The prognostic value of baseline (18)F-FDG PET/CT in steroid-naïve large-vessel vasculitis: introduction of volume-based parameters.

PURPOSE: The aim of this study was to analyse if the result of a baseline (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT scan, in large-vessel vasculitis (LVV) patients, is able to predict the course of the disease, not only in terms of presence/absence of final complications but also in terms of favourable/complicated progress (response to steroid therapy, time to steroid suspension, relapses, etc.). METHODS: A total of 46 consecutive patients, who underwent (18)F-FDG PET/CT between May 2010 and March 2013 for fever of unknown origin (FUO) or suspected vasculitis (before starting corticosteroid therapy), were enrolled. The diagnosis of LVV was confirmed in 17 patients. Considering follow-up results, positive LVV patients were divided into two groups, one characterized by favourable (nine) and the other by complicated progress (eight), on the basis of presence/absence of vascular complications, presence/absence of at least another positive PET/CT during follow-up and impossibility to comply with the tapering schedule of the steroid due to biochemical/symptomatic relapse. Vessel uptake in subjects of the two groups was compared in terms of intensity and extension. To evaluate the extent of active disease, we introduced two volume-based parameters: "volume of increased uptake" (VIU) and "total lesion glycolysis" (TLG). The threshold used to calculate VIU on vessel walls was obtained by the "vessel to liver" ratio by means of receiver-operating characteristic analysis and was set at 0.92 × liver maximum standardized uptake value in each patient. RESULTS: Measures of tracer uptake intensity were significantly higher in patients with complicated progress compared to those with a favourable one (p < 0.05). Measures of disease extension were even more significant and TLG emerged as the best parameter to separate the two groups of patients (p = 0.01). CONCLUSION: This pilot study shows that, in LVV patients, the combined evaluation of the intensity and the extension of FDG vessel uptake at diagnosis can predict the clinical course of the disease, separating patients with favourable or complicated progress.

New radiopharmaceutical agents for the treatment of castration-resistant prostate cancer.

Prostate cancer (PCa) is the fourth most common cancer worldwide in terms of incidence and third among male, but is becoming the most common cancer in developed countries. In many patients the disease will progress despite of castration levels of testosterone, to become castration-resistant PCa (CRPC). Nearly all patients with CRPC show bone metastases. The treatment of patients with bony metastases has dramatically changed during the past three years because of new therapeutic approaches addressed to obtain pain control, reduced skeletal morbidity, and most importantly, increased survival rate. A possible therapy can be based also on the use of radiopharmaceuticals systemically administered to slow or reverse the bone metastatic progression. In facts bone-homing radiopharmaceuticals are taken up in areas of high bone turnover, including areas with high osteoblastic activity. Recently, a bone targeting radiopharmaceutical, Radium-223 dichloride was added to this group of drugs clearly representing a new generation of radiopharmaceutical in bone therapy. Clinical trials had shown that the treatment with Ra-223 allowed the reduction of the risk of death respect to placebo. No other radiometabolic treatment achieved such result, evidentiating the disease-modifying properties of this bone-homing radiopharmaceutical. In an effort to treat patients with disseminated PCa, who became resistant to hormonal therapy, molecular targets have been recently identified. Prostate specific membrane antigen (PSMA) is one attractive target for diagnosis and therapy of metastasized PCa since its expression levels are directly correlated to androgen independence, metastasis, and progression. Gastrin-releasing peptide receptors (GRPr) are also highly overexpressed in PCa. Numerous studies suggest the possibility of a high PCa-specific signal with radiolabeled bombesin analogs targeting GRPr. Low molecular weight peptides directed against these molecular targets have been radiolabeled with positron emitting radionuclides such as 68Ga in order to improve sensitivity and specificity for detecting primary, metastatic, and recurrent PCa by PET/CT over conventional imaging techniques. Although peptide radionuclide ligand therapy studies have just initiated, the diagnostic relevance of 68Ga labeled specific tracers has already been established its clinical utility and represents a valid tool against this common and deadly cancer.

The widened use of exogenous stimulation with recombinant human TSH to treat metastatic thyroid carcinoma in Italy.

