The annual meeting of the American Society for Radiation Oncology was held from Sept. 15 to 18 in Chicago and attracted approximately 11,000 participants from around the world, including physicians, oncology nurses, radiation therapists, biologists, physicists, and other cancer researchers. The conference featured educational courses focusing on radiation, surgical, and medical oncology.
In a phase II study, Allison M. Campbell, M.D., Ph.D., of the Yale Cancer Center in New Haven, Connecticut, and colleagues found that among a percentage of patients with metastatic non-small cell lung cancer who failed to respond to immunotherapy alone, adding stereotactic body radiotherapy (SBRT) to immunotherapy (pembrolizumab) improved progression-free survival.
“Ten percent of patients who had already progressed on immunotherapy had a partial response to radiation that lasted for longer than one year. Tumors that weren’t targeted with radiation shrank, and this was associated with more CD8 effector memory T cells in the peripheral blood,” Campbell said. “It’s too early to make definitive statements about the benefit of adding SBRT for patients who have progressed on immunotherapy, but the approach is already being used in the clinic. When patients progress on immunotherapy (off trial), growing tumors are associated with pain, and radiation is a natural choice for palliation at those sites. It’s becoming more common to treat those sites with SBRT, especially in patients who don’t have a lot of metastatic sites (patients with oligometastatic disease).”
In another study, Clifford Robinson, M.D., of the Washington University School of Medicine in St. Louis, and colleagues found that a single dose of radiation therapy was able to reduce ventricular tachycardia (VT) for patients with VT refractory to medication and catheter ablation, allowing for reduced medication and improved quality of life.
“For up to 78 percent of patients alive at two years, the effect was durable. Late complications were few, but did occur, including pericardial effusion and a gastropericardial fistula; thus, further long-term follow-up is warranted,” Robinson said. “For patients with refractory VT, few options exist. A completely noninvasive approach using noninvasive imaging and radiation therapy may provide new hope for these patients.”
Daniel Spratt, M.D., of the University of Michigan Rogel Cancer Center in Ann Arbor, and colleagues found that men with recurring prostate cancer and prostate-specific antigen (PSA) values less than 0.6 ng/mL who underwent early salvage radiotherapy (SRT) showed no improvement in metastasis or survival from the addition of long-term hormone therapy. Furthermore, the investigators found that high-dose bicalutamide resulted in a twofold increased risk in other-cause mortality and threefold to 4.5-fold higher odds of having a severe cardiac event.