A study published in JAMA suggested that a single dose of radiotherapy is as effective as 5 doses for patients with malignant metastatic solid tumors and spinal canal compression.1
“At the moment, with no recommended radiotherapy schedule for these patients, many are given several doses of radiation treatment, and each dose requires a separate visit to the hospital. Patients and their [caregivers] have to make multiple journeys, which can be uncomfortable to patients, inconvenient and expensive,” Allan Hackshaw, professor at the University College London Cancer Institute, said in a press release.2
In this multicenter cohort of 686 patients with spinal cord or cauda equina compression, overall survival rates at 12 weeks were 50% in the single-fraction group vs 55% in the multi-fraction group (stratified hazard ratio, 1.02; 95% CI, 0.74-1.41). Of the 11 other secondary endpoints, the differences between each group were not statistically significant or did not meet noninferiority criteria.
Ambulatory status grade 1 or 2 at week 8 was achieved by 115 of 166 patients in the single-fraction group vs 128 of 176 in the multi-fraction group (difference, -3.5% [1-sided 95% CI, -11.5% to ∞]; P value for noninferiority = .06). At week 12, 71.8% of single-fraction patients achieved ambulatory status vs 67.7% of multi-fraction patients.
Only 49.8% of participants were analyzed for the primary endpoint, as 255 patients died before the 8-week assessment. Of all the patients, 44% had prostate cancer, 19% had lung cancer, and 12% had breast cancer; 73% were men.
“We believe our findings, which show equal clinical effectiveness for single-dose radiotherapy, provide strong evidence for NICE guidelines, and those in other countries, to be changed to stipulate a 1-dose 1-visit approach, reducing unnecessary discomfort for end of life cancer patients without compromising efficacy,” Hacksaw said.
The trial evaluated 15 prespecified secondary end points; ambulatory status at 1, 4, and 12 weeks, loss of ambulation, ambulatory recovery, additional treatment, supportive care, quality of life (global, physical, emotional, and pain dimensions), grade 3 or 4 adverse events, bladder and bowel functioning, and overall survival. These outcomes were not significantly different between treatment groups.
Fewer patients given the single dose experienced adverse skin reactions (12% vs 19%), and fewer patients also encountered fatigue (49% vs 55%). However, a group of patients who had radiation treatment specifically to the lower spinal cord (cauda equina) were more likely to have bladder problems, and one radiotherapy dose may not have been enough for these patients in particular.
Only 2 other randomized studies have compared single dose radiotherapy with multi-dose, specifically in regard to managing spinal canal compression, and both were small trials.
Spinal canal compression is common in patients with metastatic cancer and affected an estimated 4,000 patients in the U.K. in 2008 and 25,000 in the U.S. in 2005. Most patients are treated with radiotherapy in 5 to 10 fractions of 20 to 30 Gy.
1. Hoskin PJ, Hopkins K, Misra V, et al. Effect of Single-Fraction vs Multifraction Radiotherapy on Ambulatory Status Among Patients With Spinal Canal Compression From Metastatic Cancer. JAMA. doi:10.1001/jama.2019.17913.
2. One dose of radiotherapy as effective as five doses for cancer in the spine [news release]. London, England. Published December 3, 2019. ucl.ac.uk/news/2019/dec/one-dose-radiotherapy-effective-five-doses-cancer-spine. Accessed December 6, 2019.