Three-Dimensional Conformal and Intensity Modulated Dynamic Radiotherapy in Juvenile Nasopharyngeal Angiofibroma

Objective: Juvenile Nasopharyngeal Angiofibroma (JNA) is a benign neoplasm with a high vascularity component, greater craniofacial involvement in adolescent patients, and aggressive local behaviour. In unresectable patients, radiotherapy is a therapeutic option for local control. Our aim in this study was to analyze the clinical benefit and local control provided by two modalities of radiotherapy: the Three-Dimensional Conformal (3DC) technique and volumetric modulated arc therapy (VMAT), applied to pediatric patients with JNA considered unresectable and non-recurrent. Methods: In retrospective study, the information was recorded from pediatric patients with a diagnosis of non-recurrent and unresectable JNA treated with radiotherapy at the Oncology Hospital of the National Medical Center SXXI of Mexico City, from March 2010 to March 2021. Radiotherapy management and its association with clinical outcomes of tumour control, and symptoms were assessed. In addition, an evaluation of acute and chronic toxicity was performed. Results: It was found that the median age was 14 years. 9 patients (37.5%) underwent 3DC and 15 (62.5%) VMAT. In terms of local control, and progression-free survival, we did not find significant difference between radiotherapy modalities (p ≤ 0.57). Acute toxicity for both modalities presented statistical differences for radio epithelitis (p = 0.03). Only Grade I and II radiation-induced acute toxicity was observed. Regarding chronic toxicity, statistical significance was observed for craniofacial hypoplasia, in relation to its absence in the VMAT group (p = 0.001). Conclusion: The VMAT presents improvements in dosimetry parameters that improve patient toxicity. In both techniques adequate tumour control was observed, however, the rarity of the disease is a limitation to establish the most appropriate therapeutic technique.

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 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.

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 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.

Effects of dosimetric inadequacy on local control and toxicities in the patients with T4 nasopharyngeal carcinoma extending into the intracranial space and treated with intensity.modulated radiotherapy plus chemotherapy

Background:To protect neurological tissues,underdosing occurs in most cases of T4 nasopharyngeal carcinoma(NPC) with intracranial extension.In this study,we aimed to evaluate the effect of dosimetric inadequacy on local control and late neurological toxicities for patients treated with intensity-modulated radiotherapy(IMRT) plus chemotherapy.Methods:We prospectively enrolled patients who had non-metastaticT4 NPC with intracranial extension treated between January 2009 and November 2013.The prescribed dose was 66.0-70.4 Gy to the primary planning target volume(primary gross tumor volume [GTVp;i.e.,the nasopharyngeal tumor] +5.0 mm).Dose-volume histogram parameters were calculated,including minimum point dose(D_(min)) and dose to 95% of the target volume(D95).All patients received chemotherapy with the cisplatin,5-fluorouracil,and docetaxel regimen.Survivals were estimated using the Kaplan-Meier method and compared using the log-rank test.Results:In total,41 patients were enrolled.The local partial response rate was 87.8% after induction chemotherapy.With a median follow-up of 51 months,7 patients experienced failure in the nasopharynx;the 3-year local failure-free survival and overall survival rates of the 41 patients were 87.4% and 90.2%,respectively.The actual mean D_(min) to the GTVp was 55.2 Gy(range 48.3-67.3 Gy),and D95 was 61.6 Gy(range 52.6-69.0 Gy).All doses received by neurological organs remained well within their dose constraints.No patients developed temporal lobe necrosis or other neurological dysfunctions.Conclusions:With relative underdosed IMRT plus effective chemotherapy,the patients achieved satisfactory local control with few late toxicities of the central nervous system.Determining the acceptable extent of dosimetric inadequacy requires further exploration.

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.

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.

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.

