Normal Tissue Complication Probability Model for Radiation-induced Temporal Lobe Injury after Intensity-modulated Radiation Therapy for Nasopharyngeal Carcinoma.

PURPOSE: To identify predictors for the development of temporal lobe injury (TLI) after intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma. MATERIALS AND METHODS: Data in 351 patients with nasopharyngeal carcinoma treated with IMRT were reviewed retrospectively according to institutional ethics committee approval. Clinical factors associated with TLI were analyzed. Dose-volume histograms for 550 evaluable temporal lobes were analyzed, and the predictive value of therapy-associated and patient-associated factors for the occurrence of TLI was evaluated. Survival curves were depicted by using the Kaplan-Meier method and compared by using the log-rank test. Logistic regression analysis was used for multivariate analyses. RESULTS: Median follow-up was 76 months (range, 6-100 months). Twenty-nine of 351 patients (8.3%) developed TLI; 21 patients had unilateral TLI, and eight had bilateral TLI. Median latency from IMRT until first TLI was 33 months (range, 12-83 months) among patients with TLI. The actuarial TLI-free survival rates were 94.4% and 91.3% at 3 and 5 years after radiation therapy, respectively. Logistic regression analysis demonstrated that dose delivered to a 1-cm(3) volume of the temporal lobe (D1cc) was the only independent predictor for TLI. The biologically equivalent tolerance doses at 2 Gy for a 5% and 50% probability of developing TLI were 62.83-Gy equivalents (95% confidence interval: 59.68, 65.97) and 77.58-Gy equivalents (95% confidence interval: 74.85, 80.32), respectively. CONCLUSION: D1cc is predictive for radiation-induced TLI, suggesting that delivery of a high dose of radiation to a small volume of the temporal lobe is unsafe. A D1cc of 62.83 Gy by using a correction formula for varying fraction size may be the dose tolerance of the temporal lobe.

Impact of primary tumor volume and location on the prognosis of patients with locally recurrent nasopharyngeal carcinoma.

INTRODUCTION: The properties of a tumor itself were considered the main factors determining the survival of patients with locally recurrent nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT). However, recurrent tumors were mainly evaluated by using the American Joint Committee on Cancer staging system, which was modeled on primary tumors and did not incorporate the tumor volume. This study aimed to investigate the prognostic values of the primary tumor location and tumor volume, and to determine whether evaluating these parameters could improve the current staging system. METHODS: Magnetic resonance (MR) images for 229 patients with locally recurrent NPC who underwent IMRT were analyzed retrospectively. RESULTS: The skull base, parapharyngeal space, and intracranial cavity were the most common sites of tumors. There was a difference in the survival between patients with T1 and T2 diseases (77.6% vs. 50.0%, P<0.01) and those with T3 and T4 diseases (33.0% vs. 18.0%, P=0.04) but no difference between patients with T2 and T3 diseases (50.0% vs. 33.0%, P=0.18). Patients with a tumor volume≤38 cm3 had a significantly higher survival rate compared with those with a tumor volume>38 cm3 (48.7% vs. 15.2%, P<0.01). CONCLUSIONS: A new staging system has been proposed, with T3 tumors being down-staged to T2 and with the tumor volume being incorporated into the staging, which may lead to an improved evaluation of these tumors. This new system can be used to guide the treatment strategy for different risk groups of recurrent NPC.

Effect of total dose and fraction size on survival of patients with locally recurrent nasopharyngeal carcinoma treated with intensity-modulated radiotherapy: a phase 2, single-center, randomized controlled trial.

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.

Intensity-modulated radiotherapy for stage IVA/IVB nasopharyngeal carcinoma: clinical outcomes and patterns of failure in an endemic area in China.

PURPOSE: The purpose of this study was to analyze the mode of relapse patterns and survival of 209 patients with stage IVA and IVB nasopharyngeal carcinoma (NPC). PATIENTS AND MATERIALS: A total of 209 patients who underwent magnetic resonance imaging (MRI) and were subsequently histologically diagnosed with nondisseminated stage IV NPC received intensity-modulated radiotherapy (IMRT) as their primary treatment and were included in this retrospective study. RESULTS: Median follow-up time was 65 months (range, 3-108 months). The 5-year overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates for patients with stage IVA and stage IVB NPC were 72.7 vs. 60.0 % (p = 0.319), 62.9 vs. 51.3 % (p = 0.070), 82.9 vs. 93.1 % (p = 0.070), 82.9 vs. 82.9 % (p = 0.897), 76.4 vs. 58.5 % (p = 0.003), respectively. Age older than 44 years was found to be a statistically significant adverse independent prognostic factor for OS. Patients with advanced N status had worse OS, DFS, and DMFS rates. Patients with a primary gross tumor volume (GTV-P) ≥ 55.11 ml had worse OS, DFS, and LRRFS rates. CONCLUSION: The results of treating stage IVA NPC with IMRT were excellent. Distant metastasis remains the most difficult treatment challenge for patients with stage IVA and IVB NPC, and more effective systemic chemotherapy should be explored.

