| Background and Objectives:Although treatment options for esophageal carcinoma have been improved during the past decades, the overall prognosis remains poor irrespective of the therapeutic modality applied. With respect to radiotherapy, the need for improved clinical outcome in esophageal carcinoma has led to further efforts in radiation delivery and performance. Three-dimensional (3D) conformal radiation therapy is one of the most commonly accepted radiotherapy techniques at presence, for its precise and reliable dose distribution in target and normal tissue. Given the proved efficacy of concurrent chemoradiotherapy using conventional radiation technique, the question arouse in how far the survival is improved in 3D-comformal radiation planning era. This research aims to evaluate the-treatment outcomes of 3D-conformal radiation therapy concomitant with chemotherapy versus 3D-conformal radiotherapy alone in patients with esophageal carcinoma, including local control, distant metastases, long-term survival and late complications.Methods:A retrospective analysis was conducted to the clinical data of 351 patients pathologically confirmed with esophageal carcinoma.93 cases received concurrent chemoradiotherapy, and 258 received radiotherapy alone.The gross tumor volume (GTV) consisted of the primary esophageal gross tumor shown on mediastinal window of chest computed tomography(CT). In addition, the regions of tumor described on esophagoscopy but not seen on CT were also included.Regional lymph nodes≥10 mm in maximal diameter were considered positive and included in the GTV. For the planning target volume (PTV), a 1.0-1.5cm margin was placed around GTV, and 3.0cm superior and inferior of GTV (at the long axis of esophagus) to encompass potential submucosal invasion. The beam's eye view (BEV) and multiplanar reconstruction facilities were used to fully encompass the PTV and to minimize dose to normal tissues. The dose was prescribed to the center of PTV with no correction of inhomogeneity. Most of the cases used a three-field approach with one anterior and a pair of posterior oblique portals for lesions in the thorax, and most of the cases used a anterior and two horizontal portals or two anterior oblique portals with wedges for lesions in the neck. Optimization of the plan was based on dose-volume histogram (DVH) analyses and constraints for normal structures. Radiotherapy was delivered using 6 MV photons with multileaf collimator (MLC) or cerrobend blocks. Radiation dose ranged from 40 to 76Gy (median 66Gy) with conventional fractionation. The patients who underwent chemoradiotherapy received two cycles of concurrent and two cycles of adjuvant combination of cisplatin (75mg/m2) and 5-fluorouracil(500mg/m2) by 4-day infusion. The radiotherapy alone group received the same radiation therapy schedule without chemotherapy.Statistic:Kaplan-Meier method was used to analyze the survival and log-rank test was used to evaluate the difference between the groups. Cox regression model was used to analyze the prognostic factor. The first day of irradiation was taken as the initial date to begin observation for all eventsResults:The median follow-up time was 18.5 months. The 1,2,3-year overall survival rates in patients with concurrent chemoradiotherapy and with radiotherapy alone were 77.7%, 55.4%,44.4%; and 68.4%,41.4%,32.7%, respectively (χ2=5.777, P=0.016). The 1,2,3-year disease-specific survival rates were 79.8%,58.1%,46.5% in chemoradiotherapy group while 70.6%,44.4% and 36.0% in radiation alone group, respectively(χ2= 4.445, P=0.035). The overall survival rates and disease-specific survival rates had been improved significantly in chemoradiotherapy group compared with radiotherapy alone group. Recurrence-free survival (RFS) rates were also in favour of concomitant chemoradiotherapy group(χ2=4.043, P=0.044). The incidence of late complications did not increase significantly in the patients who received concurrent chemotherapy. By univariate and multivariate analyses, female gender, primary tumor location and concurrent chemotherapy were independent factors predictive of better survival.Conclusion:3D-comformal radiation therapy is an accepted reference standard approach for non-operative esophageal cancer. The concomitant addition of cisplatin and 5-Fu has a statistically significant positive impact on overall and disease-specific survival rates. This combined treatment modality appears to offer therapeutic benefit without increasing late complications. |
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