Prognostic Impact of Pretherapeutic FDG-PET in Localized Anal Cancer

• Published in: Cancers Vol. 12; no. 6; p. 1512
• Main Authors: Le Thiec, Maelle, Testard, Aude, Ferrer, Ludovic, Guillerminet, Camille, Morel, Olivier, Maucherat, Bruno, Rusu, Daniela, Girault, Sylvie, Lacombe, Marie, Hamidou, Hadji, Meyer, Véronique, Rio, Emmanuel, Hiret, Sandrine, Kraeber-Bodéré, Françoise, Campion, Loïc, Rousseau, Caroline
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 09.06.2020; MDPI
• Subjects: Anus; Cancer; Clinical medicine; Colorectal cancer; Image processing; Life Sciences; Lymph nodes; Lymphatic system; Medical prognosis; Metabolism; Metastasis; Methods; Patients; Positron emission tomography; Segmentation; Squamous cell carcinoma; Tumors; FDG-PET; metabolic tumour volume; anal cancer; prognosis
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers12061512

Due to the heterogeneity of tumour mass segmentation methods and lack of consensus, our study evaluated the prognostic value of pretherapeutic positron emission tomography with fluorodeoxyglucose (FDG-PET) metabolic parameters using different segmentation methods in patients with localized anal squamous cell carcinoma (SCC). Eighty-one patients with FDG-PET before radiochemotherapy were retrospectively analyzed. Semiquantitative data were measured with three fixed thresholds (35%, 41% and 50% of Maximum Standardized Uptake Value (SUVmax)) and four segmentation methods based on iterative approaches (Black, Adaptive, Nestle and Fitting). Metabolic volumes of primary anal tumour (P-MTV) and total tumour load (T-MTV: P-MTV+ lymph node MTV) were calculated. The primary endpoint was event-free survival (EFS). Seven multivariate models were created to compare FDG-PET tumour volumes prognostic impact. For all segmentation thresholds, PET metabolic volume parameters were independent prognostic factor and T-MTV variable was consistently better associated with EFS than P-MTV. Patient’s sex was an independent variable and significantly correlated with EFS. With fixed threshold segmentation methods, 35% of SUVmax threshold seemed better correlated with EFS and the best cut-off for discrimination between a low and high risk of event occurrence was 40 cm3. Determination of T-MTV by FDG-PET using fixed threshold segmentation is useful for predicting EFS for primary anal SCC. If these data are confirmed in larger studies, FDG-PET could contribute to individualized patient therapies.