In this preliminary report, we explore the uptake pattern of fluorodeoxyglucose (FDG) in fibromatosis and hypothesize the potential clinical role of FDG-positron emission tomography (PET) in the management of this benign but locally aggressive heterogeneous group of soft-tissue tumours. Five patients were studied (two men and three women, age range 23–35 years), among whom were three cases of deep musculoskeletal fibromatosis, one of abdominal fibromatosis (abdominal desmoid) associated with familial adenomatous polyposis (Gardner's syndrome) and one case of both deep musculoskeletal fibromatosis and abdominal desmoid. The FDG uptake in the lesions was heterogeneous in four cases and relatively homogeneous in one case. The uptake ranged from low to moderate grade with areas or foci of relatively avid FDG uptake. The maximum standardized uptake value (SUVmax) observed was up to 4.7; the avidity probably related to the biological aggressiveness and tendency for recurrence, characteristic of fibromatosis. A ...

Peptide receptor radionuclide therapy (PRRT), over the years, has evolved as an important modality in the therapeutic armamentarium of advanced, metastatic or inoperable, progressive Neuroendocrine Neoplasms (NENs). This review deliberates on the basic understanding and applied clinical aspects of PRRT in NENs, with special reference to (1) tumor biology and receptor characteristics, (2) molecular PET-CT imaging (in particular the invaluable role of dual-tracer PET with [⁶⁸Ga]-DOTA-TATE/NOC and [¹⁸F]-FDG for exploring tumor biology in continuum and individualizing treatment decision making) and NEN theranostics, (3) relevant radiochemistry of different therapeutic radionuclides (both beta emitting ¹⁷⁷Lu-DOTATATE and ⁹⁰Y-DOTATATE and alpha emitting ²²⁵Ac-DOTATATE), and (4) related dosimetric considerations. Successful clinical management of the NENs would require multifactorial considerations, and all the aforementioned points pertaining to the disease process and available logistics are key considerations for state-of-the-art clinical practice and delivering personalized care in this group of patients. Emphasis has been placed on relatively intriguing areas such as (1) NET grade 3 of WHO 2017 classification (ie, Ki-67>20% but well-differentiation features), (2) “Neoadjuvant PRRT,” (3) combining chemotherapy and PRRT, (4) ‘Sandwich Chemo-PRRT’, (5) duo-PRRT and tandem PRRT, (6) resistant functioning disease with nuances in clinical management and how one can advocate PRRT rationally in such clinical settings and individualize the management in a patient specific manner. Relevant clinical management issues related to some difficult case scenarios, which the Nuclear Medicine attending physician should be aware of to run an efficient clinical PRRT services, are described.

