Tumor recurrence and in-field control after multimodality treatment of locally advanced esophageal cancer.

PURPOSE: Neoadjuvant chemoradiotherapy is used prior to surgery in curative treatment of esophageal cancer (EC). We evaluated the in-field control of this multimodal treatment by extraction of radiation dose parameters and determination of the spatial relation between tumor recurrence location(s) and radiation target volume (RTV). METHODS AND MATERIALS: Treatment consisted of neoadjuvant chemotherapy (5-FU and cisplatin) and radiotherapy (36 Gy) followed by Ivor-Lewis esophagectomy. For patients with locoregional recurrence(s), image fusion was performed between radiotherapy planning CT and follow-up CT(s). A region-of-interest was contoured on the planning CT around each locoregional recurrence. Mean and maximum radiation doses were then extracted to classify recurrences as out-of-field, marginal or in-field. RESULTS: Eighty patients were included. The median follow-up duration was 19 months. Fifteen of 95 locoregional recurrences were detected in the RTV. These in-field relapses occurred in only 6 patients (7.8%) on 12 different anatomical locations. None of the patients with in-field failure had a pCR and all had concurrent distant failure on multiple anatomical sites. CONCLUSION: Neoadjuvant chemoradiotherapy followed by Ivor-Lewis esophagectomy yields excellent in-field control, as only a clear minority (7.8%) of patients developed a relapse in the RTV. In-field recurrence is associated with widespread tumor dissemination and poor pathological response to neoadjuvant treatment.