A specific radiation therapy called carbon ion radiotherapy (CIRT) can control cancer growth and prolong survival in patients with inoperable spinal tumors, according to a study published online Monday in the US journal CANCER.

Researchers from the National Institute of Radiological Sciences in Japan hailed the treatment as "a promising alternative " for patients whose spinal tumors are unable to be surgically removed.

In the study, Reiko Imai from the National Institute of Radiological Sciences and her colleagues analyzed the outcomes of 47 patients with medically unresectable spinal sarcomas, excluding sacral tumors, who received treatment with CIRT between 1996 and 2011.

The analysis found tumor growth was controlled for at least five years in 79 percent of patients. It also revealed that 52 percent of patients survived for at least five years with 48 percent of patients surviving that long without experiencing cancer progression.

The researchers reported that patients experienced "no fatal toxicities" from the treatment. However, one patient had a skin reaction, seven patients experienced vertebral compression salvaged by surgical intervention, and one developed a spinal cord reaction.

At the last follow-up appointment, 22 of the 28 patients who were alive could walk without supportive devices.

The researchers said the CIRT treatment "appears to be both effective and safe" for those suffering from unresectable spinal sarcoma

"This report is the first one regarding spinal sarcomas treated with carbon ion radiotherapy," said Imai in a statement. "And our findings offer a treatment alternative to patients with inoperable tumors."