Concurrent chemoradiation plays an integral role in the treatment of esophageal cancer. Proton beam radiation therapy has the potential to spare adjacent critical organs, improving toxicity profiles and potentially improving clinical outcomes.

Methods and Materials

We evaluated the REG001-09 registry for patients undergoing proton radiation therapy for esophageal cancer. Demographic, clinicopathologic, toxicity, and dosimetry information were compiled.


We identified 155 patients treated at 10 institutions between 2010 and 2019. One hundred twenty (77%) had adenocarcinoma and 34 (22%) had squamous cell carcinoma. One hundred thirty-seven (88%) received concurrent chemotherapy. The median delivered dose was 50.51 Gy-equivalent (GyE; range, 41.4-70.1). Grade ≥3 toxicities occurred in 22 (14%) of patients and were most commonly dysphagia (6%), esophagitis (4%), anorexia (4%), and nausea (2%). There were no episodes of grade ≥4 lymphopenia and no grade 5 toxicities. The average mean heart, lung, and liver doses and average maximum spinal cord dose were 10.0 GyE, 4.8 GyE, 3.8 GyE, and 34.2 GyE, respectively. For gastroesophageal junction tumors, 8% of patients developed acute grade ≥3 toxicity and the mean heart, liver, right kidney, and left kidney doses were 10.5 GyE, 3.9 GyE, 0.4 GyE, and 4.9 GyE, respectively. Gastroesophageal junction location was protective against development of grade ≥3 toxicity on univariate (P = .0009) and multivariate (P = .004) analysis.


Proton beam radiation therapy affords excellent dosimetric parameters and low toxicity in patients with esophageal cancer treated with curative intent. Prospective trials are underway investigating the comparative benefit of proton-based therapy.

Publication Date


Content Type


Publisher's Site:

View at Publisher Website

Additional Authors:

Additional authors and institutional affiliations


2452-1094/©2021 The Author(s). Published by Elsevier Inc. on behalf of American Society for Radiation Oncology. This is an open access articleunder the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Advances in Radiation Oncology (2021)6, 100751

Open Access

Available to all.