Comparative Study between Patients Treated with Conventional Radiotherapy and IMRT with Chemotherapy for Stage III - IVA Nasopharyngeal Carcinoma: A Single Institution Retrospective Report

Introduction: Nasopharyngeal carcinomas are the most radiation-sensitive tumours, and radiotherapy alone provides better local control. Objectives: To evaluate the clinical efficacy and acute and late toxicities of two different treatment regimens for locally advanced nasopharyngeal carcinoma. Methods: From 2014 to 2017, 150 cases of stage III and 68 cases of stage IVA nasopharyngeal carcinoma were treated. Of these, 137 received conventional radiotherapy plus chemotherapy, and 81 received intensity-modulated radiotherapy plus chemotherapy. Chemotherapy was given either as induction, concurrent or adjuvant therapy. Survival rates were calculated according to Kaplan Meier and compared with the Log-rank test. The RTOG or EORTC criteria were used to assess acute and late toxicities. Results: The median follow-up time was 21.5 months, and the 2-year locoregional relapse-free survival, distant metastases-free survival, and overall survival rates in the conventional radiotherapy plus chemotherapy group were 76%, 71% and 77%, respectively;in the intensity-modulated radiotherapy plus chemotherapy group, they were 97%, 84%, and 100%, respectively. The difference in survival between the two groups was significant (χ2 = 5.06, P = 0.028). The incidence of grade 2 and 3 xerostomia one year after radiotherapy was 45.1% and 30.9% versus 33.3% and 0%. Conclusion: Compared with conventional radiotherapy plus chemotherapy, intensity-modulated radiotherapy plus chemotherapy offers better locoregional relapse-free survival and overall survival in patients with stage III and IVA nasopharyngeal carcinoma, and may significantly reduce the occurrence of radiation-induced xerostomia.

Clinical Analysis of Xerostomia in Patients with Nasopharyngeal Carcinoma after Radiation Therapy

Objective: To investigate the severity of xerostomia and its impact on the quality of life in patients with nasopharyngeal carcinoma after conventional radiation therapy. Methods: One hundred and thirty-six patients with nasopharyngeal carcinoma, treated by conventional radiation therapy in Cancer Center, Sun Yat-sen University, were surveyed by interview at the outpatient department. A questionnaire and a visual analog scale (VAS) were used to analyze xerostomia and xerostomia-related problems. Results: Of 136 patints, 73.5% experienced a moderate to severe degree of xerostomia; 82.4% had to sip water to facilitate speech; 92.6% had to sip water to facilitate chewing and swallowing; 91.2% changed their feeding pattern (eating only mashed food); 61.3% had to wake up to drink water because of dry mouth; 75.0% had dental lesions to varying degrees. Conclusion: 73.5% of the patients with nasopharyngeal carcinoma after conventional radiation therapy experienced a moderate to severe degree of xerostomia. Xerostomia has a significant impact on the patient's speech, deglutition, and sleep, and can increase the morbidity of the dental diseases.

Prognostic factors and failure patterns in non-metastatic nasopharyngeal carcinoma after intensity-modulated radiotherapy

Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy

Background: Gross target volume of primary tumor(GTV?P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma(NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity?modulated radiotherapy(IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to ind a suitable cut?of value of GTV?P for prognosis prediction.Methods: Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver oper?ating characteristic(ROC) curves were used to identify the cut?of values of GTV?P for the prediction of diferent end?points [overall survival(OS), local relapse?free survival(LRFS), distant metastasis?free survival(DMFS), and disease?free survival(DFS)] and to test the prognostic value of GTV?P when compared with that of the American Joint Committee on Cancer T staging system.Results: The 358 patients with locally advanced NPC were divided into two groups by the cut?of value of GTV?P as determined using ROC curves: 219(61.2%) patients with GTV?P ≤46.4 mL and 139(38.8%) with GTV?P >46.4 mL. The 3?year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV?P ≤46.4 mL than in those with GTV?P > 46.4 mL(all P < 0.05). Multivariate analysis indicated that GTV?P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve veriied that the predictive ability of GTV?P was superior to that of T category(P < 0.001). The cut?of values of GTV?P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.Conclusion: In patients with locally advanced NPC, GTV?P >46.4 mL is an independent unfavorable prognostic indi?cator for survival after IMRT, with a prognostic value superior to that of T category.

