Using positron-emission tomography–computed tomography for predicting radiotherapy-induced tumor regression in carcinoma esophagus in an Indian population

• Published in: World journal of nuclear medicine Vol. 18; no. 4; pp. 361 - 365
• Main Authors: Singh, Sankalp, Bisht, Niharika, Sarin, Arti, Kumar, A. V. S., Gupta, Samir, Kapoor, Amul, Mishra, Prabha
• Format: Journal Article
• Language: English
• Published: A-12, 2nd Floor, Sector 2, Noida-201301 UP, India Thieme Medical and Scientific Publishers Pvt. Ltd 01.10.2019; Wolters Kluwer India Pvt. Ltd; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Wolters Kluwer - Medknow
• Subjects: Cancer; Cancer therapies; Carboplatin; Carcinoma; CAT scans; Chemotherapy; Computed tomography; Diagnostic imaging; Emission analysis; Esophageal cancer; Esophagus; Histology; Histopathology; Medical imaging; Medical prognosis; Metabolism; Original; Original Article; Patients; Positron emission; Positron emission tomography; Radiation therapy; Radiotherapy; Studies; Surgery; Tomography; Tumors; India; positron-emission tomography–computed tomography; radiotherapy; Carcinoma esophagus; positron-emission tomography-computed tomography
• ISSN: 1450-1147; 1607-3312
• DOI: 10.4103/wjnm.WJNM_114_18

Abstract Carcinoma esophagus is a common malignancy of the Indian subcontinent. The role of positron-emission tomography–computed tomography (PET-CT) in the assessment of response to radiotherapy has been widely studied and accepted. However, its precise use as a predictive tool for actual histopathological response to radiotherapy needs further evaluation, especially in an Indian population. The aim of this study was to identify a quantum of metabolic response on PET-CT that can also predict for a good pathological response. Forty-four patients of carcinoma esophagus treated with neoadjuvant chemoradiotherapy followed by surgery were included in the study. All patients underwent a PET-CT before starting treatment as well as at 4–6 weeks after completion of radiotherapy. The percentage change in pre and posttreatment maximum standardized uptake value (SUV max ) value (ΔSUV%) of the primary tumor was correlated against histopathological tumor regression grade (TRG) as per the Mandard's system. Seventy-five percent of the patients with a significant metabolic response, i.e., a ΔSUV% of 60% or more, also had a good pathological response to treatment. Thus, by considering a ΔSUV% of 60%, we could predict for a good pathological response (TRG of 1 or 2) to chemoradiotherapy in our patient set with a sensitivity of 95.45% and a specificity of 72.72%.