title: Role of18F-FDG PET/CT in Posttreatment Evaluation of Anal Carcinoma.
abstract: The aim of this study was to evaluate the relevance of PET/CT and18F-FDG as a strategy for response evaluation after chemoradiotherapy for anal cancer. For this, the performance of posttreatment18F-FDG PET/CT, the impact on patient care, and the predictive value of metabolic response were assessed.Methods:This was a retrospective and multicenter analysis of 87 patients treated by chemoradiotherapy for anal squamous cell carcinoma between October 2007 and October 2013. All patients underwent systematic posttreatment18F-FDG PET/CT and were followed with at least a clinical examination every 4 mo for 2 y and every 6 mo thereafter. Disease progression was confirmed by biopsy for all patients in the case of local recurrence before surgery. Kaplan-Meier and Cox regression models were used to test for associations between metabolic or clinical endpoints and progression-free survival (PFS) or cause-specific survival (CSS).Results:The median follow-up was 25 mo.18F-FDG PET/CT was performed 1-8 mo (median, 4 mo) after completion of chemoradiotherapy. Overall, 25 patients relapsed and 13 died. The posttherapy18F-FDG PET/CT did not show any abnormal18F-FDG uptake (complete metabolic response [CMR]) in 55 patients whereas 32 displayed incomplete response (non-CMR): 15 patients with partial response and 17 with disease progression. The sensitivity of18F-FDG PET/CT to detect residual tumor tissue was 92% (95% confidence interval [CI], 75%-97%), specificity was 85% (95% CI, 75%-92%), positive predictive value was 72% (95% CI, 61%-90%), and negative predictive value was 96.4% (95% CI, 90%-98.7%). The 2-y PFS was 96% (95% CI, 90-100) for patients with CMR and 28% (95% CI, 14-47) for non-CMR patients (P< 0.0001). The 2-y CSS was 100% for patients with CMR and 59% (95% CI, 42-84) for those without CMR (P< 0.0001).18F-FDG PET/CT changed patient management in 14 cases (16%), with relevant modifications in 12 (14%). A Cox proportional hazards model of survival outcome indicated that a CMR was the only significant predictor of PFS and CSS (P< 0.0001).Conclusion:18F-FDG PET/CT shows good accuracy in posttreatment evaluation of anal cancer and has a relevant impact on patient management. Moreover, CMR is associated with good survival outcome. Thus,18F-FDG PET/CT may play a significant role during posttreatment follow-up of anal cancer.
authors.affiliation: Nuclear Medicine Department, CHU de Bordeaux, F-33000 Bordeaux, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Houard
authors.affiliation: Nuclear Medicine Department, CHU de Bordeaux, F-33000 Bordeaux, France jean-baptiste.pinaquy@chu-bordeaux.fr.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Pinaquy
authors.affiliation: Nuclear Medicine Department, CHU de Bordeaux, F-33000 Bordeaux, France.|Université de Bordeaux, F-33000 Bordeaux, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Mesguich
authors.affiliation: Radiotherapy Department, Bergonié Institute, F-33000 Bordeaux, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Henriques de Figueiredo
authors.affiliation: Nuclear Medicine Department, Bergonié Institute, F-33000 Bordeaux, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Cazeau
authors.affiliation: Nuclear Medicine Department, Bayonne General Hospital, Bayonne, France.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Allard
authors.affiliation: Radiotherapy Department, Private Hospital Tivoli, F-33000 Bordeaux, France.
authors.forename: Hortense
authors.initials: H
authors.lastname: Laharie
authors.affiliation: Nuclear Medicine Department, CHU de Bordeaux, F-33000 Bordeaux, France.|Université de Bordeaux, F-33000 Bordeaux, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Bordenave
authors.affiliation: Nuclear Medicine Department, CHU de Bordeaux, F-33000 Bordeaux, France.|Université de Bordeaux, F-33000 Bordeaux, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Fernandez
authors.affiliation: Radiotherapy Department, CHU de Bordeaux, F-33000 Bordeaux, France; and.|INSERM U1035, F-33000 Bordeaux, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Vendrely
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001005:Anus Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: anus neoplasms; chemoradiotherapy; fluorodeoxyglucose F18; positron-emission tomography