The Value of Cervical Node Features in Predicting Long-Term Survival of Nasopharyngeal Carcinoma in the Intensity-Modulated Radiotherapy Era.

OBJECTIVE: To investigate the prognostic value of cervical node features in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT) and build a prognostic nomogram to predict the long-term survival. METHODS: In this study, 1752 patients after IMRT from 2008 to 2011 were recruited. The clinical and laboratory characteristics and the nodal features including the nodal number, maximum dimension diameter, extranodal extension (ENE), and cervical node necrosis (CNN) were retrospective analyzed. Univariate Cox and multivariate proportional hazard regression models were used to test the prognostic value of nodal features. Prognostic nomograms were established to predict survival. RESULTS: The 10-year distant metastases-free survival (DMFS) and disease-specific survival (DSS) rates were 86.5% and 80.8%, respectively. Multivariate analysis showed that age, sex, lactate dehydrogenase (LDH), CNN, ENE, T stage, and N stage were independent factors for DSS. Two nomograms-nomogram A (without nodal features) and nomogram B (with nodal features)-were built. The calibration curve for the probability of DSS showed good agreement between prediction by nomogram and the actual observation. The C-index of nomogram B was higher than that for nomogram A in predicting DSS (0.708 vs 0.676, P<0.01). CONCLUSION: The nodal features including ENE and CNN were negative prognostic factors for NPC, and the prognostic nomogram incorporating the nodal features was more accurate in predicting survival than the nomogram without nodal features.

Development of a Comorbidity-Based Nomogram to Predict Survival After Salvage Reirradiation of Locally Recurrent Nasopharyngeal Carcinoma in the Intensity-Modulated Radiotherapy Era.

PURPOSE: To assess the impact of comorbidity on treatment outcomes in patients with locally recurrent nasopharyngeal carcinoma (lrNPC) using intensity-modulated radiotherapy (IMRT) and to develop a nomogram that combines prognostic factors to predict clinical outcome and guide individual treatment. METHODS: This was a retrospective analysis of patients with lrNPC who were reirradiated with IMRT between 2003 and 2014. Comorbidity was evaluated by Adult Comorbidity Evaluation-27 grading (ACE-27). The significant prognostic factors (P < 0.05) by multivariate analysis using the Cox regression model were adopted into the nomogram model. Harrell concordance index (C-index) calibration curves were applied to assess this model. RESULTS: Between 2003 and 2014, 469 lrNPC patients treated in our institution were enrolled. Significant comorbidity (moderate or severe grade) was present in 17.1% of patients by ACE-27. Patients with no or mild comorbidity had a 5-year overall survival (OS) rate of 36.2 versus 20.0% among those with comorbidity of moderate or severe grade (P < 0.0001). The chemotherapy used was not significantly different in patients with lrNPC (P > 0.05). For the rT3-4 patients, the 5-year OS rate in the chemotherapy + radiation therapy (RT) group was 30.0 versus 16.7% for RT only (P = 0.005). The rT3-4 patients with no or mild comorbidity were associated with a higher 5-year OS rate in the chemotherapy + RT group than in the RT only group (32.1 and 17.1%, respectively; P=0.003). However, for the rT3-4 patients with a comorbidity (moderate or severe grade), the 5-year OS rate in the chemotherapy + RT group vs. RT alone was not significantly different (15.7 vs. 15.0%, respectively; p > 0.05). Eight independent prognostic factors identified from multivariable analysis were fitted into a nomogram, including comorbidity. The C-index of the nomogram was 0.715. The area under curves (AUCs) for the prediction of 1-, 3-, and 5-year overall survival were 0.770, 0.764, and 0.780, respectively. CONCLUSION: Comorbidity is among eight important prognostic factors for patients undergoing reirradiation. We developed a nomogram for lrNPC patients to predict the probability of death after reirradiation and guide individualized management.

Prognostic model and optimal treatment for patients with stage IVc nasopharyngeal carcinoma at diagnosis.