Radiotherapy with neoadjuvant chemotherapy versus concurrent chemoradiotherapy for ascending-type nasopharyngeal carcinoma:a retrospective comparison of toxicity and prognosis

Background:In the era of intensity?modulated radiotherapy(IMRT),the role of neoadjuvant chemotherapy(NACT)in treating ascending?type nasopharyngeal carcinoma(NPC)is under?evaluated.This study was to compare the efficacy of NACT followed by IMRT(NACT+RT)with the efficacy of concurrent chemoradiotherapy(CCRT)on ascending?type NPC.Methods:Clinical data of 214 patients with ascending?type NPC treated with NACT+RT or CCRT between Decem?ber 2009 and July 2011 were analyzed.Of the 214 patients,98 were treated with NACT followed by IMRT,and 116 were treated with CCRT.The survival rates were assessed using Kaplan–Meier analysis,and the survival curves were compared using a log?rank test.Results:The 4?year overall survival,locoregional failure?free survival,distant failure?free survival,and failure?free sur?vival rates were not significantly different between the two groups(all P>0.05).However,patients in the CCRT group exhibited more severe acute adverse events than did patients in the NACT+RT group during radiotherapy,includ?ing leukopenia(30.2%vs.15.3%,P=0.016),neutropenia(25.9%vs.11.2%,P=0.011),and mucositis(57.8%vs.40.8%,P=0.028).After radiotherapy,patients in the CCRT group exhibited significantly higher rates of xerostomia(21.6%vs.Conclusions:The treatment outcomes of the NACT+RT and CCRT groups were similar;however,CCRT led to higher rates of acute and late toxicities.NACT+RT may therefore be a better treatment strategy for ascending?type NPC.

A model to predict the risk of lethal nasopharyngeal necrosis after re-irradiation with intensity-modulated radiotherapy in nasopharyngeal carcinoma patients

Background:For patients with nasopharyngeal carcinoma(NPC) who undergo re-irradiation with intensity-modulated radiotherapy(IMRT),lethal nasopharyngeal necrosis(LNN) is a severe late adverse event.The purpose of this study was to identify risk factors for LNN and develop a model to predict LNN after radical re-irradiation with IMRT in patients with recurrent NPC.Methods:Patients who underwent radical re-irradiation with IMRT for locally recurrent NPC between March 2001 and December 2011 and who had no evidence of distant metastasis were included in this study.Clinical characteristics,including recurrent carcinoma conditions and dosimetric features,were evaluated as candidate risk factors for LNN.Logistic regression analysis was used to identify independent risk factors and construct the predictive scoring model.Results:Among 228 patients enrolled in this study,204 were at risk of developing LNN based on risk analysis.Of the 204 patients treated,31(15.2%) developed LNN.Logistic regression analysis showed that female sex(P = 0.008),necrosis before re-irradiation(P = 0.008),accumulated total prescription dose to the gross tumor volume(GTV) ≥ 145.5 Gy(P = 0.043),and recurrent tumor volume >25.38 cm3(P = 0.009) were independent risk factors for LNN.A model to predict LNN was then constructed that included these four independent risk factors.Conclusions:A model that includes sex,necrosis before re-irradiation,accumulated total prescription dose to GTV,and recurrent tumor volume can effectively predict the risk of developing LNN in NPC patients who undergo radical re-irradiation with IMRT.

Clinical treatment considerationsin the intensity-modulated radiotherapy era for patients with NO-category nasopharyngeal carcinoma and enlarged neck lymph nodes

