Correlation between pre-radical prostatectomy standardized SUVmax ratios detected on 68Ga-PSMA-I&T PET/CT and final histopathology outcomes: an in-depth analysis.

OBJECTIVE: To evaluate the predictive potential of the maximum standardized uptake value(SUVmax) value of intraprostatic tumors derived from preoperative 68Ga-PSMA-I&T PET/CT (SUVT), and its ratios to SUVmax in the liver (SUVTLR) and parotid gland (SUVTPR) with respect to histopathological findings. MATERIALS AND METHODS: Data from patients who underwent radical prostatectomy (RP) for prostate cancer (PC) at our clinic between 2017 and 2020 were assessed. Patients with a secondary malignancy, a history of transurethral prostate resection, prior treatment for PC, or who received salvage RP were excluded. Whole-body images obtained using the same device, as per the guidelines, were reviewed by two nuclear medicine specialists with more than a decade of experience to reach a consensus for each lesion. The relationships between age, PSA, Prostate Volume, clinical T stage, biopsy International Society of Urological Pathology grade (ISUP), D'amico risk group, intraprostatic tumor volume (HPTV) identified in the final histopathological specimen review, HP-ISUP grade, seminal vesicle invasion (SVI), extracapsular invasion (ECI), positive surgical margine (PSM), SUVT, SUVTLR, and SUVTPR were analyzed. RESULTS: The mean age of the 64 included patients was 64.1 ±â€¯5.3. A statistically significant correlation was found between SUVT, SUVTLR, SUVTPR values, and histopathologic stage parameters, such as biopsy ISUP, D'amico Risk Classification, HP-ISUP, HPTV (p < 0.05). PSMATV, SUVT, and SUVTLR were statistically significant predictors of extracapsular invasion, while PSA, PSMATV, and SUVTLR were significant predictors of SVI (p < 0.05). CONCLUSION: The standardized SUVT, SUVTLR, and SUVTPR values could be employed as noninvasive markers to assist in predicting postoperative histopathological findings, particularly ECI, SVI, and PSM.

An automated synthesis of 177Lu-EDTMP as an efficient bone-seeking therapeutic radiopharmaceutical.

OBJECTIVE: Radiolabeled bisphosphonates have found wide clinical use in nuclear medicine for palliative therapy of bone metastases. 177Lu-EDTMP was used to relieve metastatic bone pain in patients with breast or prostate cancer. The therapeutic efficacy of 177Lu-EDTMP at 1-, 3-, 6-, and 8-weeks post-therapy was evaluated using Standard Pain Scoring Assessment Criteria. In addition, toxicity was evaluated in terms of hematological parameters using the Common Terminology Criteria for Adverse Events V4.0. PATIENTS AND METHODS: A fully automated synthesis of 177Lu-EDTMP was achieved in this study with high radiochemical efficiency and high radiochemical purity. During the study, 75 patients (57 M: 18 F, mean age: 68.0 ± 11.1 years) of breast/prostate cancer with documented skeletal metastases were included. Patients were administered intravenously with 177Lu-EDTMP at a dose rate of 22.2-37.0 MBq/kg following a fully automated synthesis of 177Lu-EDTMP using a disposable cassette system. RESULTS: Among the 75 patients all treated with 177Lu-EDTMP, 59 patients were responsive and the remaining 16 patients did not respond to the therapy. Mean pain score values in the responder group were 5.60 ± 0.5, 4.3 ± 0.1, 2.6 ± 0.4 and 1.4 ± 0.7 at weeks 1, 3, 6, and 8, respectively. Also, the mean pain score decreased from a baseline score of 7.6 ± 1.6 to 1.4 ± 0.7 at week 8 in the responder group. Statistical analysis of the pain score data showed a significant decrease in pain score after each radiopharmaceutical treatment, compared to the baseline scores (p <0.0001). Mild to severe toxicity was observed in two patients each treated with 177Lu-EDTMP. CONCLUSIONS: These findings demonstrated that the 177Lu-EDTMP radiopharmaceutical could be used safely to achieve considerable therapeutic efficacy, in metastatic bone pain palliation together with the safe clinical application and low radiation exposure during preparation.

Serum calprotectin: a new potential biomarker for thyroid papillary carcinoma.

The aim of this study was to evaluate serum calprotectin levels and oxidative stress status in patients with papillary thyroid carcinoma (PTC) and the changes in their levels after total thyroidectomy. The study involved 30 patients with PTC and 30 healthy controls. Blood samples were obtained from the PTC patients before and 1 month after the operation. Preoperative and postoperative serum samples from PTC patients and healthy controls were analysed for calprotectin, total antioxidant status (TAS), total oxidant status (TOS) and lipid hydroperokside (LOOH). The preoperative calprotectin, TOS, OSI and LOOH levels of the patients with PTC were significantly higher compared to those of the control group (p < 0.001, for each). The levels of calprotectin decreased significantly in patients with PTC after the operation (p < 0.001), while TAS, TOS and OSI levels remained unchanged (p = 0.313, p = 0.085 and p = 0.163, respectively). Preoperative serum calprotectin levels were positively correlated with TOS, OSI and LOOH levels and negatively correlated with TAS levels in patients with PTC. In conclusion, serum calprotectin levels is increased in patients with PTC, and calprotectin is positively correlated with TOS and LOOH. Serum calprotectin levels is significantly decreased after total thyroidectomy.

F-18 FDG PET/CT imaging in the diagnostic work-up of thyroid cancer patients with high serum thyroglobulin, negative I-131 whole body scan and suppressed thyrotropin: 8-year experience.