The treatment for patients with stage IVc nasopharyngeal carcinoma (NPC) at diagnosis was still controversial. In this study, we tried to build a prognostic score model and optimize the treatment for the patients. The prognostic model was based on the primary cohort involving 289 patients from 2002 to 2011 and the validation involving another 156 patients from 2012 to 2015.The prognostic model was built based on the hazard ratios of significant prognostic factors for overall survival (OS). By multivariate analysis, factors associated with poor OS were Karnofsky performance score ≤70, liver metastases, multiple-organ metastases, ≥2 metastatic lesions, lactate dehydrogenase >245 IU/I and poor response to chemotherapy (all P < 0.01). Based on these prognostic factors, patients were divided into the low-risk (0-2 points), intermediate-risk (3-6 points) and high-risk (≥7 points) groups. Five-year OS rates for the low-, intermediate- and high-risk groups were 49.3%, 9.7% and 0.0%, respectively (P < 0.01). Furthermore, loco-regional radiotherapy was associated with significantly better OS in low- and intermediate-risk patients, but not in high-risk patients. These results demonstrated that the prognostic score model based on six negative factors can effectively predict OS in patients with stage IVc NPC at diagnosis. Loco-regional radiotherapy may be beneficial for low- and intermediate-risk patients, but not for high-risk patients.

Long-term outcome and pattern of failure for patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy.

PURPOSE: To analyze the long-term outcome and pattern of failure for patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: Patients with NPC after IMRT from 2001 to 2008 were recruited (n = 865). Clinical features, laboratory data, and treatments were collected. RESULTS: The 10-year local recurrence-free survival, distant metastasis-free survival, and disease-specific survival (DSS) were 92.0%, 83.4%, and 78.6%, respectively. A total of 209 patients died: 59% of whom died from distant metastasis. The 10-year DSS was higher in patients who received chemoradiotherapy than those who received IMRT alone for patients with high-risk stage III disease, while there was no survival difference for patients with stage II and low-risk stage III disease. CONCLUSIONS: IMRT provides satisfactory long-term survival for patients with NPC. Distant metastasis has been the most common reason for failure. Adding chemotherapy did not improve survival in patients with stage II and low-risk stage III disease.

Clinical characteristics and prognostic value of pre-retreatment plasma epstein-barr virus DNA in locoregional recurrent nasopharyngeal carcinoma.

PURPOSE: To define the clinical characteristics and prognostic value of pre-retreatment plasma Epstein-Barr virus (EBV) DNA, we investigated EBV status in locoregional recurrent nasopharyngeal carcinoma (lrNPC) patients. METHODS: Between April 2008 and August 2016, the data of patients with nonmetastatic lrNPC were retrospectively reviewed. The survival indexes of patients between different pre-retreatment EBV status groups were compared. RESULTS: A total of 401 patients with nonmetastatic lrNPC were enrolled, and 197 (49.1%) patients had detectable pre-retreatment plasma EBV DNA. Treatment included radiotherapy alone (n = 37 patients), surgery alone (n = 105), radiotherapy (n = 208), surgery combined with radiotherapy (n = 20), chemotherapy and targeted therapy (n = 31). Median follow-up was 32 months. The 3-year locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and overall survival (OS) rates for the entire cohort were 64.8%, 89.4%, and 58.8%, respectively. The estimated 3-year LRRFS, DMFS, and OS rates for the pre EBV-positive group vs the pre EBV-negative group were 54.2% vs 75.0% (P < 0.001), 86.6% vs 91.9% (P = 0.05), 51.6% vs 65.9% (P = 0.01), respectively. Among patients in the clinical stage rI/II, there were 17 patients in the radiotherapy alone group and 49 patients in the surgery alone group. And there was no significant difference in overall survival between radiotherapy and surgery, even among the different pre-EBV statuses (P > 0.05). In terms of long-term toxic and side effects, the incidence of radioactive temporal lobe injury in the radiotherapy group was higher than that in the surgery group (35.3% vs 8.2%, P < 0.001), and no statistically significant difference was found in other long-term toxic and side effects. CONCLUSIONS: The positive rate of pre-retreatment plasma EBV DNA in lrNPC is lower than primary NPC. The prognosis of EBV DNA negative group is better than positive group. For locally early-stage lrNPC, regardless of EBV DNA status, radiotherapy and surgery are available options and both can achieve better long-term survival.

Prognostic Model for Stratification of Radioresistant Nasopharynx Carcinoma to Curative Salvage Radiotherapy.