Selective partial salivary glands sparing during intensity-modulated radiation therapy for nasopharyngeal carcinoma

Objective This study evaluated the dosimetric consequences of selective partial salivary gland sparing during intensity-modulated radiotherapy(IMRT) for patients with nasopharyngeal carcinoma(NPC).Methods Ten patients with NPC were enrolled in the study.Two IMRT plans were produced for each patient:conventional(control) and partial salivary glands-sparing(treatment),with dose constraints to the entire parotid glands or partial salivary glands(including the parotid and submandibular glands,delineated with the adjacent distance of at least 0.5 cm between the glands and PTV,the planning target volume) in planning,respectively.Dosimetric parameters were compared between the two plans,including the V_(110%),V_(100%),V_(95%)(the volume covered by more than 110%,100%,or 95% of the prescribed dose),Dmin(the minimum dose) of PTV,homogeneity index(HI),conformity index(CI),and the mean dose and percentage of the volume receiving 30 Gy or more(V_(30)) for the parotid glands and submandibular glands.Results Treatment plans had significantly lower mean doses and V_(30) to both the entire parotid glands and partial parotid glands than those in control plans.The mean doses to the partial submandibular glands were also significantly lower in treatment plans than in control plans.The PTV coverage was comparable between the two plans,as indicated by V_(100%),V_(95%),Dmin,CI,and HI.The doses to critical structures,including brainstem and spinal cord,were slightly but not significantly higher in treatment plans than in control plans.Conclusion A selective partial salivary gland-sparing approach reduces the doses to parotid and submandibular glands during IMRT,which may decrease the risk of post-radiation xerostomia while not compromising target dose coverage in patients with NPC.

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.

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.

尼妥珠单抗联合奈达铂化疗及调强适形放疗治疗局部晚期鼻咽癌的临床效果分析

目的:分析尼妥珠单抗联合奈达铂化疗及调强适形放疗(IMRT)治疗局部晚期鼻咽癌的临床效果。方法:选取2017年1月—2019年12月北海市人民医院收治的局部晚期鼻咽癌患者80例作为研究对象,随机分为对照组和试验组,各40例。对照组给予奈达铂化疗和IMRT,试验组在对照组基础上给予尼妥珠单抗治疗。比较两组治疗效果、远期生存率、肿瘤标志物水平、不良反应发生情况。结果:试验组治疗总有效率高于对照组,差异有统计学意义(P=0.025)。两组局部无复发生存率、远处无转移生存率、总生存率比较,差异无统计学意义(P>0.05);试验组无疾病生存率高于对照组,差异有统计学意义(P=0.013)。治疗前,两组糖抗原125(CA125)、细胞角蛋白19片段(CYFRA21-1)水平比较,差异无统计学意义(P>0.05);治疗后,两组CA125、CYFRA21-1水平均低于治疗前,且试验组低于对照组,差异有统计学意义(P<0.05)。两组不良反应总发生率比较,差异无统计学意义(P>0.05)。结论:尼妥珠单抗联合奈达铂化疗及IMRT治疗局部晚期鼻咽癌的临床效果显著,能够延长患者生存期,降低肿瘤标志物水平及不良反应发生率。

同步推量调强放疗在鼻咽癌中的应用效果及对免疫功能的影响

目的探讨同步推量调强放疗在鼻咽癌中的应用效果及对免疫功能的影响。方法选取2019年1月至2020年1月于江西省赣州市人民医院诊治治疗的94例鼻咽癌患者,使用随机数字表法将其分为观察组(同步推量调强放疗)和对照组(常规调强放疗),各47例。对比两组的近远期疗效、免疫功能指标、肿瘤细胞生长促进因子水平及毒副反应发生率。结果观察组的治疗总有效率高于对照组;2年无进展生存率及2年无远处转移生存率高于对照组,但差异相较无统计学意义(P>0.05)。治疗前,两组的CD3+、CD4+/CD8+、CD15+及CD56+水平相较差异不显著(P>0.05);治疗后,两组的各项指标水平均降低,但观察组高于对照组(P>0.05)。治疗前,两组的转化生长因子-β1(TGF-β1)和血管内皮生长因子(VEGF)水平相较差异不显著(P>0.05);治疗后,两组的两项指标水平均降低,观察组低于对照组(P<0.05)。观察组的毒副反应发生率低于对照组(P<0.05)。结论同步推量调强放疗治疗鼻咽癌,可提高近期疗效,减轻免疫功能损伤,降低肿瘤细胞生长促进因子水平,减少毒副反应,疗效显著,且安全性较高。