OBJECTIVE: Fluorodeoxyglucose positron emission tomography/computed tomography imaging in the follow-up of patients with differentiated thyroid carcinoma who have high serum thyroglobulin, negative iodine-131 whole body scan and suppressed thyrotropin. PATIENTS AND METHODS: A total of 90 patients (31 male and 59 female) with differentiated thyroid carcinoma who have high serum thyroglobulin and negative iodine-131 whole body scan were included in the study between July 2006 and March 2014. All patients had undergone surgery (total thyroidectomy ± lymph node dissection) followed by iodine-131 ablation. Of the patients, 82 had papillary thyroid carcinoma and 8 follicular thyroid carcinoma. Serum thyrotropin was suppressed (< 2 µ IU/ml) during the Fluor-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging procedure. RESULTS: The overall sensitivity of fluor-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in the detection of metastasis of differentiated thyroid cancer was 84.8%, the specificity 79.1%, respectively. The sensitivity and specificity of fluor-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in classic type of papillary cancer was 83.3% and 54.5%, respectively. The corresponding figures for the tall cell variant was 85.7% and 87.5%, respectively. The difference between the two histological subtypes was statistically significant (p < 0.05). CONCLUSIONS: Our results suggest that fluor-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging could be a valuable test for the routine follow-up of patients with differentiated thyroid carcinoma.

Gastric gastrointestinal stromal tumor with bone metastases - case report and review of the literature.

Gastrointestinal stromal tumors (GISTs) represent rather rare neoplasms. Most GISTs are benign; malignant tumors account for 20- 30% of cases (overall, approximately 10- 30% of GISTs exhibit malignant behavior). GISTs most commonly metastasize to the liver and abdominal cavity. Distant metastases to other sites, especially to the bones, are relatively rare. We report a case of a 62 year  old man with metastatic spread of GIST to skull, ribs and both sacroiliac joints manifesting six months after surgical resection of a gastric tumor. Although bone metastases from GISTs are rare and there are only a few reported cases in the literature, this case emphasizes that metastatic disease should always be considered in a patient with gastric GIST and suspicious bone lesions.

The role of FDG PET-CT in differential diagnosis of pleural pathologies.

OBJECTIVE: This study has aimed to evaluate the impact of (F18) Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) in the differential diagnosis of malignant and benign pleural lesions in patients with suspected malignant pleural mesothelioma (MPM). MATERIAL AND METHODS: Fifty patients (32 females, 18 males; age range 24-79 years) with pleural thickening, fluid, plaques or calcification on previous CT scan were examined with FDG PET-CT. PET-CT imaging was obtained 1 h after FDG injection. In 12 patients, delayed imaging from the thoracic region was performed 2 h after injection. FDG uptake was evaluated visually and semiquantitively using standardized uptake value (SUV). FDG PET-CT findings were compared with histopathologic diagnosis. RESULTS: Thirty-nine patients had increased FDG uptake in pleural lesions but PET-CT results were negative in 11 patients. When compared with histopathological results in FDG positive group, 34 patients had MPM, 5 had benign pathology; in FDG negative group 8 patients had benign pathology, 3 had MPM. Of patients with delayed imaging, 9 showed increased SUV but 3 had a decreased SUV on delayed images. Increased SUV group had 4 MPM, 5 benign pathology (3 chronic granulomatous inflammation, 2 benign asbestotic plaque). Decreased SUV group all had benign pathology (fibrosis, chronic inflammation, myofibrosis). DISCUSSION: FDG PET-CT is a useful imaging modality in differential diagnosis of malignant and benign pleural lesions. Delayed imaging seems to be useful if there is a decrease in SUV suggesting a benign pathology but does not seem to contribute to the differential diagnosis if the SUV is increased.

Lung metastases in patients with differentiated thyroid carcinoma and evaluation of response to radioiodine therapy.

INTRODUCTION: The most common site of metastases in differentiated thyroid carcinomas is the lungs. In our study, we aimed to determine the ratios of lung metastases in patients with differentiated thyroid carcinoma and response to radioiodine therapy. MATERIAL AND METHODS: A total of 542 patients with differentiated thyroid carcinoma who were admitted to our clinic were included in the study. High doses of (131)I were administered to the patients with lung metastases. Response to therapy were evaluated with (131)I scans and stimulated serum Tg levels were examined at least 6 months after therapy. RESULTS: Lung metastases were detected in 17 (3.1%) of 542 patients with differentiated thyroid carcinoma. Of these patients to whom high doses of (131)I therapy were administered, complete response to therapy was obtained in 5 (29.4%), partial response was obtained in 3 (17.6%) and no response could be obtained in 9 (53%) patients. CONCLUSION: Although lung metastases from differentiated thyroid carcinomas are rare, those are more common in advanced ages and in males. High doses of (131)I therapy may be partially beneficial in these patients. Thus repetition of therapy is frequently required.

FDG PET/CT appearance of multicentric Castleman's disease mimicking lymphoma.

We report a case of a multicentric form of Castleman's disease with multiple lymph nodes showing intense FDG uptake on whole body scan mimicking non-Hodgkin's lymphoma. In this report, the patient had multiple cervical, mediastinal, hilar, retroperitoneal and abnormal lymph nodes in the groin. (18)F-fluorodeoxyglucose positron emission tomography/computed tomography was performed before tissue sampling. (18)F-FDG/PET demonstrated multiple areas of increased uptake in cervical, mediastinal, hilar, retroperitoneal and groin lymph nodes, suggesting a generalized disease of the lymphatic system including non-Hodgkin's lymphoma. The final diagnosis is based on the histopathological findings of the material obtained from the cervical lymphadenectomy. The histological diagnosis was multicentric plasma cell variant of Castleman's disease. (18)F fluorodeoxyglucose positron emission tomography/computed tomography scan helped to identify the lymph nodes involved throughout the whole body, but did not help to differentiate non-Hodgkin's lymphoma. The clinical conclusions and PET/CT findings are described in this report.