Purpose To investigate for a prognostic index (PI) to personalize recommendations for salvage intensity-modulated radiotherapy (IMRT) in patients with locally recurrent nasopharyngeal carcinoma (lrNPC). Methods Patients with lrNPC from two academic institutions (Sun Yat-Sen University Cancer Center [SYSUCC-A; n = 251 (training cohort)] and National Cancer Centre Singapore [NCCS; n = 114] and SYSUCC-B [n = 193 (validation cohorts)]) underwent salvage treatment with IMRT from 2001 to 2015. Primary and secondary clinical end points were overall survival (OS) and grade 5 toxicity-free rate (G5-TFR), respectively. Covariate inclusion to the PIs was qualified by a multivariable two-sided P < .05. Discrimination and calibration of the PIs were assessed. Results The primary PI comprised covariates that were adversely associated with OS in the training cohort (gross tumor volumerecurrence hazard ratio [HR], 1.01/mL increase [ P < .001], agerecurrence HR, 1.02/year increase [ P = .008]; repeat IMRT equivalent dose in 2-Gy fractions [EQD2] ≥ 68 Gy HR, 1.42 [ P = .03]; prior radiotherapy-induced grade ≥ 3 toxicities HR, 1.90 [ P = .001]; recurrent tumor [rT]-category 3 to 4 HR, 1.96 [ P = .005]), in ascending order of weight. Discrimination of the PI for OS was comparable between training and both validation cohorts (Harrell's C = 0.71 [SYSUCC-A], 0.72 [NCCS], and 0.69 [SYSUCC-B]); discretization by using a fixed PI score cutoff of 252 determined from the training data set yielded low- and high-risk subgroups with disparate OS in the validation cohorts (NCCS HR, 3.09 [95% CI, 1.95 to 4.89]; SYSUCC-B HR, 3.80 [95% CI, 2.55 to 5.66]). Our five-factor PI predicted OS and G5-TFR (predicted v observed 36-month OS and G5-TFR, 22% v 15% and 38% v 44% for high-risk NCCS and 26% v 31% and 45% v 46% for high-risk SYSUCC-B). Conclusion We present a validated PI for robust clinical stratification of radioresistant NPC. Low-risk patients represent ideal candidates for curative repeat IMRT, whereas novel clinical trials are needed in the unfavorable high-risk subgroup.

The challenge in treating locally recurrent T3-4 nasopharyngeal carcinoma: the survival benefit and severe late toxicities of re-irradiation with intensity-modulated radiotherapy.

BACKGROUND: Effective treatments for patients with advanced locally recurrent nasopharyngeal carcinoma (NPC) are limited. This investigation was to determine the potential benefits from re-irradiation by intensity-modulated radiotherapy (IMRT) on survival and the effects of severe late toxicities. METHODS: A retrospective study was conducted in 245 patients diagnosed with locally recurrent T3-T4 NPC who had undergone re-irradiation with IMRT. Follow-up data was colletedand factors associated with survival and severe late toxicities were analyzed. RESULTS: The 5-year local-regional failure-free survival, distant failure-free survival and overall survival rates were 60.9%, 78.3% and 27.5%, respectively. The presence of severe late complications, recurrent T4 disease and gross tumor volume >30 cm3 were associated with poor survival. The incidences of mucosal necrosis, temporal lobe necrosis, cranial neuropathy and trismus were 22.0%, 14.6%, 27.0% and 14.6% respectively. CONCLUSIONS: Re-irradiation with IMRT is an effective choice in patients with locally recurrent T3-T4 NPC. However, the survival benefits can be partly offset by severe late complications and optimum treatments in these patients remain a challenge.

Long-term survival and late complications in intensity-modulated radiotherapy of locally recurrent T1 to T2 nasopharyngeal carcinoma.

BACKGROUND: We investigated the feasibility of reirradiation with intensity-modulated radiotherapy (IMRT) for recurrent T1 to T2 nasopharyngeal carcinoma (NPC) by assessing long-term survival and late complication rates. METHODS: Sixty patients who had been previously irradiated were diagnosed with locally recurrent T1 to T2 NPC and underwent reirradiation with IMRT. Severe radiation toxicities were assessed. RESULTS: The median follow-up time was 40.0 months. The 5-year local failure-free survival (LFFS), distant failure-free survival (DFFS), and overall survival (OS) rates were 85.7%, 96.1%, and 67.2%, respectively. Independent prognostic factors included primary gross tumor volume >20 cm and the presence of significant complications. The most common severe complications were headache (31.6%), mucosal necrosis (30.0%), cranial neuropathy (25.0%), and temporal lobe necrosis (21.6%). Thirty-nine patients (65.0%) developed at least one severe complication and 18 patients died as a result. CONCLUSION: Excellent disease control can be achieved by reirradiation with IMRT for recurrent T1 to T2 NPC. However, the main challenge remains severe late complications.

Retrospective analysis of 234 nasopharyngeal carcinoma patients with distant metastasis at initial diagnosis: therapeutic approaches and prognostic factors.