Background:Nasopharyngeal carcinoma(NPC) shows a high proportion of lymph node metastasis,and treatment guidelines have been developed for positive nodes.However,no irradiation guidelines have been proposed for patients with enlarged neck lymph nodes(ENLNs) that do not meet the radiological criteria of 10 mm in diameter for positive lymph nodes.This study aimed to determine the prognostic value and radiation dose for ENLNs in NO-category NPC patients treated with intensity-modulated radiotherapy(IMRT).Methods:We reviewed the medical data of 251 patients with non-metastatic,NO-category NPC treated with IMRT.Receiver operating characteristic curves were used to calculate the cut-off value of the ENLN diameter for the prediction of disease failure.The biological equivalent dose(BED) for ENLNs was calculated.Patient survival was compared between the small and large ENLN groups.Independent prognostic factors were identified using the Cox proportional hazards model.Results:The estimated 4-year regional relapse-free survival rate was higher in patients with ENLNs ≥5.5 mm than in those with ENLNs <5.5 mm(100%vs.98.8%,P=0.049),whereas disease-free,overall,and distant metastasis-free survival rates were similar between the two groups.After adjusting for various factors,ENLN diameter was not identified as an independent prognostic factor(P > 0.05 for all survival rates).In the subgroup analysis,patients receiving BED ≥72 Gy had a similar prognosis as patients receiving BED <72 Gy in both the small and large ENLN groups.The multivariate analysis also confirmed that BED≥72 Gy was not associated with significantly improved prognosis in patients with NO-category NPC.Conclusions:A BED of 72 Gy to ENLNs is considerably sufficient to provide a clinical benefit to patients with NO-category NPC.Prospective studies are warranted to validate the findings in the present study.

A Prospective Study on Therapeutic Gain by Concurrent Chemoradiotherapy for Stage Ⅱ-Ⅳa Nasopharyngeal Carcinoma

The benefit achieved by concurrent chemoradiotherapy（CCR） and sequential chemoradiotherapy（SCR） vs radiotherapy（RT） alone for patients with stage Ⅱ-Ⅳa nasopharyngeal carcinoma（NPC） was compared.A total of 113 patients with stage Ⅱ-Ⅳa NPC were allotted into CCR group（n=38）,SCR group（n=36） and RT alone group（n=39）.All patients were irradiated with the same RT technique to ≥66 Gy at 2 Gy per fraction,conventional 5 fractions/week in all groups.The CCR group received concurrent chemotherapy of weekly cisplatin for 7 weeks,and the SCR group received neoadjuvant and（or） adjuvant chemotherapy.The results showed that the 3-and 5-year overall survival rate was significantly higher in CCR group than in RT alone group（92.16% vs 61.54%,81.58% vs 51.28%,P〈0.005）.The median survival time was significantly longer in CCR group than in RT alone group（67.8 months vs 52.7 months,P〈0.005）.It was concluded that CCR could significantly improve overall survival rate,progression-free survival rate,and median survival time when compared with RT alone.

Forty-six cases of nasopharyngeal carcinoma treated with 50 Gy radiotherapy plus hematoporphyrin derivative:20 years of follow-up and outcomes from the Sun Yat-sen University Cancer Center

Background:With the improved overall survival(OS) of nasopharyngeal carcinoma(NPC) patients,the importance of quality of life(Qo L) is increasingly being recognized.For some radiosensitive NPC patients,whether low?dose radio?therapy can improve the Qo L without affecting clinical efficacy is unknown.This study aimed to assess the survival rates and Qo L of NPC patients treated with 50 Gy radiotherapy plus hematoporphyrin derivative(HPD).Methods:Forty?six newly diagnosed NPC patients treated with 50 Gy radiotherapy plus HPD between June 1988 and July 1992 were analyzed.All patients were restaged according to the 7th edition of the American Joint Commit?tee on Cancer staging system.The radiotherapy plan was designed on the basis of pretreatment computed tomog?raphy.The OS,local recurrence?free survival(LRFS),distant metastasis?free survival(DMFS),and disease?free survival(DFS) rates were estimated using the Kaplan–Meier method.Qo L was assessed using the Late Radiation Morbidity Scoring Criteria of the Radiation Therapy Oncology Group.Results:The 5?year OS,LRFS,DMFS,and DFS rates were 74.3%,72.6%,82.1%,and 61.2%,respectively.The corre?sponding 10?year rates were 38.4%,62.9%,78.5%,and 49.8%,respectively,and the 20?year rates were 27.7%,51.4%,78.5%,and 40.7%,respectively.None of the patients developed severe radiation?related complications,such as radiation?induced temporal lobe necrosis,hearing loss,trismus,and dysphagia.Conclusion:Some NPC patients were sensitive to 50 Gy radiotherapy plus HPD,and this sensitivity was characterized by long?term survival without significant late treatment morbidities.

Randomized study of sinusoidal chronomodulated versus flat intermittent induction chemotherapy with cisplatin and 5-fluorouracil followed by traditional radiotherapy for locoregionally advanced nasopharyngeal carcinoma

Neoadjuvant chemotherapy plus radiotherapy is the most common treatment regimen for advanced nasopharyngeal carcinoma(NPC).Whether chronomodulated infusion of chemotherapy can reduce its toxicity is unclear.This study aimed to evaluate the toxic and therapeutic effects of sinusoidal chronomodulated infusion versus flat intermittent infusion of cisplatin(DDP)and 5-fluorouracil(5-FU)followed by radiotherapy in patients with locoregionally advanced NPC.Patients with biopsy-diagnosed untreated stages III and IV NPC(according to the 2002 UICC staging system)were randomized to undergo2 cycles of sinusoidal chronomodulated infusion(Arm A)or flat intermittent constant rate infusion(Arm B)of DDP and 5-FU followed by radical radiotherapy.Using a"MELODIE"multi-channel programmed pump,the patients were given 12-hour continuous infusions of DDP(20 mg/m2)and 5-FU(750 mg/m2)for 5days,repeated every 3 weeks for 2 cycles.DDP was administered from 10:00 am to 10:00 pm,and 5-FU was administered from 10:00 pm to 10:00 am each day.Chronomodulated infusion was performed in Arm A,with the peak deliveries of 5-FU at 4:00 am and DDP at 4:00 pm.The patients in Arm B underwent a constant rate of infusion.Radiotherapy was initiated in the fifth week,and both arms were treated with the same radiotherapy techniques and dose fractions.Between June 2004 and June 2006,125 patients were registered,and 124 were eligible for analysis of response and toxicity.The major toxicity observed during neoadjuvant chemotherapy was neutropenia.The incidence of acute toxicity was similar in both arms.During radiotherapy,the incidence of stomatitis was significantly lower in Arm A than in Arm B(38.1%vs.59.0%,P=0.020).No significant differences were observed for other toxicities.The 1-,3-,and 5-year overall survival rates were 88.9%,82.4%,and 74.8%for Arm A and 91.8%,90.2%,and 82.1%for Arm B.The 1-,3-,and 5-year progression-free survival rates were 91.7%,88.1%,and 85.2%for Arm A and 100%,94.5%,and 86.9%for Arm B.The 1-,3-,and 5-year distant metastasis-free survival rates were 82.5%,79.1%,and 79.1%for Arm A and 90.2%,85.2%,and 81.7%for Arm B.Chronochemotherapy significantly reduced stomatitis but was not superior to standard chemotherapy in terms of hematologic toxicities and therapeutic response.

Neoadjuvant chemotherapy plus intensity-modulated radiotherapy versus concurrent chemoradiotherapy plus adjuvant chemotherapy for the treatment of locoregionally advanced nasopharyngeal carcinoma:a retrospective controlled study