Objective: To evaluate the therapeutic response, progression free survival (PFS), overall survival (OS) and clinical toxicity of 177Lu-PSMA-617 PSMA targeted radioligand therapy (PRLT) in the setting of heavily pre-treated metastatic castrate-resistant prostate cancer (mCPRC) patients and also examine the association of prognostic variables with therapeutic outcome in such patient cohort. Methods: We examined the medical records of mCRPC patients who had undergone 177Lu-PSMA-617 PRLT from March 2017 to February 2019 in our institute. Patients receiving equal to or more than two cycles were included and analyzed in this retroprospective study.The 68Ga-PSMA-11 PET-CT and 18-fludeoxyglucose positron emission tomography (18FDG PET)-CT scan findings, serum prostate-specific antigen (PSA) change, health-related quality of life (HRQoL) scales (Eastern Cooperative Oncology Group/Karnofsky score) and Gleason score were assessed for their implications on the outcome of therapy. The treatment response was evaluated under three categories: (a) symptomatic (b) biochemical and (c) imaging response.The PFS and OS following first PRLT were determined and the association of various variables with PSA doubling time (DT) and FDG uptake in the lesions were analyzed. Toxicity assessment was undertaken objectively by National Cancer Institute-Common Terminology Criteria for Adverse Events scale v. 5.0 for haematological and nephrotoxicity, and salivary gland toxicity assessed by xerostomia inventory score. Results: A total of 40 mCRPC patients (age range: 46–84 years; median 63 years), who had undergone 177Lu-PSMA-617 PRLT, of at least two cycles was identified and selected for the analysis. FDG uptake was noted in 87.5% of patients (n = 35). Out of 40 cases, 21 were responders (CR, PR and SD) and 19 were non-responders (PD) on symptomatic and biochemical scales while on molecular imaging response, 16 (43%) were responders and remaining 21 (57%) were non-responders. Lesion-wise, 68Ga-PSMA-11 avid metastatic nodal disease responded well with 177Lu PSMA-617 PRLT, as compared to hepatic and skeletal lesions. The median OS and PFS was 12 and 7 months respectively following first PRLT. Patients with negative serum PSA-DT demonstrated superior 1 year PFS as compared to those with positive serum PSA-DT (52.5 vs 47.5%) (p = 0.029). Patients receiving greater than two cycles PRLT demonstrated a higher negative PSA-DT as compared to those receiving two cycles (p-value = 0.03). Grade 1 xerostomia was observed in two patients (5%) (mean xerostomia score of 23), haematotoxicity in seven patients [Grade I (n = 2, 5%) and Grade II (n = 5, 14%)]. Conclusion: 177Lu-PSMA-617 PRLT was well-tolerated and able to produce disease control with good symptomatic and biochemical responses in the context of heavily pre-treated mCRPC with progressive disease, with low toxicity profile. Evident association of high FDG uptake was observed with aggressive disease biology coupled with increasing Gleason score and poorer 12 months PFS. Negative PSA-DT following therapy demonstrated longer PFS. The results demonstrate important future role of 177Lu-PSMA-617 PRLT in the treatment of mCRPC. Advances in knowledge: The present work explored in a large teriary cancer care setting, the efficacy of 177Lu-PSMA-617 PRLT, in an aggressive and unselected subset of mCRPC. The response and outcome was correlated with a number of prognostic variables, including molecular imaging findings (FDG uptake in the metastatic lesions), PSA DT and Gleason score.

OBJECTIVE: The aim of the study was to assess ¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) in neoadjuvant setting in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). In addition, we also evaluated the variables associated with resectability of the primary following PRRT. MATERIALS AND METHODS: A total of 57 GEP-NETs with unresectable primary due to vascular involvement as defined using the National Comprehensive Cancer Network (NCCN) criteria given for pancreatic ductal adenocarcinoma (PDAC), who underwent ¹⁷⁷Lu-DOTATATE without any prior surgery were included in this study. GEP-NETs were divided into two groups: Group1-without liver metastases (n = 23 patients) and Group2- with potentially resectable liver metastases (n = 34 patients). ¹⁷⁷Lu-DOTATATE was administered with mixed amino acid-based renal protection with dose of 7.4 GBq (200 mCi) per cycle. Evaluation of surgical resectability following PRRT was done by using tri-phasic computed tomography (CT) imaging. Overall PRRT response was evaluated under four broad categories. The Kaplan–Meier product-limit method was used to calculate progression free survival (PFS) and overall survival (OS). Associations between variables and resectable primary after PRRT were analyzed by using Chi-square test at significant P value less than 0.05. RESULTS: Following ¹⁷⁷Lu-DOTATATE, unresectable primary became resectable in 15 out of 57 (26.3%) patients {7 patients in group-1 and 8 patients in group-2}. Response (complete response and partial response) to PRRT was seen in 48 patients (84%), 23 patients (40%), 18 patients (31%) and 23 patients (40%) on symptomatic, biochemical, molecular imaging and anatomical imaging response evaluation criteria respectively. Estimated rates of PFS were 95% and 90% at 2 years in group1 and group2 patients respectively. The 2-years OS of combined both groups was 92.1%. Higher rate of resectable primary following PRRT was found in duodenal NET, GEP-NETs with absent regional lymph node involvement, size of primary<5cm, size of liver lesions ≤1.5 cm, number of liver lesions ≤3 and FDG uptake(SUV_max<5 in primary tumor) with significant P value. CONCLUSION: Thus, unresectable primary converted could be into resectable in a moderate fraction of GEP-NETs following ¹⁷⁷Lu-DOTATATE, signifying that neoadjuvant PRRT could be considered in GEP-NETs patients with unresectable primary due to vascular involvement with or without liver metastases. Effective control of symptoms with favorable morphological and functional imaging response and durable PFS and OS following ¹⁷⁷Lu-DOTATATE PRRT were important observation in our study, which may lead to less morbidity and mortality in these patients.