不同级别肿瘤中心医师对鼻咽癌调强放疗靶区和危及器官勾画差异比较

目的:评估不同级别肿瘤中心医师对鼻咽癌调强放疗计划靶区和危及器官勾画的个体化差异,为多中心放疗临床试验的质量控制提供数据参考。方法:随机抽取12例不同TMN分期的鼻咽癌患者,3名同一市级肿瘤中心医师以手工方式勾画每例患者的靶区(GTVnx)和危及器官(OAR)。以国家区域级肿瘤中心放疗专家手工修改和确认的靶区(GTVnx)和OAR勾画结构作为标准勾画。采用绝对体积差异比(△V_diff)、体积最大/最小比(MMR)、离散系数(CV)和体积相似性指数(DSC)分别比较不同级别肿瘤中心(市级与国家区域级)医师之间和市级肿瘤中心3名医师之间的器官勾画差异,并进一步比较不同级别肿瘤中心医师对不同TMN分期的鼻咽癌放疗计划器官的勾画差异。结果:不同级别肿瘤中心(市级与国家区域级)医师之间勾画GTVnx体积差异明显,3名医生中的最大△V_diff、MMR和CV分别为97.23%±83.45%、2.19±0.75和0.31±0.14,平均DSC<0.7。同时,他们之间对于左右视神经、视交叉、脑垂体等小体积OAR勾画差异也较大,平均MMR>2.8,CV>0.37,DSC<0.51;但对于脑干、脊髓、左右眼球、左右下颌骨等大体积OAR的勾画差异相对较小,平均的△V_diff<42%,MMR<1.55,DSC>0.7。相比于不同级别肿瘤中心医师之间的勾画差异,市级肿瘤中心3名医生勾画差异有一定的减小。另外,不同级别肿瘤中心医师之间对不同分期的鼻咽癌靶区勾画也存在差异,相对早期患者(I或II期)的靶区勾画,他们之间在对晚期患者(III或IV期)靶区勾画的差异更小,平均△V_diff和DSC值分别为(98.31%±67.36%vs 69.38%±72.61%, P<0.05)和(0.55±0.08 vs 0.72±0.12, P<0.05)。结论:不同级别肿瘤中心医师勾画鼻咽癌放疗计划靶区和OAR存在差异,尤其对早期患者靶区(GTVnx)和小体积OAR的勾画。为确保多中心临床试验的准确性,建议对不同级别医师进行统一培训并审核其勾画结果,以减少差异对治疗结果的影响。

鼻咽癌放疗头颈部摆位误差及外轮廓变化对放疗剂量的影响

目的:采用千伏级锥形束CT(CBCT)获取分次间鼻咽癌调强放疗中的外轮廓变化及摆位误差,分析其对靶区及危及器官剂量分布的影响。方法:选取21例鼻咽癌患者,将全部患者的137次CBCT图像与定位CT图像匹配后得到左右、头脚、腹背方向的摆位误差数据。选取颈部3个不同层面,测量其外轮廓横切面宽度,并利用Pearson系数和独立样本t检验分析其对摆位误差的影响。基于CBCT影像制定模拟计划,分析摆位误差和外轮廓变化对放疗剂量的影响,并应用Mann-Whitney秩和检验进行显著性分析。结果:左右、头脚、腹背方向的摆位误差分别为(1.04±0.73)、(1.13±0.87)、(1.38±0.95)mm。A、B、C层面上的头颈部最大外轮廓变化率分别为15.36%、14.94%、14.99%。模拟计划显示GTV D_(98)、CTV1 D_(95)、CTV2 D_(95)靶区的模拟计划的剂量均小于执行的计划剂量,差异有统计学意义(P<0.05);脑干和脊髓的模拟计划D_(max)均大于计划剂量,差异有统计学意义(P<0.05)。结论:通过模拟计划可知,当摆位误差和外轮廓变化等不确定性因素存在时,靶区的剂量变化较大,其中GTV D_(98)最大减小11.49%,CTV1 D_(95)、CTV2 D_(95)最大变化率分别为12.88%、21.64%。除左右晶体和左腮腺之外,其余的危及器官和靶区剂量均有显著性差异,表明实际放疗中摆位误差和外轮廓变化的存在会对剂量分布造成显著影响。

