title: Radiation therapy for nasopharyngeal carcinoma: the predictive value of interim survival assessment.
abstract: Pretreatment characteristics are suggested as predictive and/or prognostic factors for nasopharyngeal carcinoma (NPC); however, individual tumor radiosensitivities have previously not been considered. As boost planning is recommended for NPC, we performed interim assessments of magnetic resonance (MR) images for boost planning and retrospectively evaluated their predictive value for the survival of NPC patients. Radiation therapy via elective nodal irradiation (median dose: 39.6 Gy) with/without chemotherapy was used to treat 63 NPC patients. Boost irradiation (median total dose: 70 Gy) was performed based on the interim assessment. The largest lymph node (LN) was measured on MR images acquired at the time of interim assessment. The site of first failure was local in 8 (12.7%), regional in 7 (11.1%), and distant in 12 patients (19.0%). All 7 patients with regional failure harbored LNs ≥15 mm at interim assessment. We divided the 63 patients into two groups based on LN size [large (≥15 mm), n = 10 and small (<15 mm), n = 53]. Univariate analysis showed that 5-year overall survival (OS) and cause-specific survival (CSS) rates for large LNs were significantly lower than for small LNs (OS: 12.5% vs 70.5%, P < 0.001 and CSS: 25.0% vs 80.0%, P < 0.001). Multivariate analysis showed that large LNs were a significantly unfavorable factor for both OS (hazard ratio = 4.543, P = 0.002) and CSS (hazard ratio = 6.020, P = 0.001). The results suggest that LN size at interim assessment could predict survival in NPC patients.
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA ryo108@kumamoto-u.ac.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Toya
authors.affiliation: Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Murakami
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Daizo
authors.initials: D
authors.lastname: Murakami
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Matsuyama
authors.affiliation: Department of Radiology, Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Baba
authors.affiliation: Department of Radiology, Saiseikai Kumamoto Hospital, Kumamoto, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishimura
authors.affiliation: Department of Diagnostic Radiology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Semba
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Yumoto
authors.affiliation: Department of Diagnostic Radiology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Natsuo
authors.initials: N
authors.lastname: Oya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D011237:Predictive Value of Tests; D016019:Survival Analysis; D055815:Young Adult
keywords: adaptive radiation therapy; lymph node metastasis; nasopharyngeal carcinoma; predictive factor; radiation therapy; tailored therapy