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During the radiotherapy process, the emergence of set-up errors is nearly inevitable. Because set-up errors were not detected and corrected daily, planned target volumes were formed by expanding the clinical target volume according to each unit's experience. We optimized the margins of clinical and planned target volumes during administration of intensity-modulated radiotherapy for nasopharyngeal carcinoma. A total of 72 patients newly diagnosed with non-metastatic nasopharyngeal carcinoma and treated with Tomotherapy were prospectively enrolled in the study. For each patient, one megavoltage computed tomography scan was obtained after conventional positioning, online correction, and daily tomotherapy delivery. The interfraction set-up errors were determined using a planning CT based on the registered scan. The mean interfraction errors were -2.437±2.0529 mm, 0.0652±2.3844 mm, 0.318±1.8314 mm, and 0.197±1.8721° for the medial-lateral, superior-inferior, and anterior-posterior directions, and the direction of rotation, respectively. The total MPTV in the three directions was 7.53 mm, 1.83 mm, and 2.08 mm, respectively. The 3-mm margins in the superior-inferior and anterior-posterior directions uniformly expanded from the clinical target volume should be sufficient, and the marging in the medial-lateral direction was up to 7.5 mm. These results suggest that personalized MPTV may be adopted for intensity-modulated radiotherapy planning.

// Wang Fangzheng 1, 2, 3, * , Jiang Chuner 4, * , Ye Zhimin 1, 2 , Sun Quanquan 1, 2 , Liu Tongxin 1, 2 , Xu Min 5 , Wu Peng 6 , Long Bin 7 , Masoto Sakamoto 3 , Wang Yuezhen 1, 2 , Yan Fengqin 1, 2 , Fu Zhenfu 1, 2 and Jiang Yangming 8 1 Department of Radiation Oncology, Zhejiang Cancer Hospital, Zhejiang Hangzhou 310022, People’s Republic of China 2 Zhejiang Key Laboratory of Radiation Oncology, Zhejiang Hangzhou 310022, People’s Republic of China 3 Department of Radiology, Japanese Red Cross Fukui Hospital, Fukui 918-8501, Japan 4 Department of Breast Tumor Surgery, Zhejiang Cancer Hospital, Zhejiang Hangzhou 310022, People’s Republic of China 5 Department of Physics, Zhejiang Cancer Hospital, Zhejiang Hangzhou 310022, People’s Republic of China 6 Department of Pathology, Zhejiang Cancer Hospital, Zhejiang Hangzhou 310022, People’s Republic of China 7 Department of Nuclear Medicine, Zhejiang Cancer Hospital, Zhejiang Hangzhou 310022, People’s Republic of China 8 Department of Didital Earth, Institute of Remote Sensing and Didital Earth, CAS, Beijing 100101, People’s Republic of China * These authors have contributed equally to this work Correspondence to: Jiang Yangming, email: jym_wm@126.com Wang Fangzheng, email: wangfz76@126.com Keywords: nasopharyngeal carcinoma, neoadjuvant chemotherapy, cycle, survival outcomes, prognosis Received: July 18, 2017 Accepted: September 21, 2017 Published: October 06, 2017 ABSTRACT Neoadjuvant chemotherapy (NAC) is widely used to treat locoregionally advanced nasopharyngeal carcinoma (NPC). To determine the optimal number of NAC cycles, we assessed the effect of NAC cycle on survival outcomes of locoregionally advanced NPC patients receiving NAC before concurrent chemotherapy and intensity-modulated radiotherapy. Clinical data from 1,188 non-metastatic NPC patients were retrospectively reviewed. All received ≥2 cycles of NAC added to concurrent chemoradiotherapy. Propensity score matching (PSM) was used to identify paired patients according to various covariates. In total, 297 pairs were selected. After a median follow-up time of 57 months (range: 7 to 104 months), the 5-year locoregional relapse-free survival, distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival rates in patients treated with 2 cycles vs. 3 to 4 cycles of NAC were 91.3% vs. 87.2% ( P =0.149), 93.3% vs. 88.5% ( P =0.043), 88.7% vs. 81.7% ( P =0.037), and 94.0% vs. 92.6% ( P =0.266), respectively. On multivariate analysis, 2 cycles of NAC were associated with improved DMFS (hazard ratio, 0.499; P =0.038) and PFS (hazard ratio, 0.585; P =0.049). NAC cycle was an independent prognosticator of DMFS and PFS in univariate and multivariate analyses. Thus, 2 cycles of NAC appear sufficient, as additional cycles were not associated with added survival benefit for locoregionally advanced NPC.

// Wang Fangzheng 1, 2, 3, * , Sun Quanquan 1, 2 , Jiang Chuner 4, * , Wang Lei 1, 2 , Yan Fengqin 1, 2 , Ye Zhimin 1, 2 , Liu Tongxin 1, 2 , Xu Min 5 , Wu Peng 6 , Jiang Haitao 7 , Rihito Aizawa 8 , Masoto Sakamoto 3 , Wang Yuezhen 1, 2 and Fu Zhenfu 1, 2 1 Department of Radiation Oncology, Zhejiang Cancer Hospital, Zhejiang Hangzhou, 310022, People’s Republic of China 2 Zhejiang Key Laboratory of Radiation Oncology, Zhejiang Hangzhou, 310022, People’s Republic of China 3 Department of Radiology, Japanese Red Cross Fukui Hospital, Fukui, 918-8501, Japan 4 Department of Breast Tumor Surgery, Zhejiang Cancer Hospital, Zhejiang Hangzhou, 310022, People’s Republic of China 5 Department of Physics, Zhejiang Cancer Hospital, Zhejiang Hangzhou, 310022, People’s Republic of China 6 Department of Pathology, Zhejiang Cancer Hospital, Zhejiang Hangzhou, 310022, People’s Republic of China 7 Department of Radiology, Zhejiang Cancer Hospital, Zhejiang Hangzhou, 310022, People’s Republic of China 8 Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan * These authors contributed equally to this work Correspondence to: Wang Fangzheng, email: wangfz76@126.com Keywords: nasopharyngeal carcinoma, induction chemotherapy, intensity-modulated radiotherapy, concurrent chemotherapy, toxicity Received: March 20, 2017 Accepted: May 14, 2017 Published: May 27, 2017 ABSTRACT Addition of induction chemotherapy (IC) to concurrent chemoradiotherapy (CC) is an encouraging first-line treatment strategy for patients with locoregionally advanced nasopharyngeal carcinoma (NPC). We evaluated the clinical efficacy and toxicity of addition of gemcitabine plus cisplatin (GP) IC to intensity-modulated radiotherapy (IMRT) and CC for patients with locoregionally advanced NPC. At a median follow-up duration of 48 months (10–59 months), 4-year local relapse-free survival (LRFS) was 86.9%, regional relapse-free survival (RRFS) was 90.6%, distant metastasis-free survival (DMFS) was 79.8%, progression-free survival (PFS) was 77.0%, and overall survival (OS) was 81.9%. Univariate analysis revealed that T stage, N stage, clinical stage, and CC correlated with OS, while N stage and clinical stage correlated with PFS. In multivariate analysis, T4 was a prognostic indicator of poor OS and PFS, and N3 was a prognostic indicator of poor OS. Having received ≥ 2 cycles of IC was prognostic of better RRFS. During IC, grade 3–4 thrombocytopenia occurred in 10 patients, and grade 3–4 leukocytopenia was observed in 16 patients. Two patients developed mild liver dysfunction. These findings indicate that GP-based IC followed by CC has promising efficacy with acceptable toxicities.