Xue Ming Sun

Analysis of dosimetric factors associated with temporal lobe necrosis (TLN) in patients with nasopharyngeal carcinoma (NPC) after intensity modulated radiotherapy

BackgroundThe radiation tolerance dose-volume in brain remains unclear for nasopharyngeal carcinoma (NPC) patients treated with intensity modulated radiotherapy (IMRT). We performed this study to investigate dosimetric factors associated with temporal lobe necrosis (TLN) in NPC patients treated with IMRT.MethodsFrom 2001 to 2008, 870 NPC patients were treated with IMRT. For the whole group, 40 patients have developed MRI-diagnosed TLN, and 219 patients were followed-up more than 60 months. Predictive dosimetric factors for TLN were identified by using univariate and multivariate analysis in these 259 patients.ResultsBy univariate analyses, rVX ( percent of temporal lobes receiving ≥ X Gy) and aVX ( absolute volumes of temporal lobes receiving ≥ X Gy, values of X considered were 10, 20, 30, 40, 50, 60, 66 and 70) were all significantly associated with TLN. Multivariate analysis by logistic regression showed that rV40 and aV40 were significant factors for TLN. All dosimetric factors in current serials were highly correlated one another (p < 0.001). The 5-year incidence of TLN for rV40 <10% or aV40 <5 cc is less than 5%. The incidence for rV40 ≥ 15% or aV40c ≥ 10c is increased significantly and more than 20%.ConclusionsIn this study, all dosimetric factors were highly correlated, rV40 and aV40 were independent predictive factors for TLN, IMRT with rV40 <10% or aV40 <5 cc in temporal lobe is relatively safe.

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.

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.

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

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).

Prognostic analysis of early-stage squamous cell carcinoma of the vulva

AimThe aim of this study was to analyze prognostic factors of early-stage squamous cell carcinoma of the vulva.MethodsA retrospective analysis was conducted on 35 patients who were treated for early-stage squamous cell carcinoma of the vulva at Sun Yat-sen University Cancer Center from January 1980 to December 2005. The Statistical Package for Social Science (SPSS) was used to compare the different strategies of operation and to analyze the prognostic factors.ResultsThirty-five patients had early-stage squamous cell carcinoma of the vulva. Of these cases, 26 were well differentiated, seven were moderately differentiated, and two were poorly differentiated. The five-year survival rate was 77.1%. Five cases were in FIGO stage 1a and 30 cases were in stage 1b; median survival times were 182.3 months and 152.5 months, and the five-year survival rates were 100% and 81.5% (P >0.05), respectively. The five-year survival of the patients who underwent local excision; radical vulvectomy and en bloc resection of inguinofemoral lymphadenectomy; orradical vulvectomyen bloc resection of inguinofemoral lymphadenectomy, and pelvic lymph nodes was 50%, 81.8%, and 83.9%, respectively. For these cases, 74.3% of the tumors were medial while 25.7% were lateral, and the five-year survival rates of patients according to tumor location were 87.0% and 64.8% (P <0.05), respectively. The inguinal lymph node not increased and active were 16 cases (45.7%), and increased, active and hard were 17 cases (48.6%), and syncretic were two cases (5.7%), five-year survival rates were 73.3%, 92.9% and 50% (P <0.05), respectively. Of these cases, 74.3% of the tumors were cauliflower-like and 25.7% were nodular; five-year survival rates by tumor type were 91.3% and 66.7% (P <0.05), respectively.ConclusionsFor patients with early-stage squamous cell carcinoma of the vulva, surgical operation is the primary, yet the best, treatment. The related prognostic factors were tumor location (lateral/medial), stage, gross morphology, and clinical state of the inguinal lymph node.