治疗前乳酸脱氢酶水平对局部复发鼻咽癌挽救性调强放疗的预后意义

目的探讨治疗前血清乳酸脱氢酶(lactate dehydrogenase,LDH)水平在挽救性调强放疗(IMRT)的局部复发性鼻咽癌(NPC)患者中的预后价值,并确定与rT分级的相关性。方法回顾性分析2018年1月~2022年4月在深圳市龙岗区耳鼻咽喉医院接受挽救性IMRT治疗的97例局部复发、非转移性NPC患者的病例资料,其中死亡51例、远处转移18例、局部失败30例和出现预后不良事件(死亡、肿瘤远处/局部转移)67例。获得所有患者临床资料、局部无失败生存(local failure-free survival,LFFS)、无远处转移生存(distantmetastasis-freesurvival,DMFS)和总生存时间(overallsurvival,OS),分析LDH与NPC患者挽救性IMRT预后的关系。结果死亡组[221.25(178.24,339.13)U/L vs.124.82(79.0,159.50)U/L,Z=-5.122]、局部失败组[230.75(170.89,394.50)U/Lvs.157.85(91.78,216.95)U/L,Z=-3.442]、远处转移组[261.62(153.55,465.50)U/L vs.168.98(101.75,237.75)U/L,Z=-2.478]和预后不良组[220.05(167.20,506.16)U/L vs.93.45(69.95,154.35)U/L,Z=-6.018]患者挽救性IMRT前血清LDH水平显著更高,P均<0.05。将血清LDH水平根据中位值划分为二分类变量(≥177.50 U/L vs.<177.50 U/L),Cox单因素模型发现LDH影响LFFS、DMFS、OS和毒性相关死亡(toxic-related death,TRD)的危险比分别为3.759(1.660~8.558)、4.217(1.383~12.861)、3.226(1.715~6.069)、3.363(1.750~6.463),P<0.05。多变量回归分析中,LDH仍然是LFFS、DMFS、OS、TRD的独立预后因素(P<0.05)。与LDH<177.50 U/L患者比较,LDH≥177.50 U/L组患者更多发生肿瘤局部进展相关死亡,且LDH≥177.50 U/L组患者无LFFS期、无DMFS期和OS期更短(Log-rank=11.624、7.559、14.758),P均<0.05。在预测总生存率方面,在r T分级中加入LDH优于单独的r T分级。结论LDH是预测局部复发、非转移性NPC患者在挽救IMRT后LFFS、DMFS、OS和TRD的一个重要因素,LDH与r T分级联合预测总生存率的价值较高。

鼻咽癌调强放疗期间重度口腔黏膜炎相关参数的预测因素分析

目的探讨接受调强放疗(IMRT)的鼻咽癌患者发生严重口腔黏膜炎(SOM)的影响因素,建立预测SOM的正常组织并发症概率(NTCP)模型并进行验证。方法对2021年6月至2022年3月接受评估和治疗的95例鼻咽癌患者的临床变量和辐射剂量学参数进行回顾性分析。使用基于最小绝对值收缩和选择算子(LASSO)回归模型建立NTCP模型,确定SOM的最佳预测因素。建立单变量截止剂量NTCP模型,以确定剂量-体积限制,并对NTCP模型的辨别能力进行评价。结果95例患者中有43例(45.3%)出现SOM。利用LASSO法筛选变量,IMRT后鼻咽癌患者V 35、T分期、年龄和诱导化疗周期数是影响SOM的独立预测因素(P<0.05)。NTCP模型为S=-16.220+(V_(35)×0.059)+(T分期×0.655)+(年龄×0.083)+(诱导化疗周期数×0.537)。基于V 35拟合体积-反应曲线,拟合参数包括T分期、年龄、诱导化疗周期数,当鼻咽癌患者口腔黏膜V 35约为44.5%时,SOM风险为50.0%。NTCP的受试者工作特征曲线下面积为0.89(95%CI:0.83~0.96)。结论本研究建立并验证了预测SOM的NTCP模型,尤其是V 35,可用于预测鼻咽癌患者放疗后SOM的发病风险。

