Despite vast worldwide experience in the use of 131I for treating Graves' disease (GD), no consensus of opinion exists concerning the optimal method of dose calculation. In one of the most popular equations, the administered (131)I dose is directly proportional to the estimated thyroid gland volume and inversely proportional to the measured 24-hour radioiodine uptake. In this study, we compared the efficiency of different tissue-absorbed doses to induce euthyroidism or hypothyroidism within 1 year after radioiodine therapy in GD patients. The study was carried out in 134 GD patients (age, 53 +/- 14 year; range, 16-82 year; thyroid volume, 28 +/- 18 mL; range, 6-95 mL; average 24-hour thyroid uptake, 72%) treated with (131)I therapy. The average radioiodine activity administered to patients was 518 +/- 226 MBq (range, 111-1110). The corresponding average thyroid absorbed dose, calculated by a modified Medical Internal Radiation Dose (MIRD) equation was 376 +/- 258 Gy (range, 99-1683). One year after treatment, 58 patients (43%) were hypothyroid, 57 patients (43%) were euthyroid, and 19 patients (14%) remained hyperthyroid. The patients were divided into 3 groups: 150 Gy (n = 32), 300 Gy (n = 58) and >300 Gy (n = 44). No significant difference in the rate of recurrent hyperthyroidism was found among the 3 groups (150 Gy: 15%; 300 Gy: 14%; and > or =300 Gy: 14%; chi-square test, p = 0.72). Whereas, the rate of hypothyroidism in the 3 groups was significantly correlated with the dose (150 Gy: 30%; 300 Gy: 46%; >300 Gy: 71%; chi-square test, p = 0.0003). The results obtained in this study show no correlation between dose and outcome of radioiodine therapy (in terms of persistent hyperthyroidism) for thyroid absorbed doses > or =150 Gy, while confirming the relation between the thyroid absorbed dose and the incidence of hypothyroidism in GD patients.

The aim of this study was to optimize a protocol for radioguided biopsy of the sentinel lymph node (SLN) in patients with melanoma. The protocol was based on a combination of ex vivo counting of the nodes detected intraoperatively and analysis of the harvested nodes by hematoxylin and eosin staining plus immunohistochemistry (conventional histopathology [PATH]) and by molecular biology (reverse-transcriptase polymerase chain reaction [RT-PCR]). Methods: A total of 124 patients with primary clinical stage I-II (according to the American Joint Committee on Cancer) cutaneous melanoma underwent successful radioguided SLN biopsy. SLNs harvested for analysis included any additional nodes whose ex vivo counting rate exceeded 20% of the hottest node. All removed SLNs were examined by conventional PATH and with RT-PCR analysis for the expression of messenger RNA for tyrosinase and the melanoma antigens recognized by T cells. Complete lymph node dissection (CLND) was performed only in the case of SLN metastasis detected by PATH. Different combinations of the intraoperative parameters (only the hottest node and all nodes harvested) and of analysis (PATH and RT-PCR) were tested as predictors of clinical outcome on the basis of long-term follow-up (12-81 mo; median, 55 mo). Results: A total of 197 SLNs were harvested, 41 of which harbored metastasis as detected by RT-PCR analysis; PATH detected metastasis in only 24 of 41 metastatic SLNs. In 5 of 41 instances, metastasis was not in the hottest SLN. The main factor determining correct classification of the SLN status was RT-PCR, which significantly improved detection of metastasis, even if applied only to the hottest node (P , 0.0001 vs. PATH analysis of either the hottest SLN or all nodes above the 20% threshold). Metastatic disease recurred locally in 5 patients who had not undergone CLND; RT-PCR analysis showed metastasis in 4 of these patients. The false-negative rate of SLN biopsy progressively decreased when applying PATH only to the hottest node (32.1%), additional RT-PCR to the hottest node (21.4%), PATH to all nodes (17.9%), and RT-PCR to all nodes (3.6%, P 5 0.015 vs. PATH analysis of only the hottest SLN). Conclusion: On the basis of long-term follow-up (the gold standard for final clinical outcome of SLN biopsy), both 20% threshold and RT-PCR analysis should be applied for optimal detection of nodal metastases in patients with melanoma.

