Hendrik Thoen

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.