Recently, in Italy, the reimbursement for the use of rhTSH in preparing patients for radiometabolic treatment of iodine-avid metastases from differentiated thyroid cancer has been made possible. Intramuscular administration of rhTSH increases the radioiodine uptake and thyroglobulin production by thyroid cells. In addition to the previous indications on the use of rhTSH (mainly: serum thyreoglobulin assay with or without 131I scintigraphy and ablation with 131I of remnants in low risk patients), the reimbursement is now allowed for the treatment with radioiodine of iodine-avid loco-regional and distant metastases, in subjects with inability to reach adequate TSH levels and/or severe clinical conditions which could be potentially worsened by other concurrent diseases (history of stroke or transient ischemic attack, severe cardiac disease, renal failure or major psychiatric disorders). The Italian Medicines Agency (AIFA) approved this use (and added this hormone in the special list of drugs regulated by the D.Lgs 648/96) on the basis of a series of scientific evidences, proposed by a "team of experts". In the present paper we illustrate the scientific background of the use of rhTSH (clinical usefulness, economic considerations, aspects related to a better quality of life) that allowed the modification of the reimbursement and how it was made possible in the Italian legislative context.

[Radiometabolic therapy for metastatic thyroid carcinoma: overview of the literature and rational bases for the use of recombinant human TSH]. / La terapia radiometabolica del carcinoma della tiroide metastatico: overview della letteratura e basi razionali all'utilizzo del TSH umano ricombinante.

The established treatment for differentiated thyroid carcinoma (DTC) is founded on total thyroidectomy and subsequent administration of radioiodine (131I) to ablate the thyroid remnant and to treat the metastatic disease. In the case of metastatic or recurrent disease, further cycles of 131I therapy are often necessary. The condition for maximizing the effectiveness of the treatment is to have an adequate stimulation from TSH, which must be >25-30 mIU/L. This elevation is achieved either discontinuing the hormone suppression therapy for an appropriate period, or administering recombinant human TSH (rhTSH). The latter has shown good clinical efficacy in patients with residual thyroid gland and is nowadays commonly employed since it is easy to use and allows to avoid the side effects of hypothyroidism. It thus represents a good alternative to thyroid hormone withdrawal for the remnant ablation, while is still open the question if its efficacy on the management of metastatic disease is superimposable to thyroid hormone withdrawal. To this purpose, a Panel of expert reviewed the literature, assessing the advantages and disadvantages for the patient, as well as the impact in terms of cost and benefit to the National Health Service. The work of the Panel concluded with a proposal for the use of rhTSH in selected patients with metastatic DTC, in which is considered the efficacy and safety of the product and is examined its use in terms of costs; this proposal was accepted by the Italian Drug Agency resulting in an update of the indications for rhTSH.

Effect of an intensive chemotherapy followed by mediastinal irradiation on pulmonary and cardiac function in advanced Hodgkin's disease.

Mediastinal irradiation combined with chemotherapy in patients with Hodgkin's disease have been associated with cardiopulmonary toxic effects that can last over the years. In this study we monitored pulmonary and cardiac function in 39 patients affected by advanced Hodgkin's disease (stage II B-III and IV) with mediastinal involvement and submitted to an intensive chemotherapy regimen (epirubicin, vincristine, ciclophosphamide, and etoposide) followed by involved field irradiation. Pulmonary function was verified with chest x-ray, spirometric parameters, arterial blood gas analysis, single breath CO transfer factor (DLCO), and its components Dm and Vc. Cardiac function was verified with electrocardiogram (EKG) and left ventricular ejection fraction (LVEF) by means of radionuclide angiocardiography. The median follow-up was 40 months. Spirometric parameters did no show modifications at the end of treatment, on the contrary they improved during the follow-up. Chest x-ray showed radiographic parenchimal damage in 51% of patients. DLCO remained constantly decreased. sEKG did not show significant modification, whereas LVEF significantly decreased at the end of treatment and remained persistently decreased during follow-up. None of the patients with reduction of DLCO or LVEF showed clinical symptoms of heart and pulmonary dysfunctions. One patient, 49 years old, suffered from myocardial infarction 25 months after the completion of radio-chemotherapy. These data indicate that this combined regimen can induce persistent pulmonary and cardiac damages at subclinical level.