容积旋转调强放疗治疗鼻咽癌的效果及急性口腔黏膜反应分析

目的分析容积旋转调强放疗(VMAT)治疗鼻咽癌的效果及对急性口腔黏膜反应的影响。方法采取前瞻性研究,选择2021年10月至2022年10月我院收治的80例鼻咽癌患者作为研究对象,按随机数字表法分为两组,各40例。对照组采取静态调强适形放疗(s-IMRT)治疗,观察组采取VMAT治疗。治疗后,比较两组患者临床疗效、治疗效率(加速器跳数、治疗时间)、计划靶区剂量参数[肿瘤靶区(PGTV)、计划靶区(PTV):均匀性指数(HI)、适形性指数(CI)、最小剂量(D_(min))、最大剂量(D_(max))、平均剂量(D_(mean))]、危及器官剂量参数(腮腺D_(mean)、颞颌关节V_(40))、皮肤、口腔黏膜反应分级;采用双变量相关tau-b(K)分析,急性口腔黏膜反应分级与腮腺D_(mean)、颞颌关节V_(40)剂量的关系。结果治疗后,观察组总有效率(92.50%)高于对照组(75.00%)(P<0.05);观察组加速器跳数、治疗时间[(658.04±103.36)MU、(3.14±0.46)min]低于对照组[(1844.25±462.47)MU、(7.84±1.09)min](P<0.05);观察组PGTV的CI(0.45±0.09)高于对照组(0.37±0.08),PTV的CI(0.40±0.16)高于对照组(0.29±0.08),D_(mean)[(64.38±4.43)Gy]低于对照组[(66.49±5.87)Gy](P<0.05);观察组腮腺D_(mean)、颞颌关节V_(40)[(34.14±5.29)Gy、(4.29±0.67)Gy]低于对照组[(37.05±6.33)Gy、(5.11±1.32)Gy](P<0.05);观察组急性口腔黏膜反应发生率(37.50%)低于对照组(72.50%)(P<0.05);采用双变量相关tau-b(K)分析,急性口腔黏膜反应分级与腮腺D_(mean)、颞颌关节V_(40)剂量呈正相关(r>0,P<0.05)。结论VMAT治疗鼻咽癌能够有效调节靶区剂量,控制危及器官剂量,降低急性口腔黏膜反应发生率,提升治疗效率。

适形调强放疗同步靶向治疗对鼻咽癌患者肿瘤标志物的影响研究

目的:探讨适形调强放疗同步靶向治疗在鼻咽癌患者中的效果及对肿瘤标志物的影响。方法:选择2020年3月—2023年3月阳江市人民医院肿瘤一科收治的鼻咽癌患者60例为对象,以信封法分为两组,各30例。对照组采用适形调强放疗,观察组在对照组基础上联合靶向治疗。比较两组客观缓解率(ORR)、肿瘤标志物、血管内皮生长因子(VEGF)、血小板反应蛋白-1(TSP-1)、转化生长因子β_(1)(TGF-β_(1))、白细胞介素-6(IL-6)、血管内皮生长因子受体2(VEGFR-2)水平及毒副反应发生率。结果:观察组ORR为83.33%,高于对照组的50.00%,差异有统计学意义(P<0.05);两组治疗后肿瘤标志物均降低,观察组癌胚抗原(CEA)、鳞状细胞癌抗原(SCCA)及细胞角蛋白19片段(Cyfra21-1)水平均低于对照组,差异均有统计学意义(P<0.05);两组治疗后生化指标均改善,观察组VEGF、VEGFR-2、TGF-β_(1)及IL-6均低于对照组,TSP-1高于对照组,差异均有统计学意义(P<0.05);两组毒副反应发生率比较,差异无统计学意义(P>0.05)。结论:适形调强放疗同步靶向治疗用于鼻咽癌患者中,能提高ORR,降低肿瘤标志物、VEGF、TGF-β_(1)、IL-6及VEGFR-2水平,不增加毒副反应发生率。