Shorter, Higher Dose Radiation Regimen is Effective for Advanced Prostate Cancer

Radiation therapy administered in shorter spans at higher doses is an effective and safe option for high-risk prostate cancer, according to a new study from researchers at the University of California, Los Angeles (UCLA).

The team from the UCLA Jonsson Comprehensive Cancer Center sough to verify whether shortening the standard 45-day radiation regimen to a five-day course at increased dosage is a viable treatment option for men with aggressive prostate cancer. Previous studies have confirmed that this method is reliable for low- and intermediate-risk disease.

Data were pooled on 344 patients with high-risk prostate cancer who underwent stereotactic body radiotherapy (SBRT), a form of external beam radiation therapy that administers radiation at a higher dose over four to five days. Patients were followed up for at least 24 months, for a median follow-up of 49.5 months. The researchers used a Kaplan-Meier framework to estimate biochemical recurrence-free survival (BCRFS) and distant metastasis-free survival (DMFS). Genitourinary (GU) and gastrointestinal toxicity was also measured.

Estimated BCRFS and DMFS at four years post-radiation were 81.7% (95% confidence interval [CI], 77.2-86.5) and 89.1% (95% CI, 85.3-93.1), respectively. Incidences of grade 3 or higher GU and GI toxicity were low, at 2.3% and 0.9%, respectively. Severe adverse events were rare, according to the researchers.

In conclusion, the researchers wrote, “These data support a favorable toxicity and efficacy profile for SBRT for high-risk pancreatic cancer (HRPCa). Further prospective studies are needed to evaluate the optimal dose and target volume in the context of SBRT for HRPCa.”

This study was published in the International Journal of Radiation Oncology, Biology, Physics.