Bone scintigraphy and the added value of SPECT (single photon emission tomography) in detecting skeletal lesions.

Skeletal metastases are one of the major clinical problems for the oncologist. Over the last several decades bone scintigraphy has been used extensively in detecting bone involvement since it can provide information about disease location, prognosis and the effectiveness of treatment. Bone scan offers the advantage of total body examination, and images bone lesions earlier than other techniques. In this paper the main clinical problems related to the most common applications of bone scan in breast, prostate, lung cancer and other tumours are discussed. The experience carried out at the National Cancer Institute of Milan by using bone SPECT to detect single bone metastases is reported. One hundred and eighteen patients with bone metastases (from different tumour types: breast, lung, prostate, lymphomas, etc.) were studied by planar scintigraphy, SPECT and other radiological modalities (CT, MRI or X-rays). The overall performances of bone SPECT were sensitivity: 90.5% (19/21), specificity 92.8% (90/97), positive predictive value 73% (19/26), negative predictive value 97.8% (90/92), accuracy 92.4% (109/118). Considering breast cancer, the most frequent pathology in our series, and the lumbar spinal tract, the most common skeletal segment involved, the figures of merit of SPECT were: sensitivity 100% (4/4), specificity 95.3% (41/43), positive predictive value 66.7% (4/6), negative predictive value 100% (41/41), accuracy 95.7% (45/47). In conclusion bone SPECT showed very good performances, in particular improving the predictive value of planar scan in the diagnosis of vertebral metastases.

Production and validation of the pharmacokinetics of a single-chain Fv fragment of the MGR6 antibody for targeting of tumors expressing HER-2.

The HER-2 antigen, which is overexpressed in many breast carcinomas, is an ideal target for monoclonal antibodies due to its low expression in normal tissue and its homogeneous distribution in the tumor mass. We have developed and characterized the murine MAb MGR6 against HER-2, which is able to inhibit proliferation of tumor cells overexpressing HER-2. On the basis of these preclinical results, phase I studies in breast carcinoma patients were conducted and radiolocalization data indicated an antibody half life which directly paralleled that of other whole antibodies and thus resulting in a limited in vivo diagnostic capacity. To obtain a smaller reagent with possibly improved in vivo properties, a single chain variable fragment (scFv) of the original MGR6-producing hybridoma was generated by phage display technology. Biologically active MGR6 scFv was purified rapidly and at high yield by metal affinity chromatography. Competition FACS and ELISA analyses identified an epitope on the HER-2 extracellular domain that was shared by the scFv and the parental MAb. BlAcore analysis indicated a Koff of 9.3 x 10(-4) s(-1), similar to that of the intact MGR6 MAb. Distribution and elimination half-lives of MGR6 scFv, calculated from in vivo preclinical evaluations, were much faster (13 min and 6.2 h, respectively) than previously published results for the intact MAb (mean t1/2beta of 46 h). This represents a theoretical improvement in pharmacokinetics with respect to the parental murine MAb and points to the potential for utilizing this fragment in redirecting therapeutic agents, such as radioisotopes, to different human carcinomas overexpressing HER-2.

Uptake of tritiated thymidine, deoxyglucose and methionine in three lung cancer cell lines: deoxyglucose uptake mirrors tritiated thymidine uptake.

[(18)F]-fluorodeoxyglucose and [(11)C]-methionine are tracers which are widely used in oncological positron emission tomography. This study has been designed to assess the deoxyglucose and methionine uptake behaviour in three cell lines from different lung cancer histotypes. Tracer uptake was compared with proliferative activity as determined by growth curves and tritiated thymidine uptake. Deoxyglucose paralleled thymidine in all cell lines, peaking in the lag phase, decreasing throughout the exponential phase, and reaching its minimum in the plateau phase. The correlation was statistically verified and Spearman's rho ranged from 0.79 to 0.99. The absolute methionine uptake was always highest and always peaked on day 2, followed by a quite rapid decrease. However, besides the delay in maximum uptake, methionine incorporation was also related to proliferation, although the statistical correlations were weaker. These results show for the first time a clear correlation between deoxyglucose uptake and cell proliferation in a model comparing tracer uptake in different growth phases. Although delayed, methionine uptake was also related to cell growth and its greater intensity could be of interest for clinical use.