Background:In the era of intensity-modulated radiotherapy(IMRT),the role of neoadjuvant chemotherapy(NAC)for locoregionally advanced nasopharyngeal carcinoma(NPC)is under-evaluated.The aim of this study was to compare the efficacy of NAC plus IMRT and concurrent chemoradiotherapy(CCRT)plus adjuvant chemotherapy(AC)on locoregionally advanced NPC.Methods:Between January 2004 and December 2008,240 cases of locoregionally advanced NPC confirmed by pathologic assessment in Sun Yat-sen University Cancer Center were reviewed.Of the 240 patients,117 received NAC followed by IMRT,and 123 were treated with CCRT plus AC.The NAC+IMRT group received a regimen that included cisplatin and 5-fluorouracil(5-FU).The CCRT+AC group received cisplatin concurrently with radiotherapy,and subsequently received adjuvant cisplatin and 5-FU.The survival rates were assessed by Kaplan-Meier analysis,and the survival curves were compared using a log-rank test.Multivariate analysis was conducted using the Cox proportional hazard regression model.Results:The 5-year overall survival(OS),locoregional relapse-free survival(LRRFS),distant metastasis-free survival(DMFS),and disease-free survival(DFS)were 78.0,87.9,79.0,and 69.8%,respectively,for the NAC+IMRT group and78.7,84.8,76.2,and 65.6%,respectively,for the CCRT+AC group.There were no significant differences in survival between the two groups.In multivariate analysis,age(<50 years vs.>50 years)and overall stage(Ⅲvs.Ⅳ)were found to be independent predictors for OS and DFS;furthermore,the overall stage was a significant prognostic factor for DMFS.Compared with the CCRT+AC protocol,the NAC+IMRT protocol significantly reduced the occurrence rates of grade 3-4 nausea-vomiting(6.5 vs.1.5%,P=0.023)and leukopenia(9.7 vs.0.8%,P=0.006).Conclusions:The treatment outcomes of the NAC+IMRT and CCRT+AC groups were similar.Distant metastasis remained the predominant mode of treatment failure.

Prognostic scoring system for locoregional control among the patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy

The prognostic value of T category for locoregional control in patients with nasopharyngeal carcinoma(NPC)has decreased with the extensive use of intensity-modulated radiotherapy(IMRT).We aimed to develop a prognostic scoring system(PSS)that incorporated tumor extension and clinical characteristics for locoregional control in NPC patients treated with IMRT.The magnetic resonance imaging scans and medical records of 717 patients with nonmetastatic NPC treated with IMRT at Sun Yat-sen University Cancer Center between January 2003 and January 2008 were reviewed.Age,pathologic classification,primary tumor extension,primary gross tumor volume(GTV-p),T and N categories,and baseline lactate dehydrogenase(LDH)level were analyzed.Hierarchical cluster analysis as well as univariate and multivariate analyses were used to develop the PSS.Independent prognostic factors for locoregional relapse included N2–3 stage,GTV-p≥26.8 mL,and involvement of one or more structures within cluster3.We calculated a risk score derived from the regression coefficient of each factor and classified patients into four groups:low risk(score 0),intermediate risk(score>0 and≤1),high risk(score>1 and≤2),and extremely high risk(score>2).The 5-year locoregional control rates for these groups were 97.4%,93.6%,85.2%,and 78.6%,respectively(P<0.001).We have developed a PSS that can help identify NPC patients who are at high risk for locoregional relapse and can guide individualized treatments for NPC patients.

Clinical role of ^(18)F-FDG PET/CT-based simultaneous modulated accelerated radiotherapy treatment planning for locally advanced nasopharyngeal carcinoma

Objective The aim of this study was to compare the long-term local control, overall survival, and late toxicities of positron emission tomography/computed tomography （PET/CT）-guided dose escalation radio- therapy versus conventional radiotherapy in the concurrent chemoradiotherapy treatment of locally ad- vanced nasopharyngeal carcinoma （NPC）. Methods Atotal of 48 patients with stage IIl-IVa NPC were recruited and randomly administered PET/CT- guided dose escalation chemoradiotherapy （group A） or conventional chemoradiotherapy （group B）. The dose-escalation radiotherapy was performed using the simultaneous modulated accelerated radiotherapy technique at prescribed doses of 77 gray （Gy） in 32 fractions （f） to the gross target volume （GTV）： planning target volume （PTV） 1 received 64 Gy/32 f, while PTV2 received 54.4 Gy/32 f. Patients in group B received uniform-dose intensity-modulated radiotherapy, PTV1 received 70 Gy/35 f and PTV2 received 58 Gy/29 f. Concurrent chemotherapy consisted of cisplatin [20 mg/m2 intravenous （IV） on days 1-4] and docetaxel （75 mg/m2 IV on days 1 and 8） administered during treatment weeks 1 and 4. All patients received 2-4 cycles of adjuvant chemotherapy of the same dose and drug regimen. Results The use of fluorine-18-fluorodeoxyglucose （18F-FDG） PET/CT significantly reduced the treat- ment volume delineation of the GTV in 83.3% （20/24） of patients. The 5-year local recurrence-free survival rates of the two groups were 100% and 79.2%, respectively （P = 0.019）. The 5-year disease free survival （DFS） rates were 95.8% and 75.0%, respectively （P = 0.018）. The 5-year local progression-free survival and DFS rates were significantly different. The 5-year overall survival （OS） rates were 95.8% and 79.2%, re- spectively. Differences in OS improvement were insignificant （P = 0.079）. Late toxicities were similar in the two groups. The most common late toxicities of the two arms were grade 1-2 skin dystrophy, xerostomia, subcutaneous fibrosis, and hearing loss. There were no cases of grade 4 late toxicity. Conclusion The use of 18F-FDG PET/CT-guided dose escalation radiotherapy is well tolerated and can reduce local recurrence rates for patients with locally advanced NPC compared to conventional chemora- diotherapy.

