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The objective of this study is to identify the risk factors and construct a prediction-score model for distant metastasis (DM) in nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT). A total of 520 nonmetastatic NPC patients were analysed retrospectively. The independent risk factors for DM were tested by multivariate Cox regression analysis. The prediction-score model was established according to the regression coefficient. The median follow-up was 88.4 months. The 5-year DM rate was 15.1%. N2-3, primary tumour volume of nasopharynx (GTVnx) >24.56 cm(3), haemoglobin change after treatment (ΔHGB) >25.8 g/L, albumin-globulin ratio (AGR) ≤1.34, pretreatment neutrophil-lymphocyte ratio (NLR) >2.81 and pretreatment serum lactate dehydrogenase (LDH) >245 U/L were significantly adverse independent predictive factors for DM. Three subgroups were defined based on the prediction-score model: low risk (0-2), intermediate risk (3-4) and high risk (5-8). The 5-year DM rates were 4.6, 21.8 and 50.8%, respectively (P < 0.001). The areas under the curve for DM in the prediction-score model and the UICC/AJCC staging system seventh edition were 0.748 and 0.627, respectively (P < 0.001). The scoring model is useful in evaluating the risk of DM in IMRT-treated NPC patients and guiding future therapeutic trials. Further prospective study is needed.

Background: The optimal model of total dose and fraction size for patients with locally recurrent nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) remains unclear. The authors designed a randomized phase 2 clinical trial to investigate the efficacy of 2 different models, with the objective of determining an optimal model., Methods: Between January 2003 and December 2007, a total of 117 patients with locally recurrent nonmetastatic nasopharyngeal carcinoma were randomized to 2 different models of total dose and fraction size: group A (59 patients) received 60 gray in 27 fractions and group B (58 patients) received 68 gray in 34 fractions. Both groups received 5 daily fractions per week. All patients received IMRT alone., Results: The median follow-up was 25.0 months. The 5-year overall survival in group A was higher than that in group B (44.2% vs 30.3%; P =.06), and the local failure-free survival in group A was slightly lower than that in group B (63.7% vs 71.0%; P =.41). Severe late complications were the main cause of death. The incidences of mucosal necrosis and massive hemorrhage in patients in group B were significantly higher than those among patients in group A at 50.8% versus 28.8% (P =.02) and 31.0% versus 18.6% (P =.12), respectively. Tumor volume (P<.01) and model of total dose and fraction size (P =.03) were found to be significant factors for mucosal necrosis and massive hemorrhage., Conclusions: Appropriately decreasing the total dose and increasing the fraction size can achieve local control similar to that achieved with a higher dose after IMRT; furthermore, it can improve overall survival by significantly reducing the incidence of severe late complications including mucosal necrosis and massive hemorrhage., (© 2014 American Cancer Society.)

Purpose: To report our initial experience on the feasibility, toxicity, and tumor control using intensity-modulated radiotherapy (IMRT) for retreatment of recurrent nasopharyngeal carcinoma (NPC)., Methods and Materials: A total of 49 patients with locoregional recurrent carcinoma in the nasopharynx were treated with IMRT between January 2001 and February 2002 at the Sun Yat-Sen University Cancer Center, Guangzhou, China. The average time to the nasopharyngeal recurrence was 30.2 months after initial conventional RT. The median isocenter dose to the nasopharynx was 70 Gy (range 60.9-78.0) for the initial conventional RT. All patients were restaged at the time of recurrence according to the 1992 Fuzhou, China staging system on NPC. The number of patients with Stage I, II, III and IV disease was 4, 9, 10, and 26, respectively. T1, T2, T3, and T4 disease was found in 4, 9, 11, and 25 patients, respectively. N0, N1, N2, and N3 disease was found in 46, 2, 0, and 1 patient, respectively. Invasion of the nasal cavity, maxillary sinus, ethmoid sinus, sphenoid sinus, and cavernous sinus and erosion of the base of the skull was found in 8, 1, 3, 8, 15, and 20 patients, respectively. The gross tumor volume (GTV) was contoured according to the International Commission on Radiation Units and Measurements (ICRU) Report 62 guidelines. The critical structures were contoured, and the doses to critical structures were constrained according to ICRU 50 guidelines. The GTV in the nasopharynx and positive lymph nodes in the neck received a prescription dose of 68-70 Gy and 60 Gy, respectively. All patients received full-course IMRT. Three patients who had positive lymph nodes were treated with five to six courses of chemotherapy (cisplatin + 5-fluorouracil) after IMRT., Results: The treatment plans showed that the percentage of GTV receiving 95% of the prescribed dose (V(95-GTV)) was 98.5%, and the dose encompassing 95% of GTV (D(95-GTV)) was 68.1 Gy in the nasopharynx. The mean dose to the GTV was 71.4 Gy. The average doses of the surrounding critical structures were much lower than the tolerable thresholds. At a median follow-up of 9 months (range 3-13), the locoregional control rate was 100%. Three cases (6.1%) of locoregional residual disease were seen at the completion of IMRT, but had achieved a complete response at follow-up. Three patients developed metastases at a distant site: two in the bone and one in the liver and lung at 13 months follow-up. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. Tumor necrosis was seen toward the end of IMRT in 14 patients (28.6%)., Conclusion: The improvement in tumor target coverage and significant sparing of adjacent critical structures allow the feasibility of IMRT as a retreatment option for recurrent NPC after initial conventional RT. This is the first large series using IMRT to reirradiate local recurrent NPC after initial RT failed. The treatment-related toxicity profile was acceptable. The initial tumor response/local control was also very encouraging. In contrast to primary NPC, recurrent NPC reirradiated with high-dose IMRT led to the shedding of tumor necrotic tissue toward the end of RT. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome.

Objective: To evaluate the feasibility, toxicity and tumor control of intensity modulated radiation therapy (IMRT) for recurrent nasopharyngeal carcinoma., Methods: Fourty-nine patients (Karnofsky performance status (KPS) >or= 80) with local-regional recurrence in the nasopharynx were treated with full course IMRT. Three patients with cervical lymph node metastasis (N1 2 and N3 1) were further supplemented with 5 to 6 courses of chemotherapy (Cisplatin + 5-Fu) after IMRT., Results: The results of treatment plan showed that the mean dose of covering gross tumor volume (GTV) (D(95)) in the nasopharynx was 68.09 Gy and the mean volume of GTV (V(95)) receiving the 95% dose was 98.46%. The mean dose of GTV, clinical target volume CTV1 and CTV2 in the targets were 71.40 Gy, 63.63 Gy and 59.81 Gy. The median follow-up time was 9 months (range 3 to 16 months). The local-regional progression-free survival was 100% with local-regional residual disease in 3 (6.1%) cases but was complicated with nasopharyngeal mucosa necrosis in 14 (28.6%) cases after IMRT., Conclusion: Intensity modulated radiation therapy, as a re-treatment option for recurrent nasopharyngeal carcinoma, is able to improve the tumor target coverage and spare the adjacent critical structures. As high dose IMRT can result in radio-necrosis of nasopharyngeal mucosa, the prescription dose of GTV should be suitably decreased to 60 - 65 Gy.