Metabolic tumour volume of anal carcinoma on 18FDG PET/CT before combined radiochemotherapy is the only independant determinant of recurrence free survival

Aim: to determine whether [F-18]2-fluoro-2-deoxyglucose (FDG) positron emission tomography and X-ray computed tomography (PET/CT) findings and metabolic parameters before combined chemo- and radiotherapy (CRT) have a prognostic value in patients with anal carcinoma. Materials and methods: 45 patients with anal cancer who underwent pre-treatment FDG-PET/CT were included. Metabolic parameters, recurrence and anal carcinoma specific survival were analyzed. Results: Shy max and metabolic volume of the primary tumour were significantly higher in patients with lymph node or distant metastases than in those with locally confined disease (p = 0.020 and p = 0.015, respectively). The extent of disease (local tumour only, lymph node or distant metastases) was highly predictive of both for recurrence free and disease specific survival (p = 0.010 and p < 0.001, respectively). Recurrence free (p = 0.010) and anal carcinoma specific survival (p = 0.006) differed significantly between patients with a metabolic volume <45 ml and >45 ml. Multivariate analysis revealed that a metabolic volume >45 ml was the only significant independent determinant (p = 0.19) for recurrence free survival whereas for anal carcinoma specific survival the extent of disease was identified as the only significant independent determinant (p = 0.002). Conclusions: the extent of disease on FDG PET/CT before combined radio-chemotherapy is strongly predictive of prognosis in anal cancer. Furthermore, patients with a large metabolic volume of the primary tumour (>45 ml) are at significantly higher risk of recurrence. (C) 2016 Elsevier Ireland Ltd. All rights reserved.