Clinical results of definitive intensity-modulated radiation therapy for oropharyngeal cancer: retrospective analysis of treatment efficacy and safety.
OBJECTIVE
To evaluate the clinical outcomes of intensity-modulated radiotherapy for patients with oropharyngeal carcinoma.


METHODS
Ninety-three oropharyngeal carcinoma patients histopathologically diagnosed with squamous cell carcinoma and treated with definitive intensity-modulated radiotherapy using helical tomotherapy between January 2006 and December 2013 were analyzed. Planning target volume primary and involved nodes was delivered 66-70 Gy at 2 Gy per fraction, while planning target volume prophylactic was delivered 54 Gy using the simultaneous integrated boost technique.


RESULTS
The median follow-up period among the surviving patients was 40 months (range, 13-96). There were 76 males and 17 females with a median age of 60 years (range, 34-80). The disease was Stage II in 13%, Stage III in 10% and Stage IV in 77% of patients. Ninety-two patients received chemotherapy (99%); 68 patients received induction chemotherapy (73%), while 21 received concurrent chemotherapy (23%). The 3-year overall survival, progression-free survival and locoregional control rates were 80, 68 and 79%, respectively. Multivariate analysis identified an advanced T-category (T3-4), having double cancer, and smoking habit as significantly unfavorable factors for overall survival, progression-free survival and both progression-free survival and locoregional control, respectively. Only two patients who achieved disease control required percutaneous endoscopic gastrostomy tubes in the last follow-up. The rate of Grade 2 xerostomia at 2 years was 23%.


CONCLUSIONS
Intensity-modulated radiotherapy using helical tomotherapy for patients with oropharyngeal carcinoma provided not only sufficient efficacy, but also preserved parotid function.
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya.
Kana
K
Kimura
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya 109103@aichi-cc.jp.
Takeshi
T
Kodaira
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya.
Natsuo
N
Tomita
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya.
Hiroyuki
H
Tachibana
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya.
Chiyoko
C
Makita
Department of Radiation Oncology, Aichi Cancer Center Hospital, Chikusaku, Nagoya.
Maiko
M
Yoshida
Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Chikusaku, Nagoya, Japan.
Daisuke
D
Nishikawa
Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Chikusaku, Nagoya, Japan.
Hitoshi
H
Hirakawa
Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Chikusaku, Nagoya, Japan.
Hidenori
H
Suzuki
Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Chikusaku, Nagoya, Japan.
Nobuhiro
N
Hanai
Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Chikusaku, Nagoya, Japan.
Yasuhisa
Y
Hasegawa
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D060828:Induction Chemotherapy; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000532:radiotherapy*; D010306:Parotid Gland / Q000528:radiation effects; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D012189:Retrospective Studies; D012449:Safety; D016896:Treatment Outcome; D014987:Xerostomia / Q000209:etiology
Japan; chemoradiotherapy; helical tomotherapy; intensity-modulated radiotherapy; oropharyngeal cancer; prognostic factor; squamous cell carcinoma