Refractory Sarcomas Respond to Carbon Ion Particle Beams

Laurie Barclay, MD

November 25, 2002

Nov. 25, 2002 — Carbon ion particle beams have demonstrated the highest response to date for refractory bone and soft tissue sarcomas, according to a report in the Nov. 15 issue of the Journal of Clinical Oncology. This technique may offer a viable alternative to surgical resection.

"Management strategies for bone and soft tissue sarcomas (BSTSs) have changed dramatically in the last three decades. Aggressive chemotherapy and/or radiation in combination with limb preservation surgery is now the treatment of choice for most patients," write Tadashi Kamada, MD, from the National Institute of Radiological Sciences in Chiba, Japan, and colleagues. "In cases when BSTSs are unresectable, radioresistant, and/or located near critical organs, various particle beams offer promising results."

In this phase I/II dose escalation study of carbon ion radiotherapy, 57 patients with 64 sites of unresectable BSTS received carbon ion radiotherapy. Tumors involved the spine or paraspinous soft tissues in 19 patients, the pelvis in 32 patients, and the extremities in six patients. The median tumor size was 559 cm 3 (range, 20-2,290 cm 3). Carbon ion radiotherapy total dose ranged from 52.8 to 73.6 gray equivalent (GyE), administered in 16 fixed fractions, 3.3 to 4.6 GyE/fraction, over four weeks.

Of 17 patients treated with the highest total dose of 73.6 GyE, seven experienced acute skin reactions of grade 3 by Radiation Therapy Oncology Group criteria. Dose escalation was therefore stopped at this level. There were no other severe acute reactions higher than grade 3 in this series.

Minimum follow-up was 18 months, with overall local control rates of 88% at one year and 73% at three years of follow-up. Median survival time was 31 months (range, 2-60 months); one-year overall survival was 82%; and three-year overall survival was 46%.

"Carbon ion radiotherapy seems to be a safe and effective modality in the management of bone and soft tissue sarcomas not eligible for surgical resection, providing good local control and offering a survival advantage without unacceptable morbidity," the authors write, noting the need for additional studies. "We found a dose-response relationship for local control.... The local control rates in our high-dose group (64 GyE or higher) could be some of the best achieved without surgical resection. Although the focus of this study was not directed at survival duration, nonetheless it is noteworthy that improved local control resulted in better survival in a selected subgroup."

J Clin Oncol. 2002;20(22):4466-4471

Reviewed by Gary D.Vogin, MD


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: