Technical note: A preliminary comparative study between classical and interventional radiological approaches for multi-phase post-mortem CT angiography.

Multi-phase post-mortem computed tomography angiography (MPMCTA) is a new diagnostic tool, used in forensic pathology. On the one hand, this technique allows a better and direct visualization of vascular and solid organ lesions. On the other hand, the invasiveness of the procedure-which requires surgical denudation (inguinal and/or cervical) and the insertion of surgical cannulas-leads to many relatives refusing scientific autopsies. Our hypothesis states that a minimally-invasive procedure combining interventional radiological techniques with MPMCTA (replacement of surgical cannulas by radiological catheters) will improve the approval rate of scientific autopsies by families. The aim of this study was to evaluate the feasibility of the minimally-invasive MPMCTA approach and to compare its performance to the current reference-standard (the conventional approach). We included consecutively 16 corpses divided in two groups according to the contrast enhancement approach: radiological catheters (n=8), and surgical cannulas (n=8). Corpses were chosen and assigned randomly from our local data. The quality of the imaging procedure was compared according to four items: global vascular opacification, cerebral venous opacification, and lower limbs opacification (arterial and venous). A minimally-invasive approach for scientific autopsies is feasible through a radiological catheter. Vascular opacification was optimal in 8 out of 8 cases and was no less effective than the control reference group using surgical cannula incision associated with their non-occlusive aspects

Prognostic 18F-FDG PET biomarkers in metastatic mucosal and cutaneous melanoma treated with immune checkpoint inhibitors targeting PD-1 and CTLA-4.

To compare the prognostic value of imaging biomarkers derived from a quantitative analysis of baseline 18F-FDG-PET/CT in patients with mucosal melanoma (Muc-M) or cutaneous melanoma (Cut-M) treated with immune checkpoint inhibitors (ICIs). In this retrospective monocentric study, we included 56 patients with non-resectable Muc-M (n = 24) or Cut-M (n = 32) who underwent baseline 18F-FDG-PET/CT before treatment with ICIs between 2011 and 2017. Parameters were extracted from (i) tumoral tissues: SUVmax, SUVmean, TMTV (total metabolic tumor volume), and TLG (total lesion glycolysis) and (ii) lymphoid tissues: BLR (bone marrow-to-liver SUVmax ratio) and SLR (spleen-to-liver SUVmax ratio). Association with survival and response was evaluated using Cox prediction models, Student's t tests, and Spearman's correlation respectively. p < 0.05 was considered significant. Majority of ICIs were anti-PD1 (92.9%, n = 52/56). All 18F-FDG-PET/CT were positive. Overall (Muc-M to Cut-M), ORR was 33%:42%, DCR was 56%:69%, median follow-up was 25.0:28.9 months, median PFS was 4.7:10.7 months, and median OS was 23.9:28.3 months. In Muc-M, increased tumor SUVmax was associated with shorter OS while it was not correlated with PFS, ORR, or DCR. In Cut-M, increased TMTV and increased BLR were independently associated with shorter OS, shorter PFS, and lower response (ORR, DCR). While all Muc-M and Cut-M were FDG avid, prognostic imaging biomarkers differed. For Muc-M patients treated with ICI, the only prognostic imaging biomarker was a high baseline maximal glycolytic activity (SUVmax), whereas for Cut-M patients, baseline metabolic tumor burden or bone marrow metabolism was negatively correlated to ICI response duration