Proton beam therapy for bone sarcomas of the skull base and spine: A retrospective nationwide multicenter study in Japan.
We conducted a retrospective, nationwide multicenter study to evaluate the clinical outcomes of proton beam therapy for bone sarcomas of the skull base and spine in Japan. Eligibility criteria included: (i) histologically proven bone sarcomas of the skull base or spine; (ii) no metastases; (iii) ≥20 years of age; and (iv) no prior treatment with radiotherapy. Of the 103 patients treated between January 2004 and January 2012, we retrospectively analyzed data from 96 patients who were followed-up for >6 months or had died within 6 months. Seventy-two patients (75.0%) had chordoma, 20 patients (20.8%) had chondrosarcoma, and four patients (7.2%) had osteosarcoma. The most frequent tumor locations included the skull base in 68 patients (70.8%) and the sacral spine in 13 patients (13.5%). Patients received a median total dose of 70.0 Gy (relative biological effectiveness). The median follow-up was 52.6 (range, 6.3-131.9) months. The 5-year overall survival, progression-free survival, and local control rates were 75.3%, 49.6%, and 71.1%, respectively. Performance status was a significant factor for overall survival and progression-free survival, whilst sex was a significant factor for local control. Acute Grade 3 and late toxicities of ≥Grade 3 were observed in nine patients (9.4%) each (late Grade 4 toxicities [n = 3 patients; 3.1%]). No treatment-related deaths occurred. Proton beam therapy is safe and effective for the treatment of bone sarcomas of the skull base and spine in Japan. However, larger prospective studies with a longer follow-up are warranted.
Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
Yusuke
http://orcid.org/0000-0002-4465-4300
Y
Demizu
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Japan.
Masashi
http://orcid.org/0000-0001-7837-1301
M
Mizumoto
Proton Therapy Division, Radiation and Proton Therapy Center, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka, Japan.
Tsuyoshi
T
Onoe
Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Naoki
N
Nakamura
Department of Radiation Oncology, Southern Tohoku General Hospital, Koriyama, Fukushima, Japan.
Yasuhiro
Y
Kikuchi
Proton Therapy Center, Fukui Prefectural Hospital, Fukui, Japan.
Tetsushi
T
Shibata
Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
Tomoaki
T
Okimoto
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Japan.
Hideyuki
H
Sakurai
Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Tetsuo
T
Akimoto
Clinical Research and Medical Innovation Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
Kota
K
Ono
Department of Biostatistics, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
Takashi
T
Daimon
Proton Therapy Division, Radiation and Proton Therapy Center, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka, Japan.
Shigeyuki
S
Murayama
D001859:Bone Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D061766:Proton Therapy / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012509:Sarcoma / Q000473:pathology / Q000532:radiotherapy*; D019291:Skull Base / Q000473:pathology / Q000528:radiation effects*; D013131:Spine / Q000473:pathology / Q000528:radiation effects*
Multicenter study; proton beam therapy; sarcoma; skull base; spine