(68)Ga-PSMA PET/CT for restaging recurrent prostate cancer: which factors are associated with PET/CT detection rate?

PURPOSE: To assess the association between PSA levels, PSA kinetics and other factors and a pathological (68)Ga-PSMA PET/CT scan in patients with recurrent prostate cancer (rPCa) with biochemical relapse (BR) after radical therapy. METHODS: Seventy consecutive rPCA patients referred for (68)Ga-PSMA PET/CT, matching all the following criteria, were retrospectively evaluated: (a) previous radical prostatectomy or primary radiotherapy with curative intent; (b) BR or persisting high PSA levels after primary treatment; and (c) complete clinical and imaging information. The mean\u2009\ub1\u2009SD PSA level was 3.5\u2009\ub1\u20095.3 ng/mL (median 1.7, range 0.2 - 32.2 ng/mL), the mean\u2009\ub1\u2009SD PSA doubling time (PSAdt) was 6.5\u2009\ub1\u20095.5 months (median 5.5, range 1.3 - 31.6 months), and the mean\u2009\ub1\u2009SD PSA velocity was 7.9\u2009\ub1\u200920.5 (median 2.1, range 0.2 - 147.5 ng/mL/year). Statistical analysis was performed to assess which factors were associated with the detection of rPCa on (68)Ga-PSMA PET/CT. RESULTS: (68)Ga-PSMA PET/CT was positive in 52 of 70 patients (74.2%). In 30 patients (42.8%) lesions limited to the pelvis were detected. Distant lesions were observed in 8 of patients (11.4%). Local plus systemic lesions were detected in 14 patients (20%). PSA level (p\u2009=\u20090.017) and PSAdt (p\u2009=\u20090.0001) were significantly different between PET-positive patients (higher PSA level, shorter PSAdt) and PET-negative patients (lower PSA, longer PSAdt). ROC analysis showed that PSAdt 6.5 months and PSA 0.83 ng/mL were optimal cut-off values. In multivariate analysis PSAdt was associated with (68)Ga-PSMA PET/CT positivity. (68)Ga-PSMA PET/CT was positive in 17 of 20 patients (85%) with PSA <2 ng/mL and PSAdt <6.5 months, and in 3 of 16 patients (18.7%) with PSA <2 ng/mL and PSAdt 656.5 months. CONCLUSION: The great potential of (68)Ga-PSMA PET/CT in patients with rPCa and BR was confirmed. PSA and PSAdt were valuable predictors of pathological (68)Ga-PSMA PET/CT findings

Consensus document on the progression and treatment response criteria in gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead to tumor shrinkage. Thus, evaluation of the therapeutic response should differ from other kind of tumors. To answer relevant questions about which techniques are best in the assessment of progression or treatment response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by a systematic search of the literature. The expert panel answered all questions with recommendations, combining available evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting. Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best way to evaluate treatment response were formulated

Guideline for PET/CT imaging of neuroendocrine neoplasms with 68Ga-DOTA-conjugated somatostatin receptor targeting peptides and 18F–DOPA

Purpose & Methods Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using Ga-68-DOTA-conjugated peptides, as well as F-18-DOPA imaging for various neuroendocrine neoplasms. Results & Conclusion The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with Ga-68-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts.Wo