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Background: This study aimed to evaluate the long-term outcome and toxicities in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated by concurrent chemoradiotherapy (CCRT) with/without adding cetuximab.Methods: A total of 62 patients treated with CCRT plus cetuximab were matched with 124 patients treated with CCRT alone by age, sex, pathological type, T category, N category, disease stage, radiotherapy (RT) technique, Epstein-Barr virus (EBV) DNA levels, and Eastern Cooperative Oncology Group (ECOG). Overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method and log-rank test. Treatment toxicities were clarified and compared between two groups.Results: A total of 186 well-balanced stage II to IV NPC patients were retrospectively analyzed (median follow-up, 76 months). Compared to CCRT alone, adding cetuximab resulted in more grade 3 to 4 radiation mucositis (51.6% vs. 23.4%; P < 0.001). No differences were found between the CCRT + cetuximab group and the CCRT group in 5-year OS (89.7% vs. 90.7%, P = 0.386), 3-year PFS (83.9% vs. 88.7%, P = 0.115), the 3-year LRFS (95.0% vs. 96.7%, P = 0.695), and the 3-year DMFS (88.4% vs 91.9%, P = 0.068). Advanced disease stage was the independent prognostic factor predicting poorer OS and PFS.Conclusion: Adding cetuximab to CCRT did not significantly improve benefits in survival in stage II to IV NPC and exacerbated acute mucositis and acneiform rash. Further investigations are warranted. [ABSTRACT FROM AUTHOR]

Background: To compare the survival outcomes and acute toxicities of concurrent chemoradiotherapy (CCRT), induction chemotherapy (IC) plus radiotherapy (RT), and IC plus CCRT in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated using intensity-modulated radiotherapy (IMRT).Methods: Patients with stage III-IVB NPC who were treated with IMRT between 2009 and 2012 at a single institution were retrospectively reviewed. The induction regimens included PF (cisplatin and fluorouracil) and TP (docetaxel and cisplatin) every 3 weeks for 2-3 cycles; the concurrent regimen was cisplatin every three weeks for 2-3 cycles. A propensity score matching method was used to match patients from each group in a 1:1:1 ratio.Results: In total, 147 eligible patients were propensity-matched, with 49 patients in each treatment group. The median follow-up duration was 38.5 months (range, 4.5 - 56 months). The 3-year disease-free survival, overall survival, distant metastasis-free survival, and locoregional relapse-free survival rates were 82.1%, 92.8%, 87%, and 90.4% in the CCRT group; 86.3%, 91.0%, 91.6%, and 94.4% in the IC plus RT group; and 87.8%, 95.8%, 93.8%, and 93.9% in the IC plus CCRT group, respectively. No statistically significant survival differences were observed between the three treatment groups in either univariate or multivariate analyses. The incidence of grade 3-4 acute toxicities was similar among groups.Conclusions: This study suggests that CCRT, IC plus RT, and IC plus CCRT are similarly efficacious treatment strategies for patients with locoregionally advanced NPC treated using IMRT; however, long-term, large-scale randomized trials are required to confirm these findings. [ABSTRACT FROM AUTHOR]

Background: To identify the radiation volume effect and significant dosimetric parameters for temporal lobe injury (TLI) and determine the radiation dose tolerance of the temporal lobe (TL) in nasopharyngeal carcinoma (NPC) patients treated with intensity modulated radiation therapy (IMRT).Methods: Twenty NPC patients with magnetic resonance imaging (MRI)-diagnosed unilateral TLI were reviewed. Dose-volume data was retrospectively analyzed.Results: Paired samples t-tests showed all dosimetric parameters significantly correlated with TLI, except the TL volume (TLV) and V₇₅ (the TLV that received ≥75 Gy, P = 0.73 and 0.22, respectively). Receiver operating characteristic (ROC) curves showed V₁₀ and V₂₀ (P = 0.552 and 0.11, respectively) were the only non-significant predictors from V₁₀ to V₇₀ for TLI. D(0.5cc) (dose to 0.5 ml of the TLV) was an independent predictor for TLI (P < 0.001) in multivariate analysis; the area under the ROC curve for D(0.5cc) was 0.843 (P < 0.001), and the cutoff point 69 Gy was deemed as the radiation dose limit. The distribution of high dose 'hot spot' regions and the location of TLI were consistent.Conclusions: A D0.5cc of 69 Gy may be the dose tolerance of the TL. The risk of TLI was highly dependent on high dose 'hot spots' in the TL; physicians should be cautious of such 'hot spots' in the TL during IMRT treatment plan optimization, review and approval. [ABSTRACT FROM AUTHOR]

Background: This prospective study was conducted to evaluate inter- and intra-fraction errors in nasopharyngeal carcinoma (NPC) patients undergoing volumetric modulated arc therapy (VMAT) using cone-beam computed tomography (CBCT) and to thus obtain planning target volume (PTV) margins to effectively guide treatment in the future. Methods: Fifteen NPC patients scheduled to undergo VMAT were prospectively enrolled in the study. For each patient, three CBCT scans were obtained; one after daily conventional positioning, one after online correction with 2 mm tolerance and one after 1 week of VMAT delivery. The scans were registered to the planning CT to determine the inter- and intra-fraction errors. Patient positioning errors were analyzed for time trends over the course of radiotherapy. PTV margins were calculated from the systematic (∑) and random (σ) errors. Results: The average absolute values of the pre-correction, post-correction and intra-fraction errors (in order) were 1.1, 0.6 and 0.4 mm in the medial-lateral (ML) direction, 1.2, 0.7 and 0.5 mm in the superior-inferior (SI) direction and 1.1, 0.7 and 0.5 mm in the anterior-posterior (AP) direction. The corresponding ∑ were 1.0-1.4 mm, 0.4-0.5 mm and 0.2-0.4 mm, while the corresponding s were 0.7-0.8 mm, 0.6-0.7 mm and 0.5-0.6 mm. With time, gradual increases in both the inter- and intra-fraction three-dimensional displacements were observed (P = 0.019 and P = 0.044, respectively). The total PTV margins accounting for pre-correction and intra-fraction errors were 3.4-4.1 mm and those accounting for post-correction and intra-fraction errors were 1.7-2.2 mm. Conclusions: CBCT is an effective modality to evaluate and improve the accuracy of VMAT in NPC patients. Inter- and intra-fraction three-dimensional displacements increased as a function of time during the course of radiotherapy. In our institution, we recommend a PTV margin of 5 mm for NPC patients undergoing VMAT without CBCT and 3 mm for those treated with rigorous daily CBCT scans. [ABSTRACT FROM AUTHOR]