Background/aim: To determine the most reliable predictor for pathologic complete response (pCR) in patients who underwent preoperative chemoradiotherapy and regional hyperthermia (HCRT) for rectal cancer.
Patients and methods: Thirty-six patients were enrolled. The local control status of the patients was assessed using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), magnetic resonance imaging (MRI), and colonoscopy before and after HCRT. The relationships between various parameters of these clinical examinations and pCR were analyzed.
Results: Ten (28%) patients achieved pCR. The accuracies of predicting pCR using FDG-PET/CT, MRI, and colonoscopy were 78%, 61%, and 75%, respectively. FDG-PET/CT was the only independent predictive modality for pCR (p=0.021). The maximum standardized uptake value (SUVmax) and SUVmax normalized to liver uptake (SLR) after HCRT showed the highest sensitivity (90%) and the decreasing rate of SUVmax and SLR demonstrated the highest specificity (89%) for pCR.
Conclusion: SUVmax-based parameters of FDG-PET/CT after HCRT were the most reliable predictors for pCR.
Keywords: FDG-PET/CT; Rectal cancer; chemoradiotherapy; hyperthermia; pathologic complete response.
Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.