PURPOSE: The purpose of this retrospective study was to identify the independent prognostic factors and optimize the treatment for nasopharyngeal carcinoma (NPC) patients with distant metastasis at initial diagnosis. METHODS: A total of 234 patients referred between January 2001 and December 2010 were retrospectively analyzed. Among the 234 patients, 94 patients received chemotherapy alone (CT), and 140 patients received chemoradiotherapy (CRT). Clinical features, laboratory parameters and treatment modality were examined with univariate and multivariate analyses. RESULTS: The median overall survival (OS) time was 22 months (range, 2-125 months), and the 1-year, 2-year, 3-year overall survival rates were 82.2%, 51.3% and 34.1%. The overall response and disease control rates of metastatic lesions after chemotherapy were 56.0% and 89.8%. The factors associated with poor response were karnofsky performance score (KPS) <80, liver metastasis, lactate dehydrogenase (LDH)>245 IU/L, and number of chemotherapy cycles <4. The 3-year OS of patients receiving CRT was higher than those receiving CT alone (48.2% vs. 12.4%, p<0.001). Subgroup analysis showed that significantly improved survival was also achieved by radiotherapy of the primary tumor in patients who achieved complete remission (CR)/partial remission (PR) or stable disease (SD) of metastatic lesions after chemotherapy. Significant independent prognostic factors of OS were KPS, liver metastasis, levels of LDH, and multiple metastases. Treatment modality, response to chemotherapy and chemotherapy cycles were also associated with OS. CONCLUSION: A combination of radiotherapy and chemotherapy seems to have survival benefits for selected patients with distant metastases at initial diagnosis. Clinical and laboratory characteristics can help to guide treatment selection. Prospective randomized studies are needed to confirm the result.

Comparative study on prophylactic irradiation to the whole neck and to the upper neck for patients with neck lymph node-negative nasopharyngeal carcinoma.

BACKGROUND: The purpose of this study was to investigate the prophylactic irradiation volume to neck drainage areas for patients with N0 classification nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT). METHODS: From January 2003 to October 2008, 270 patients with N0 classification (American Joint Committee on Cancer [AJCC] 2002 staging system) NPC who had undergone IMRT were retrospectively analyzed. Among all the patients, 171 patients received prophylactic upper-neck irradiation, and 99 patients received prophylactic whole-neck irradiation. RESULTS: At a median follow-up of 65.1 months (range, 4-106 months). The 5-year overall survival (OS), nodal recurrence-free survival (NRFS), and distant metastasis-free survival (DMFS) rates of the upper neck group and the whole neck group were 93.6% vs 90.9% (p = .553), 99.4% vs 99.0% (p = .278), and 98.8% vs 94.9% (p = .128), respectively. A total of 3 neck recurrences were found, including 2 from the whole neck group and 1 from the upper neck group. The latter (0.6%) was an out-of-field recurrence. CONCLUSION: Prophylactic irradiation to the upper neck (levels II, III, and VA) may be feasible for patients with neck lymph node-negative NPC.

Prognostic factors in nasopharyngeal carcinoma with synchronous liver metastasis: a retrospective study for the management of treatment.

PURPOSE: To retrospectively analyze the prognosis of patients with nasopharyngeal carcinoma (NPC) initially presenting with liver metastasis, in order to identify independent prognostic factors to facilitate management of treatment. METHODS: Eighty-five patients with untreated NPC and synchronous liver metastasis, initially diagnosed between January 2000 and December 2009, were selected for this retrospective study. Seventy-eight received systemic chemotherapy, 32 underwent subsequent radiotherapy of the primary tumor, and 18 received local therapy for metastatic lesions. Clinical features, laboratory parameters and treatment modalities were compared by univariate and multivariate analyses. RESULTS: The median survival time was 19.0 months and the 3-year overall survival rate was 14.1%. The overall response and disease control rates were 70.4% and 86.4%, respectively. Significant predictors of short survival were KPS ≤ 70 (P = 0.03), serum lactate dehydrogenase levels >245 IU/l (P = 0.01) and poor response to chemotherapy (P < 0.01). In contrast, significantly longer survival rates were achieved by patients having at least six chemotherapy cycles compared to those receiving <6 cycles (3-year OS: 18.3% vs. 7.1%; P < 0.01), and patients receiving radiotherapy of the primary tumor following complete or partial response to chemotherapy (3-year OS: 30.8% vs. 3.8%, P < 0.01). CONCLUSIONS: Five key independent factors were identified and sub-classified as potential prognostic indicators for NPC with liver metastases. Progressive treatments of systemic chemotherapy and radiotherapy at the primary tumor could prolong survival in the subset of patients having fewer negative prognosticators.