To the Editor We congratulate Perri et al for publishing the comparative analysis of fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) vs gemcitabine and nab-paclitaxel chemotherapy for localized pancreatic adenocarcinoma (PDAC).1
Perri et al have assessed the response rates by the modified Response Evaluation Criteria in Solid Tumours, version 1.1, and tumor volumetric analysis with a unique ellipsoid formula: Volume = π / (6 × L × W × H), where L indicates the longest axial diameter; W, shortest axial diameter; and H, craniocaudal diameter.