Photons Versus Protons for Spinal Cord Gliomas Treatment

Introduction

A study comparing the long-term outcomes of patients with spinal-cord tumors following radiation therapy suggests that certain subsets of patients have better long-term survival. It also suggests that photon-based radiation therapy may result in better survival than proton-beam therapy, even in patients with more favorable characteristics.

Main Item

Proton Therapy / Proton Beam Therapy

Proton therapy or proton beam therapy is defined as a medical procedure, a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often in the treatment of cancer. Proton therapy's main advantage over other types of external beam radiotherapy is that as a charged particle the dose is deposited over a narrow range and there is minimal exit dose. Because proton beams can be delivered in higher doses and with far more accuracy, proton therapy typically can control cancer with fewer treatments than intensity-modulated radiation therapy (IMRT). Fewer treatment complications mean that physicians can deliver higher doses of proton radiation to cancer sites, and an increased dose of proton radiation can improve the chances for a successful outcome.

This is the first study to report the long-term outcomes of spinal-cord tumor patients treated by modern radiotherapy techniques, the researchers say. Gliomas, which represent most spinal cord tumors, develop in about 17,000 Americans annually, and 13,000 die from them.

"Our findings need to be verified in a larger number of patients, but they suggest that individuals younger than age 54, those with ependymomas and those treated with photon-based therapy versus proton-beam treatment have better overall survival," says principal investigator Dr. Arnab Chakravarti, chair and professor of Radiation Oncology and co-director of the Brain Tumor Program at The Ohio State Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute.

"Perhaps most surprising is that the subset of spinal-cord tumor patients treated by protons appears to do worse, even though they have more favorable pre-treatment demographics," Chakravarti says. "This certainly warrants validation in a larger subset of patients."

Surgery is the standard therapy for spinal-cord tumors, and it is often followed by radiotherapy. But whether all patients or only certain patients should receive radiation therapy is controversial, Chakravarti says.

The research is published in a recent issue of the International Journal of Radiation Oncology, Biology, Physics.

The retrospective study examined the long-term outcomes of 32 patients with primary spinal-cord gliomas. Twenty-two of the patients were treated with photon-beam radiation therapy (such as 3-D conformal radiation and intensity-modulated radiotherapy), and 10 were treated with proton-beam therapy.

The five-year overall survival rate was 65 percent and the progression free survival was 61 percent for the group. The study also showed poorer overall survival for the following patients:

• Those age 55 and older.
• Those with astrocytomas versus ependymomas.
• Those who had a biopsy versus those whose tumor was surgically removed.

Chakravarti is the Max Morehouse Chair in Cancer Research.

Ohio State researcher Dr. E. Antonio Chiocca also contributed to this study.

Funding from the National Cancer Institute and the Brain Tumor Funders Collaborative Group supported this research.

The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (cancer.osu.edu) is one of only 40 Comprehensive Cancer Centers in the United States designated by the National Cancer Institute. Ranked by U.S. News & World Report among the top cancer hospitals in the nation, The James is the 180-bed adult patient-care component of the cancer program at The Ohio State University. The OSUCCC-James is one of only seven funded programs in the country approved by the NCI to conduct both Phase I and Phase II clinical trials.

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Attribution/Source(s): This quality-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by Ohio State University Medical Center and published on 2010/12/22, this content may have been edited for style, clarity, or brevity. For further details or clarifications, Ohio State University Medical Center can be contacted at wexnermedical.osu.edu NOTE: Disabled World does not provide any warranties or endorsements related to this article.