A systematic review about the role of preoperative 18F-FDG PET/CT for prognosis and risk stratification in patients with endometrial cancer.

OBJECTIVE: To analyse the available literature on the prognostic value of preoperative 18F-FDG PET/CT metabolic parameters and their usefulness in risk stratification in patients with endometrial cancer (EC). MATERIAL AND METHODS: Pubmed searches used "(endometr* OR uter*) AND (PET OR FDG)" as keywords from January-2000 to June-2020. References in included articles were checked for possible publications not included in the first search. Studies evaluating the prognostic value of preoperative 18F-FDG PET/CT and its role for risk stratification in patients with EC were included. Non-original articles (reviews, editorials, letters, legal cases, interviews, case reports, etc.) were not included. RESULTS: Twenty-six studies (1918 patients) were selected according to the inclusion criteria in this review. Thirteen studies (939 patients) related to the prognostic role of preoperative 18F-FDG PET/CT and 14 studies (1036 patients) related to its role in risk stratification were included. Parameters such as SUVmax, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were analysed. CONCLUSIONS: Preoperative SUVmax is useful for non-invasive diagnosis and for deciding the appropriate therapeutic strategy, as it could be used as an independent prognostic marker for recurrence and survival in EC. In addition, both preoperative VTM and GTL could be independent prognostic factors for predicting recurrence and survival, but there is still insufficient scientific evidence. The usefulness of SUVmax for risk stratification is limited (there is insufficient literature that 18F-FDG PET/CT can replace surgical staging), although VTM and GTL are more accurate and have a valuable role in risk stratification of EC. However, larger multicentre studies with adequate follow-up time are needed to confirm these findings.

Role of 99mTc-HYNIC-Tyr3-octreotide scintigraphy in neuroendocrine tumors based on localization of the primary tumor.

BACKGROUND: The aim of our work was to determine the accuracy of 99mTc-HYNIC Tyr3 octreotide scintigraphy (TcOS) in detecting active disease in neuroendocrine tumors (NETs) based on embryological origin of the primary tumor (foregut, midgut or hindgut). METHODS: We analyzed retrospectively 45 studies (12 staging, 26 suspicion of recurrence, and 7 treatment response) belonging to 33 patients with histological confirmation of NETs. Whole body scan and a SPECT-CT were acquired 4 hours post-injection of 740 MBq of 99mTc-HYNIC Tyr3 octreotide. The studies were divided into 3 groups based on the embryological origin of primary tumor (foregut [group 1], midgut [group 2] and hindgut [group 3]). The accuracy of TcOS in each group was assessed, included chi-square analyses. The final diagnosis was established by histopathology or clinical/radiological follow-up greater than 6 months. RESULTS: The localization of the primary tumor per patient revealed that 58% were from the foregut, 30% from the midgut and 12% from the hindgut. In study-based analysis (45 studies), TcOS showed an overall sensitivity, specificity and accuracy of 95%, 92% and 93% respectively. The accuracy per studies for the groups 1, 2 and 3 were: 100%, 92% and 66% respectively, demonstrating a better detection of active disease in primary tumors from foregut and midgut compared to hindgut (P=0.02). CONCLUSIONS: The accuracy of TcOS in the assessment of NETs seems to be better in tumors with foregut and midgut origin, showing a possible relationship between the embryological origin of NETs and detection of active disease by TcOS.