Carbon ion radiotherapy (CIRT) appears to be safe and effective for the treatment of persons with unresectable spinal sarcoma, researchers have affirmed.
Although surgery is the mainstay of treatment for spinal sarcoma, these tumors have been one of the most challenging diseases for orthopedic surgeons, according to Reiko Imai, MD, PhD, of the Research Center Hospital for Charged Particle Therapy at the National Institute of Radiological Sciences in Chiba, Japan, and colleagues. In addition, some patients are ineligible for surgery due to their condition or the location of the tumor.
In such cases, radiation therapy generally is used, and CIRT is a form of radiation therapy known to be effective for the treatment of various types of inoperable sarcomas.
To study the effectiveness and safety of CIRT in inoperable spinal sarcomas specifically, Imai and her team retrospectively analyzed outcomes from 47 patients (median age 54 years) with 48 unresectable spinal sarcomas, excluding sacral tumors. The patients had all undergone CIRT between 1996 and 2011 as participants in phase 1/2 and phase 2 clinical trials of CIRT for bone and soft tissue sarcoma. The applied dose ranged from 52.8 gray equivalents (GyE) to 70.4 GyE (median 64 GyE) in 16 fixed fractions over 4 weeks. Median follow-up was 25 months.
As Imai’s group reported in the journal Cancer, median survival was 44 months (range 5.2–148 months), and 5-year local control, overall survival, and progression-free survival rates were 79%, 52%, and 48%, respectively. None of the 15 patients with tumors smaller than 100 cm3 had local recurrence.
In terms of adverse effects, no fatal toxicities occurred during follow-up, but one patient had a grade 3 late skin reaction and another had a grade 4 late skin reaction. Vertebral body compression was observed in seven patients, and one patient had a grade 3 late spinal cord reaction. Of the 28 patients with primary tumors surviving at last follow-up appointment, 22 (78.5%) were able to walk without supportive devices.
“This report is the first one regarding spinal sarcomas treated with carbon ion radiotherapy, and our findings offer a treatment alternative to patients with inoperable tumors,” commented Imai in a statement accompanying the release of the study.