By Kim Polacek, APR, CPRC - October 05, 2023
New advances in radiation therapy delivery were the focus of the plenary session at this year’s
American Society for Radiation Oncology Annual Meeting in San Diego. Each of the abstracts focused on delivering therapy faster and more efficiently to save patients time and improve quality of life.
Outcomes and Toxicity Favorable with Shortened Radiation Treatment for Prostate Cancer
The PACE B (Prostate Advances in Comparative Evidence) study highlights the benefits of stereotactic body radiation therapy (SBRT) for prostate cancer patients. The phase 3 randomized study found SBRT performed as well as standard treatment with moderately fractionated radiation for patients with localized disease. SBRT was delivered in high doses over five treatment sessions, compared to conventional lower dose radiation therapy delivered over several weeks. The five-year disease control rate was 96% with SBRT and 95% for conventional radiation.
“At Moffitt, we preferentially opt for SBRT for men with few significant urinary symptoms and who have smaller prostate glands (<60cc). We have found this population does very well with SBRT of five fractions over 10 days, especially when MR guidance and gel spacers are used,” said Dr. Peter Johnstone, vice chair & clinical director of the Department of Radiation Oncology at Moffitt Cancer Center.
"At Moffitt, we preferentially opt for SBRT for men with few significant urinary symptoms and who have smaller prostate glands."- Dr. Peter Johnstone, Department of Radiation Oncology
“The outcomes for patients in both study arms were better than we expected,” said Dr. Nicholas van As, principal investigator for the trial and medical director of The Royal Marsden NHS Foundation Trust. “While both options are effective, SBRT should be considered as a new standard of care for this patient population.”
High Dose Radiation Improved Survival in Small Cell Lung Cancer
Limited stage small cell lung cancer has a poor prognosis. Standard radiotherapy for this patient population includes 45 Gy dose twice a day. However, results of a phase 3 randomized trial suggest a higher dose may be a better option for this patient population.
The study compared standard radiotherapy to high dose hyperfractionated radiotherapy (54 Gy twice a day). Results show both improved overall survival of 43.1 months to 62.4 months, respectively, and progression-free survival of 16.7 months to 30.5 months, respectively.
Abstract discussant Dr. Kristin Higgins of Winship Cancer Institute of Emory University said that while the study is important, it did have limitations. “It was a carefully selected patient population and not representative of most limited stage small cell lung cancer patients. As further data emerges, integration of 54 Gy will be important, but we need more details, and it may not be applicable for all patients.”
Radiation therapy remains one of the most common treatments for cancer. About half of all cancer patients will require this type of therapy. Clinical trial findings, like the ones presented at this year’s ASTRO meeting, are crucial to advancing the standard of care for patients.