Stereotactic radiotherapy for the treatment of nasopharyngeal carcinoma: a Meta-analysis of 1371 cases in China

Objective The aim of this study was to clarify the outcomes of stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma and to promote scientific clinical treatment and research on it in China and other countries by creating a large data resource.Methods This Meta-analysis conducted a literature search using the China National Knowledge Infrastructure database for all clinical research articles on stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma in China.Data on patient cohort numbers and other research factors were recorded for every relevant clinical research article.Calculated and analyzed these fact sheets to pave the way for the objective of this project.Results A total of 40 clinical research articles including 1,371 patients in China from 1998 to 2012 were identified.The average cohort size was 34 patients(range 9-98 patients).The average total radiation dose range was 16-33.6 Gy.The average study or treatment duration was 3.51 years.The calculated average follow-up time was 31.59 months.Conclusion The study provided the largest resource for further research and Meta-analyses to determine the clinical pathway of stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma.The results indicated that variability in the total radiation dose,treatment or research time,and follow-up duration may have contributed to the complications and side effects of stereotactic radiotherapy for local residual and(or) local recurrent nasopharyngeal carcinoma in China.The calculated average total radiation dose,follow-up time,and treatment and research durations may be referenced for future treatment and research.This study also proposed worldwide cooperation for the metaanalysis of research articles on stereotactic radiotherapy for treating local residual and(or) local recurrent nasopharyngeal carcinoma.

Clinical Study on Simultaneous Modulated Accelerated Radiotherapy and Concurrent Chemotherapy for Locally Advanced Nasopharyngeal Carcinoma

OBJECTIVE To evaluate the clinical efficacy and toxicities of simultaneous modulated accelerated radiotherapy （SMART） and concurrent chemotherapy for locally advanced nasopharyngeal carcinoma. METHODS Eightyseven patients with nasopharyngeal carcinoma received SMART from April 2002 to September 2006. According to the UICC staging system, 30 patients were diagnosed as stage IIb, 42 patients stage III, 13 patients stage IVa and 2 patients stage IVb. The intensitymodulated radiotherapy was delivered with the ＂step and shoot＂ SMART technique with the prescribed dose of 66-76 Gy （2.2-2.4 Gy/day） to the gross tumor volume （GTV） and positive neck lymph nodes （GTVLN）, with 60 Gy （2.0 Gy/day） to the highrisk clinical target volume （CTV1）, encompassing the area around the nasopharynx and the upper neck, and with 54 Gy （1.8 Gy/day） to the lowrisk clinical target volume （CTV2）, including the lower neck and supraclavicular area. Among all the patients, 31 received 2 cycles of SMART concurrently with 5 fluorouracil （5-Fu） and cisplatin （the FP group） and 56 received 2 cycles of concurrent cisplatin. All the patients received 3 to 4 cycles of adjuvant combination chemotherapy of cisplatin and 5fluorouracil starting from the 1st month after completion of SMART. RESULTS With a median follow up of 59 months （ranging from 19 to 85 months）, the 1, 2 and 3year overall survival rates were 100%, 94.6% and 91.3% respectively. Acute mucositis and pharyngitis were more frequently observed in the FP group than in the cisplatin group. CONCLUSION SMART technique provides an excellent opportunity to spare normal tissue and is probably more biologically effective. Combination of single cisplatin was more tolerable.

