The preliminary result of proton and carbon ion therapy for recurrent chordoma and chondrosarcoma of skull base and cervical spine / 中华放射医学与防护杂志

ABSTRACT

Objective:To evaluate the short-term tumor control and toxicity of recurrent skull base and cervical spine chordoma and chondrosarcoma in patients treated with pencil beam scanning proton and heavy ion therapy.Methods:Between June 30 th, 2014 and July 30 th, 2018, a total of 45 skull base and cervical spine chordoma ( n=39) and chondrosarcoma ( n=6) patients (28 males and 17 females; mean age at initial presentation of 44 years, range, 14-76 years) were treated in our center for the course of radiotherapy. The median maximum tumor volume was 57 cm 3 (range, 6.6-231.7 cm 3). There were 31 post-operative recurrent patients and 14 post-operative and post-radiated recurrent patients. One patient received proton therapy, 21 patients received combined proton and carbon ion therapy, 23 patients received carbon ion therapy. Results:All patients completed the whole course of the treatment. The median follow-up time was 29 months (range 8-57 months), the 2-year overall survival (OS), local control (LC), and progression-free survival (PFS) were 82.7%, 85.3%, and 73.8%, respectively. There were no other grade 3-4 acute or late radiation-induced toxicity except one grade 3 acute mucositis. The 2-year OS rates for patients after first-time radiation vs. re-irradiation were 96.2% and 50.3% ( χ2=16.969, P<0.05). Conclusions:The short-term outcomes of pencil beam scanning proton and heavy ion therapy for recurrent skull base and cervical spine chordoma and chondrosarcoma is favorable. Further study is needed for long-term efficacy and safety.