State of the art of sentinel node biopsy in oncology.

Sentinel node biopsy has become a standard diagnostic procedure to assess lymph node status of various tumors. The combination of blue dye and a radioactive tracer offers the best chances of identifying the sentinel lymph node. Most progress in the technique of the sentinel node procedure has been made in melanoma and breast cancer. In melanoma, sentinel node biopsy has been introduced as a fundamental procedure for staging. Information on the lymphatic drainage from a melanoma can have a direct impact on the surgery. More recently, the technique has been successfully introduced in the management of breast cancer, in which a large number of unnecessary axillary dissections could be avoided. However, there are many other potential fields of application of the sentinel node biopsy (e.g. endometrial, vulvar, head and neck cancers) that are worthy of investigation. In any case, multicenter trials are required to standardize the procedures, taking into account several variables such as particle size and mode of delivery of the radiotracer, amount of radioactivity administered, number and location of injections, and choice of the hand-held probe. We briefly describe the technical and historical aspects of the sentinel node biopsy and summarize the main clinical trials proposed and/or performed in the field.

Sentinel node biopsy in patients with cutaneous melanoma of the head and neck.

Biopsy of head and neck sentinel nodes (SNs) can be technically problematic due to the unpredictable and variable drainage patterns of this anatomic region. The aim of the present study was to evaluate the feasibility of SN biopsy for cutaneous melanoma of the head and neck. We performed SN biopsy in 17 patients affected by stage I cutaneous melanoma of the head and neck on the basis of lymphoscintigraphy, blue dye and gamma probe. A total of 24 procedures were performed. Drainage to more than one lymphatic basin was observed in five patients (two basins in three cases and three basins in two cases) and in all cases SN biopsy was performed in all basins. The biopsy distribution by site was: six cervical nodes, five parotid nodes, four supraclavicular and submandibular nodes, three auricular and axillary nodes. The SN identification rate was 87.5% (21/24); metastases were discovered in four cases, with a positivity rate of 23.6%. At the time of writing, 1 patient is alive with local disease, 3 patients are dead and 13 are alive and free of disease with a follow-up ranging from 1 to 40 months (median, 21 months) following SN biopsy. In our opinion preoperative lymphoscintigraphy and the intraoperative use of a gamma probe are useful for the identification of lymphatic drainage of cutaneous melanoma of the head and neck.

Unusual association between cutaneous melanoma and axillary metastasis from occult breast cancer detected by sentinel node biopsy.

We report a case of cutaneous Stage I melanoma associated with occult breast cancer detected incidentally during a sentinel node biopsy. A brief review of the literature is presented with particular emphasis on this association and on an examination of the theoretical link which may exist between melanoma and breast cancer.

Current applications and perspectives of diagnostic nuclear medicine in oncology. Task Group of Oncology.

The characteristic of nuclear medicine is that it gives images of organs, structures and physiological or pathological processes, detecting the distribution of several radio-pharmaceuticals according to their uptake and metabolism. Its imaging can provide morphological information while at the same time containing data on cellular activity and functions. Such molecular imaging fulfils the modern orientations of oncology, where there is a need to define the presence of a malignancy in the earliest and most effective way, to characterise the neoplasm in terms of biological characteristics (e. g., proliferation, aggressiveness, differentiation, receptor status) and to obtain fundamental issues in patient management such as evaluation of disease extent, monitoring of therapies and study of treatment-induced side effects. The aim of this position paper is to discuss the main indications of nuclear medicine in diagnostic oncology reporting the most recent developments in nuclear medicine, and an extensive list of the major indications for nuclear medicine procedures. The techniques have been labelled as when considered essential in the diagnostic process, when they can give useful additional or information in combination with other instrumental diagnostic approaches, and alternative when they may be performed instead of other tests. These indications were derived by a general consensus within the Task Group of Oncology of the World Federation of Nuclear Medicine and Biology, and it should be stressed that only the current role of nuclear medicine was considered. The Task Group does not claim to have covered the entire range of nuclear medicine indications; in fact it was agreed to include only the most widely used techniques. The highly specific or very exceptionally used applications, or those still in development or under evaluation in clinical trials were not taken into consideration. The conclusion is that the current relationship between nuclear medicine and oncology can be defined not only as satisfactory but also as extremely promising, as nuclear medicine has the potential to compete with the most advanced radiological techniques of imaging, perhaps not so much in terms of sensitivity but more so in terms of specificity and biological characterisation. Several novel diagnostic procedures are able to solve clinical problems for which traditional radiology has shown clear limitations. Nuclear medicine remains today a dynamic medical specialty because it includes a combination of advances in basic science research, technology, cell biology and medical practice and it cannot be excluded that the new lines of research both towards new radiopharmaceuticals and advanced instrumentation will offer in the future new stimulating opportunities.

Gallium-67 as a tumor-seeking agent in lymphomas--a review.

BACKGROUND: At present 67Ga can be considered one of the most widely used viability radiotracers. There is general consensus in the literature that 67Ga has the highest clinical value in the management of lymphoma patients. METHODS: We critically discuss the role of gallium scintigraphy in lymphoma patients on the basis of the experience of the Nuclear Medicine Division at the National Cancer Institute of Milan. RESULTS AND CONCLUSIONS: The sensitivity of gallium scan is very high (80-90%) in the staging and follow-up of Hodgkin's disease, and the method is also of great importance in the follow-up of lymphoma patients. We recommend scintigraphy to study the residual mediastinal mass after treatment. Our experiences during the follow-up of 189 lymphoma patients clearly showed the superior performance of gallium scan compared to MRI in the study of the mediastinal region after treatment. Sensitivity and specificity were both very high (90% and 96.9% vs 88.7% and 89.2%, respectively). Gallium scintigraphy can also be used to study the disease-free interval, post-treatment survival, early signs of recurrence and treatment response times. Comparison of the survival curves of 33 patients with diffuse large cell Non-Hodgkin's lymphoma examined at the National Cancer Institute showed a statistically significant difference (logrank test, P = 0.0125) between patients with positive and those with negative gallium scan after 4-6 cycles of chemotherapy.

Gallium-67 scintigraphy evaluation of therapy in non-Hodgkin's lymphoma.

UNLABELLED: Patients with diffuse large cell lymphoma may achieve complete remission (CR) after chemotherapy, and the time to reach CR may be predictive of treatment outcome. Partial remission, or recurrence from CR, is associated with poor survival. Gallium-67 imaging has proven to be useful in evaluating lymphoma patients. In tumor models, this radiotracer is an indicator of tumor viability. Gallium-67 uptake is seen only in avid and viable lymphoma tissue, not in fibrotic or necrotic tissue. In this study, we prospectively assessed the ability of this radiotracer to define residual disease. In addition, we evaluated the possibility of predicting the clinical outcome in patients with diffuse cell lymphoma on the basis of scan positivity during chemotherapy. METHODS: Thirty-three consecutive patients with histologically proven diffuse large cell lymphoma were investigated with 67Ga scintigraphy 48-72 hr after injection of 185-259 MBq 67Ga-citrate for staging and during follow-up after four to six cycles of intensive chemotherapy. Patients were monitored for a mean of 56.0 mo (range 7-90 mo), and they were restaged using physical examination, CT and all necessary imaging modalities. RESULTS: Patients were divided into two groups according to the positivity or negativity of 67Ga scan after four to six cycles of chemotherapy. Of the 33 patients studied, 14 (42.4%) showed persistent abnormal uptake of 67Ga-citrate after four to six cycles of chemotherapy. In this group, 9 patients (64.2%) died of lymphoma at a mean of 24.3 mo from presentation with the diagnosis (range 7-71 mo). Four patients had no evidence of disease at an average of 71.7 mo after diagnosis, and 1 patient was considered to be in partial remission. In the second group of 19 67Ga-negative patients, after four to six cycles of chemotherapy, 4 died and 15 are alive and considered to be in CR. A statistical analysis of the association between 67Ga scan results after four to six cycles of chemotherapy and survival was performed using the log-rank test; there was a statistically significant association between scan results and survival (p=0.00125). CONCLUSION: We conclude that 67Ga scintigraphy is an excellent predictor of residual tumor viability in lymphoma patients and that persistent positivity of the scan predicts poor outcome and may justify a change in treatment.

