An early clinical trial of focused radiation therapy for liver metastases appeared to be safe without causing liver disease.
Stereotactic body radiotherapy (SBRT) delivers high doses of radiation to a carefully targeted area of the body. Its goal is to destroy cancer cells while leaving healthy tissue unharmed.
Radiation oncologists at Princesss Margaret Hospital at the University of Toronto used SBRT to treat 68 patients with cancer that had spread to their liver, 40 of whom had colorectal cancer. Patients, who were not eligible for surgery or additional chemotherapy, had six radiotherapy treatments over two weeks.
No patients in the trial develop radiation-induced liver disease. Some patients experienced pain, changes in liver enzymes, nausea, and fatigue, but overall serious side effects were limited.
About half of the patients (49 percent) had tumors shrink (respond) after treatment including 4 complete and 29 partial responses. 56 patients did have their cancer recur — 8 in the tumor treated with SBRT, 22 in other parts of their liver, and 34 in areas of the body outside the liver.
Median survival time for all patients was 17.6 months, and median time before cancer got worse (progressed) was 3.6 months. 63 percent of colorectal cancer patients lived at least a year after treatment.
Mark Lee and his colleagues at the University of Toronto concluded,
Individualized six-fraction liver metastases SBRT is safe, with sustained local control observed in the majority of patients.