Application of Support Vector Machine to Predict 5-year Survival Status of Patients with Nasopharyngeal Carcinoma after Treatment

Objective： Support Vector Machine （SVM） is a machine-learning method, based on the principle of structural risk minimization, which performs well when applied to data outside the training set. In this paper, SVM was applied to predict 5-year survival status of patients with nasopharyngeal carcinoma （NPC） after treatment, we expect to find a new way for prognosis studies in cancer so as to assist right clinical decision for individual patient. Methods： Two modelling methods were used in the study; SVM network and a standard parametric logistic regression were used to model 5-year survival status. And the two methods were compared on a prospective set of patients not used in model construction via receiver operating characteristic （ROC） curve analysis. Results： The SVM1, trained with the 25 original input variables without screening, yielded a ROC area of 0.868, at sensitivity to mortality of 79.2% and the specificity of 94.5%. Similarly, the SVM2, trained with 9 input variables which were obtained by optimal input variable selection from the 25 original variables by logistic regression screening, yielded a ROC area of 0.874, at a sensitivity to mortality of 79.2% and the specificity of 95.6%, while the logistic regression yielded a ROC area of 0.751 at a sensitivity to mortality of 66.7% and gave a specificity of 83.5%. Conclusion： SVM found a strong pattern in the database predictive of 5-year survival status. The logistic regression produces somewhat similar, but better, results. These results show that the SVM models have the potential to predict individual patient＇s 5-year survival status after treatment, and to assist the clinicians for making a good clinical decision.

Clinical Effect of Biafine in Preventing and Treating Radioactive Skin Destruction of Nasopharyngeal Carcinoma Patients Caused by Concurrent Intensity- Modulated Radiotherapy and Chemotherapy

OBJECTIVE To observe the clinical effect of Biafine cream in preventing and treating radioactive skin destruction of nasopharyngeal carcinoma （NPC） patients induced by synchronized intensity-modulated radiotherapy and chemotherapy. METHODS The patients were treated with Varian-600CD 6 MV X-ray three-dimensional （3D） conformal intensity-modulation radiotherapy （IMRT）, with a 120-blade multiple leaf-blade grating and in combination with synchronal Capecitabine chemotherapy. Fifty-one patients undergoing radiotherapy and chemotherapy were randomized into 2 groups： 25 in the treatment group received a Biafine cream application following the first radiotherapy and / or chemotherapy, while the other 26, served as controls. They received no application of the cream, but only followed normal procedures for conventional radiotherapy and health education. RESULTS The rate of the skin-reaction was 100% in the patients of both groups. A mild radiation reaction （grade-Ⅰ and Ⅱ） occurred as follows： 88.0% （22/25 cases） in the treatment group and 57.7% （15/26 cases） in the control group. A grade-Ⅲ radiation reaction developed in 12.0% （3/25 cases） in the treatment group, and 42.3% （11/26 cases） in the controls. There was a significant difference, P〈0.01 between the two groups. Concerning the degree of the skin response before the patients received a dose of 40 Gy, the radiation reaction emerged in 32.0% （8/25） of the cases in the treatment group, and in 96.2% （25/26） of the cases of the control group. CONCLUSION Biafine cream can effectively reduce the acute irradiation or chemotherapy-induced dermal injury. It can alleviate the patients＇ suffering, improve their quality of life, and can ensure less injurious radiotherapy.