The role of nuclear medicine physicians in the multidisciplinary team for the management of patients with prostate cancer has been restricted because of a lack of available tools. The only drugs approved to relieve pain related to bone metastases were β-emitting radiopharmaceuticals. These drugs did not prove to prolong survival when used as single agent and resulted associated with important adverse events. This situation has changed with the introduction of radium 223 because of evidence of improved survival in patients, the good safety profile and the opportunity to avoid clonal selection of tumor cells. Cooperation among physicians involved in cancer management will lead to improvements in the treatment of bone metastases due to prostate cancer and is thought to extend to other tumor types. KeywordsThe management of most prostate cancer cases involves committed specialists such as urologists, medical oncologists, radiotherapists, and nuclear medicine physicians. Evidence shows that in men with high-risk prostate cancer, only a patient-focused program based on a multidisciplinary approach can result in improved survival [1]. The role of nuclear medicine physicians in this multidisciplinary team so far has been restricted to providing pain relief. In castration-resistant prostate cancer (CRPC) patients with bone metastases (mCRPC), radiopharmaceuticals turned out to be useful only for noncurative purposes, exclusively aiming at improving symptomatic pain control. In addition, the available drugs have induced considerable serious adverse events, mostly hematologic, and thus have prevented subsequent therapeutic approaches [2]. Therefore, radionuclide-based therapy for symptomatic bone metastases has remained underused and limited to the late phases of the disease [3].The lack of safe therapeutic approaches to extend survival in CRPC patients has been a challenge for nuclear medicine physicians accustomed to successfully treating other tumor types, such as thyroid tumors with radioiodine therapy, or treating hematologic malignancies with ibritumomab tiuxetan. The recent introduction of the radiopharmaceutical radium Ra 223 (Ra 223) dichloride represents a breakthrough because, for the first time, an impact of a radiopharmaceutical on survival of patients with bone metastases due to prostate cancer was demonstrated in a large Phase III trial [4]. This drug, in fact, received the category 1 recommendation as first-line and second-line option by National Comprehensive Cancer Network (NCCN) guideline similarly to chemotherapy [5], and thus the nuclear medicine physician assumed a key position in the current multidisciplinary team for the treatment of mCRPC. The team should evaluate which patients are suitable for Ra 223 dichloride without limiting access to patients in the terminal stages of the disease and should integrate the nuclear medicine physician into the team with the medical oncologist and surgeon. Future Oncol. (Epub ahead of print)

Prior administration of Sm-EDTMP does not cause additional toxicities for subsequent treatment with docetaxel and does not reduce the antitumor efficacy of the latter. This work justifies further investigations on the possible synergistic effects of combined strategies with the two agents.

Neuropathological and clinical evidence indicates that the clinical expression of Alzheimer's disease (AD) occurs as neuropathology exceeds the brain reserve capacity. The brain or cognitive reserve (BCR) hypothesis states that high premorbid intelligence, education, and an active and stimulating lifestyle provide reserve capacity, which acts as a buffer against the cognitive deficits due to accumulating neuropathology. Neuroimaging studies that assessed the BCR hypothesis are critically reviewed with emphasis on study design and statistical analysis. Many studies were performed in the last two decades owing to the increasing availability of positron emission tomography (PET) and PET/computed tomography scanners and to the synthesis of new radiopharmaceuticals, including tracers for amyloid and tau proteins. Studies with different tracers provided complementary consistent results supporting the BCR hypothesis. Many studies were appropriately designed with a measure of reserve, a measure of brain anatomy/function/neuropathology, and a measure of cognitive functions that are necessary. Most of the early studies were performed with PET and [ 18F]fluorodeoxyglucose, and occasionally with [ 15O]water, reporting a significant association between higher occupation/education and lower glucose metabolism (blood flow) in associative temporo‐parietal cortex in patients with AD and also in patients with MCI, after correcting for the degree in the cognitive impairment. On the contrary, performances on several neuropsychological tests increased with increasing education for participants with elevated [ 11C]PiB uptake. Studies with the tracers specific for tau protein showed that patients with AD with elevated tau deposits had higher cognitive performances compared with patients with similar levels of tau deposits. BCR in AD is also associated with a preserved cholinergic function. The BCR hypothesis has been validated with methodologically sound study designs and sophisticated neuroimaging techniques using different radiotracers and providing an explanation for neuropathological and clinical observations on patients with AD.