TY - JOUR T1 - Surveillance of Clinically Complete Responders Using Serial <sup>18</sup>F-FDG PET/CT Scans in Patients with Esophageal Cancer After Neoadjuvant Chemoradiotherapy JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 486 LP - 492 DO - 10.2967/jnumed.120.247981 VL - 62 IS - 4 AU - Maria J. Valkema AU - Berend J. van der Wilk AU - Ben M. Eyck AU - Bas P.L. Wijnhoven AU - Manon C.W. Spaander AU - Michail Doukas AU - Sjoerd M. Lagarde AU - Wendy M.J. Schreurs AU - Mark J. Roef AU - J. Jan B. van Lanschot AU - Roelf Valkema Y1 - 2021/04/01 UR - http://jnm.snmjournals.org/content/62/4/486.abstract N2 - Active surveillance for patients with esophageal cancer and a clinically complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT) is being studied. Active surveillance requires accurate clinical response evaluations. 18F-FDG PET/CT might be able to detect local tumor recurrence after nCRT as soon as the esophagus recovers from radiation-induced esophagitis. The aims of this study were to assess the value of serial 18F-FDG PET/CT scans for detecting local recurrence in patients beyond 3 mo after nCRT and to determine when radiation-induced esophagitis has resolved. Methods: This retrospective multicenter study included patients who had cCR after nCRT, who initially declined surgery, and who subsequently underwent active surveillance. Clinical response evaluations included 18F-FDG PET/CT, endoscopic biopsies, and endoscopic ultrasound with fine-needle aspiration at regular intervals. SUVmax normalized for lean body mass (SULmax) was measured at the primary tumor site. The percentage change in SULmax (Δ%SULmax) between the last follow-up scan and the scan at 3 mo after nCRT was calculated. Tumor recurrence was defined as biopsy-proven vital tumor at the initial tumor site. Results: Of 41 eligible patients, 24 patients had recurrent disease at a median of 6.5 mo after nCRT and 17 patients remained cancer free during a median follow-up of 24 mo after nCRT. Five of 24 patients with tumor recurrence had sudden intense SULmax increases of greater than 180%. In 19 of 24 patients with tumor recurrence, SULmax gradually increased (median Δ%SULmax, +18%), whereas SULmax decreased (median Δ%SULmax, −12%) in patients with ongoing cCR (P &lt; 0.001, independent-samples t test). In patients with ongoing cCR, SULmax was lowest at 11 mo after nCRT. Conclusion: Serial 18F-FDG PET/CT might be a useful tool for detecting tumor recurrence during active surveillance. In patients with ongoing cCR, the lowest SULmax was reached at 11 mo after nCRT, suggesting that radiation-induced esophagitis had mostly resolved by that time. These findings warrant further evaluation in a larger cohort. ER -