Nuclear medicine approaches for detection of axillary lymph node metastases.

In breast cancer patients the detection of axillary lymph node involvement is a very critical issue, in view of the earlier diagnosis of the disease in recent years, and the increased frequency of very small tumors at first presentation. The size of cancer is related to the risk of axillary metastases, and this may affect the prognosis and the therapeutic strategies. Axillary lymph node involvement is generally recognized as an index of distant microdiffusion, and as it affects overall and disease-free survival, represents the basis for adoption of adjuvant chemotherapy. Routine axillary lymph node dissection (ALND) is expensive, and does not benefit about 70% of early breast cancer patients which are node negative (pN-). Today most of these patients have to sustain the potential morbidity and the economic costs of ALND. The clinical approach is known to be an unreliable diagnostic tool, and for the detection of axillary metastases, conventional X-ray techniques are also unable to solve the problem. By contrast, nuclear medicine procedures have revealed a very interesting diagnostic potential in recent years. This paper analyzes the numerous studies conducted in the field of lymph node visualization and the heterogeneity of the published experiences, taking into account the different approaches proposed in the literature: a) imaging with gamma-emitting tumor seeking agents; b) radioimmunoscintigraphy intravenous (i.v.) or by the interstitial route; c) lymphoscintigraphy with colloids and gamma probe sentinel biopsy; d) positron emission tomography (PET). Although it is very difficult to make a definitive statement about the clinical efficacy of all these methods, this paper reports the most important series of patients examined in the literature as well as the author's own experiences. This can serve as the basis for a better understanding of the potential of nuclear medicine procedures, and gives the reader the opportunity to weigh advantages and drawbacks of each method. At present, lymphoscintigraphy with gamma probe sentinel biopsy and FDG-PET are the nuclear medicine approaches with the best diagnostic performance. However, a correct comparison of the methods will not be possible, until their careful assessment in the same patients is performed. In addition, a final statement today should consider also the increasing need to carry out an economic analysis by evaluating the cost-effectiveness of the examinations.

Breast cancer seeking agents: basic approach.

The knowledge of biochemical and physiological mechanisms involved in tissue localization is important so as to understand the information given by diagnostic nuclear medicine imaging, and eventually to design new radiopharmaceuticals. The cellular mechanisms which permit a high cancer uptake involve the perfusion and metabolism around the tumour tissue, the interference with normal function, the altered perfusion and/or metabolism within the tumour. All these phenomena can contribute to a high concentration of particular radiotracers in cancer and can create a favourable tumour/background ratio uptake sufficient for cancer imaging. Those molecules might be also powerful tools for reaching an advanced understanding of neoplastic and even "normal" cell biology. During these last years, some radiotracer specifically designed for different applications proved to be promising radiopharmaceuticals for breast cancer imaging. This is the case of monoclonal antibodies (Mabs) developed in the past against membrane cancer antigens. Other tracers, originally proposed for the study of vascular perfusion (cardiovascular tracers), have also revealed a capacity to be taken up by cancer cells. The radiopharmaceuticals mostly used as tumour seeking agents today (Radiothallium, Sestamibi, Tetrophosmin) were generated with other applications in mind. In this paper we review the mechanisms of uptake of the most relevant agents currently proposed for breast cancer imaging, including 18F-fluorodeoxyglucose (FDG). The radiotracers will be examined on the basis of the available scientific evidence regarding their cellular uptake and release. Moreover, we report our preliminary studies on the cellular uptake and release of these and other compounds recently introduced in clinical trials.