Multicenter Study of Carbon-Ion Radiation Therapy for Mucosal Melanoma of the Head and Neck: Subanalysis of the Japan Carbon-Ion Radiation Oncology Study Group (J-CROS) Study (1402 HN).
To evaluate the efficacy and safety of carbon-ion radiation therapy (RT) for mucosal melanoma of the head and neck (MMHN) in the Japan Carbon-Ion Radiation Oncology Study Group study.



Patients with MMHN with N0-1M0 status who were treated with carbon-ion RT at 4 institutions in Japan between November 2003 and December 2014 were analyzed retrospectively. Two hundred sixty patients (male, 111; female, 149; median age, 68 years) with histologically proven MMHN were enrolled.



Primary sites included the nasal cavity in 178 patients, paranasal sinuses in 43, oral cavity in 27, and pharynx in 12. Eighty-six patients had T3 tumors, 147 had T4a tumors, and 27 had T4b tumors. Two hundred fifty-one patients were diagnosed with N0 disease, and 9 with N1 disease. The median total dose and number of fractions were 57.6 Gy RBE (relative biological effectiveness) and 16, respectively. Chemotherapy including dimethyl traizeno imidazole carboxamide was used concurrently in 129 patients. The median follow-up duration was 22 months (range, 1-132 months). The 2-year overall survival and local control rates were 69.4% and 83.9%, respectively. Multivariate analysis showed that gross tumor volume and concurrent chemotherapy were significant prognostic factors for overall survival. Grade 3 and grade 4 late morbidities were observed in 27 and 7 patients (5 developed ipsilateral blindness, 1 mucosal ulcer, and 1 second malignant disease in the irradiated volume), respectively. No patients developed grade 5 late morbidities.



Carbon-ion RT is a promising treatment option for MMHN.
Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan. Electronic address: koto.masashi@qst.go.jp.
Masashi
M
Koto
Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
Yusuke
Y
Demizu
Gunma University Heavy Ion Medical Center, Maebashi, Japan.
Jun-Ichi
JI
Saitoh
Ion Beam Therapy Center, SAGA-HIMAT Foundation, Tosu, Japan.
Hiroaki
H
Suefuji
Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan.
Hiroshi
H
Tsuji
Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
Tomoaki
T
Okimoto
Gunma University Heavy Ion Medical Center, Maebashi, Japan.
Tatsuya
T
Ohno
Ion Beam Therapy Center, SAGA-HIMAT Foundation, Tosu, Japan.
Yoshiyuki
Y
Shioyama
Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan.
Ryo
R
Takagi
Department of Radiation Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
Kenji
K
Nemoto
Gunma University Heavy Ion Medical Center, Maebashi, Japan.
Takashi
T
Nakano
Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan.
Tadashi
T
Kamada
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D063193:Heavy Ion Radiotherapy / Q000401:mortality* / Q000706:statistics & numerical data; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000532:radiotherapy*; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D009367:Neoplasm Staging; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome