Stereotactic ablative radiation therapy can achieve more than 90% control of renal cell carcinoma metastases, according to a study published in the International Journal of Radiation Oncology, Biology, and Physics (May 1, 2017;98:91-100).
Approximately 400,000 Americans are currently living with a kidney cancer diagnosis. The standard of care for metastatic renal cell carcinoma is systemic therapy using targeted drugs and immunotherapy because this disease state is refractory to conventional radiation therapy. However, these therapies are often associated with significant adverse events. Researchers are investigating new methods of treatment for metastatic renal cell carcinoma.
Raquibul Hannan, MD, PhD, assistant professor of radiation oncology, Kidney Cancer Program, and colleagues conducted a study to assess the efficacy of stereotactic ablative radiation therapy in treating patients with extracranial renal cell carcinoma metastases. Researchers analyzed 175 metastatic lesions from 84 patients treated with stereotactic ablative radiation therapy from 2005 to 2015. The primary outcome was local control.
Therapy was administered in 5 fractions (40-60 Gy), 3 fractions (30-54 Gy), and a single fraction (20-40 Gy) in most cases.
Researchers found that after 12 months, the local control rate was 91.2% (95% CI, 84.9%-95.0%; median follow-up, 16.7 months) of these lesions. Acute and late grade 3 toxicities after therapy were reported in only 3 patients (1.7%) and 5 patients (2.9%), respectively.
"This study shows that stereotactic radiation provides a good noninvasive alternative to conventional treatment, and that it effectively controls the disease," said Dr Hannan in a press release (May 2, 2017). "It may also offer an alternative to patients who are not candidates for surgery due to the number and location of the metastases."
Results of the study also indicate that multimodality treatment with surgery should be considered for re-irradiation or vertebral metastasis and that a higher radiation dose may be necessary for patients who received prior systemic therapies. — Zachary Bessette