Fox Chase Study Finds PLDR Improves Patient Safety While Preserving Outcomes

Published Date: September 30, 2025

Researchers at Fox Chase Cancer Center have shown that pulsed low dose rate (PLDR) chemoradiation therapy can significantly reduce treatment side effects while maintaining effectiveness for patients with esophageal cancer and non-small cell lung cancer.

The study, “PLDR Chemoradiation for Esophageal and Lung Cancer Is Associated With Low Rates of Severe Esophagitis,” was presented at ASTRO 2025.

“Historically, we’ve been limited in how much radiation we could safely deliver to these patients because of severe side effects, particularly painful swallowing problems,” said Joshua Meyer, MD, FASTRO, Vice Chair of Translational Research and Professor in the Department of Radiation Oncology at Fox Chase, and lead investigator of the study. “The beauty of this technique is that we’re not compromising on cancer treatment. We’re delivering the same effective dose, just in a smarter way that minimizes damage to healthy tissue.”

Key Findings

Reduced Side Effects: Severe esophagitis — inflammation that causes pain and difficulty swallowing — fell from the typical 40% with standard chemoradiation to 26%.
Strong Survival Outcomes: Patients reached a median overall survival of 45 months.
Comparable Response Rates: Among esophageal cancer patients who later had surgery, 19% had a complete pathologic response and 23% showed near-complete responses.

Unlike conventional radiation, which delivers the dose continuously, PLDR breaks the treatment into short pulses spaced minutes apart. This gives healthy cells time to repair DNA damage, while cancer cells, less capable of repair, remain vulnerable.

The phase I trial included 39 patients with locally advanced disease — 35 with esophageal cancer and four with non-small cell lung cancer. All received standard chemotherapy (carboplatin and paclitaxel) with PLDR radiation over 5.5 to 6 weeks. The approach reduced toxicity without compromising effectiveness.

“We were very pleased to see that not only did we cut severe esophagitis roughly in half, but we also preserved the treatment effectiveness we expect,” Meyer said.

PLDR radiation was pioneered at Fox Chase by Chang-Ming Charlie Ma, PhD, FASTRO, Vice Chair of Radiation Oncology and Director of Radiation Physics. Ma developed much of the methodology to ensure optimal delivery. This trial is the first to test PLDR systematically as an initial treatment approach, expanding on prior success in recurrent cancers.