Significant value of 18F-FDG-PET/CT in diagnosing small cervical lymph node metastases in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT).The present study aimed to evaluate the diagnostic values of PET/CT in identifying metastasis in SCLNs in NPC patients.Methods: Magnetic resonance images(MRI) and PET/CT scans for 470 patients with newly diagnosed, non-distant metastatic NPC were analyzed. Metastatic rates of SCLNs were defined by the positive number of SCLNs on PET/CT scans and total number of SCLNs on MRI scans. Receiver operating characteristic curve was applied to compare PET/CT-determined stage with MRI-determined stage.Results: In total, 2082 SCLNs were identified, with 808(38.8%) ≥ 5 and < 6 mm in diameter(group A), 526(25.3%)≥ 6 and < 7 mm in diameter(group B),374(18.0%)≥ 7 and < 8 mm in diameter(group C), 237(11.4%) ≥8 and<9 mm in diameter(group D),and 137(6.5%) ≥ 9 and <10 mm in diameter(group E).The overall metastatic rates examined by using PET/CT for groups A, B,C,D, and E were 3.5%, 8.0%, 31.3%, 60.0%, and 83.9%, respectively(P< 0.001). In level IV/Vb, the metastatic rate for nodes ≥ 8 mm was 84.6%. PET/CT examination resulted in modification of N category and overall stage for 135(28.7%) and 46(9.8%) patients, respectively. The areas under curve of MRIdetermined and PET/CT-determined overall stage were 0.659 and 0.704 for predicting overall survival, 0.661 and 0.711 for predicting distant metastasis-free survival, and 0.636 and 0.663 for predicting disease-free survival.Conclusions: PET/CT was more effective than MRI in identifying metastatic SCLNs, and the radiologic diagnostic criteria for metastatic lymph nodes in level IV/Vb should be re-defined.

Biomarkers for enhancing the radiosensitivity of nasopharyngeal carcinoma

Nasopharyngeal carcinoma(NPC) is a common head and neck malignancy. The incidence of NPC is higher in Southern China and Southeast Asia compared with Western countries. Given its high radiosensitivity, the standard treatment for NPC is radiotherapy. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after treatment by radiation. Thus, special emphasis has been given to the discovery of effective radiosensitizers. This review aims to discuss the biomarkers, classified according to the main mechanisms of radiosensitization, which can enhance the sensitivity of NPC cells to ionizing radiation.

Dosimetry Comparison between Volumetric Modulated Arc Therapy with RapidArc and Fixed Field Dynamic IMRT for Local-Regionally Advanced Nasopharyngeal Carcinoma

Objective: A dosimetric study was performed to evaluate the performance of volumetric modulated arc radiotherapy with RapidArc on locally advanced nasopharyngeal carcinoma (NPC). Methods: The CT scan data sets of 20 patients of locally advanced NPC were selected randomly. The plans were managed using volumetric modulated arc with RapidArc and fixed nine-field coplanar dynamic intensity-modulated radiotherapy (IMRT) for these patients. The dosimetry of the planning target volumes (PTV), the organs at risk (OARs) and the healthy tissue were evaluated. The dose prescription was set to 70 Gy to the primary tumor and 60 Gy to the clinical target volumes (CTV) in 33 fractions. Each fraction applied daily, five fractions per week. The monitor unit (MU) values and the delivery time were scored to evaluate the expected treatment efficiency. Results: Both techniques had reached clinical treatment’s requirement. The mean dose (Dmean), maximum dose (Dmax) and minimum dose (Dmin) in RapidArc and fixed field IMRT for PTV were 68.4±0.6 Gy, 74.8±0.9 Gy and 56.8±1.1 Gy; and 67.6±0.6 Gy, 73.8±0.4 Gy and 57.5±0.6 Gy (P<0.05), respectively. Homogeneity index was 78.85±1.29 in RapidArc and 80.34±0.54 (P<0.05) in IMRT. The conformity index (CI: 95%) was 0.78±0.01 for both techniques (P>0.05). Compared to IMRT, RapidArc allowed a reduction of Dmean to the brain stem, mandible and optic nerves of 14.1% (P<0.05), 5.6% (P<0.05) and 12.2% (P<0.05), respectively. For the healthy tissue and the whole absorbed dose, Dmean of RapidArc was reduced by 3.6% (P<0.05), and 3.7% (P<0.05), respectively. The Dmean to the parotids, the spinal cord and the lens had no statistical difference among them. The mean MU values of RapidArc and IMRT were 550 and 1,379. The mean treatment time of RapidArc and IMRT was 165 s and 447 s. Compared to IMRT, the delivery time and the MU values of RapidArc were reduced by 63% and 60%, respectively. Conclusion: For locally advanced NPC, both RapidArc and IMRT reached the clinic requirement. The target volume coverage was similar for the different techniques. The RapidArc technique showed some improvements in OARs and other tissue sparing while using reduced MUs and delivery time.