CoA-reductase, a key enzyme in cholesterol biosynthesis. These molecules act by modifying the intracellular quota of cholesterol, especially at a hepatocytic level, thus enabling an enhanced expression of those genes responsible for forming receptors for membrane LDL with an increased number of receptors. This leads to a modulation of receptor activity which interferes with LDL uptake, promoting more rapid clearance. The aim of this study was to confirm the efficacy and tolerability of pravastatin when used for long periods in patients with high cholesterol levels, and to compare its activity to that of gemfibrozil.

Erythrocyte antioxidant activity, serum ceruloplasmin, and trace element levels in subjects with alcoholic liver disease.

Erythrocyte antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and reduced glutathione, serum ceruloplasmin, and serum trace elements (copper, zinc, iron, and selenium) related to antioxidant enzymes were assayed in subjects with alcoholic liver disease of different degrees of severity. The erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis had an unbalanced antioxidant system (normal superoxide dismutase, low catalase and glutathione peroxidase activities, and low glutathione content). Serum ceruloplasmin levels were in the normal range. Levels of the serum trace elements zinc and selenium were significantly low in subjects with moderate and severe cirrhosis, whose red cell half-life was also significantly short, as measured by radioactive chromium. These data suggest that the erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis are less protected against oxidant stress. The particular erythrocyte antioxidant system and serum trace element pattern may play a role in the genesis of hemolytic disorders and of alcoholic hepatic damage.

Preliminary results of [131]metaiodobenzylguanidine treatment in metastatic malignant pheochromocytoma.

The poor results of traditional therapy (for purposes of recovery or palliation) in malignant pheochromocytoma and the well proven uptake of [131I]metaiodobenzylguanidine (131I-MIBG) shown by these tumors, induced us to evaluate the clinical usefulness of radiometabolic therapy with 131I-MIBG. Four patients with malignant pheochromocytoma were subjected to 131I-MIBG therapy, between 1987 and 1991, in our department. They all were in an advanced stage of the disease and showed severe symptoms and poor reaction to traditional therapy. The cumulative activity given was 7.4-22.2 GBq. All patients demonstrated transient subjective improvement; in addition, both biochemical and haemodynamic parameters ameliorated. Two patients showed a reduction in the size and number of metastases seen on scintigraphy. One patient died due to progression of the disease. Three patients are still alive and in good condition. No remarkable early or late side-effects were reported. We suggest that 131I-MIBG radiometabolic therapy in advanced-stage malignant pheochromocytoma could be useful in reducing symptoms. Further investigation might show whether a greater reduction in the size of the tumor could be achieved using different therapeutic schedules or by treating the disease in its earlier stages.

Preliminary results of [131I]metaiodobenzylguanidine treatment in metastatic carcinoid tumors.

The successful use of [131I]metaiodobenzylguanidine (131I-MIBG) in the scintigraphic localisation and treatment of several tumors deriving from neuroectoderm has led us to its application in metastatic carcinoid tumors. We selected five patients (two men and three women; age range 53-79 years) who showed progression of the disease with severe related symptoms, poor response to traditional therapy and a good uptake of 131I-MIBG in neoplastic tissue. A cumulative radioactivity of 3.7-22.2 GBq was given. All patients had a clear subjective improvement with a better quality of life for a period of 2-36 months, sometimes accompanied by decreased 5-hydroxyindoleacetic acid urinary excretion. Results concerning objective remission of the disease were unsatisfactory. No remarkable early or late side-effect was noted. We believe 131I-MIBG is useful for symptomatic treatment of metastatic carcinoid in seriously ill patients too. Different treatment schedule and recruitment of patients with less advanced disease could make pathological remission a possible goal.