A Study Of Conformal Radiotherapy Combined With Chemotherapy For Esophageal Cancer

Objective: To observe the effect and side effects of the three dimensional conformal radiotherapy(3D-CRT)concuren- -tly combined with PLF region chemotherapy for mediate and advanced stage esophageal cancer, and analyze treatment plan and correlative factors of patients.Methods: 62 patients of untreated esophageal carcinoma were treated by the three dimensional conformal radiotherapy (3D-CRT) concurrently combined with PLF region chem- -otherapy in the Fourth Hospital of Hebei Medical University form September 2006 to October 2008. After scanning by CT simulator , the CT images were transferred through local network to the treatment planning system (Pinnacle 7.6c or Pinnacle 8.0c) and reconstructed by TPS. The gross tumor volume (GTV),clinical target volume (CTV), planning target volume (PTV) and organs at risk (OAR) were contoured with the findings of esophagogram, esophagoscopy and CT images. Physicists made the three dimensional conformal radiotherapy plan for each patient, the most excellent dose distribution for GTV, CTV, PTV and normal tissues around was achieved by TPS. The prescription dose was 6000 cGy with conventional fractionation: 180~200cGy per fraction, one fraction per day, 5 fractions per week, total 30～34 fractions. The PLF region chemotherapy (DDP 12 mg/m~2.d, CF 200 mg/d, 5-Fu 500 mg/m~2.d, d1～5) was administered from the beginning of 3D-CRT at 28-day intervals and total 2 cycles at least for every patient.Results: (1)The average length of lesion was 4.97 cm shown on esophageal barium meal, 4.67 cm on esophagoscopy and 7.24 cm on CT scan. The average greatest diameter of lesion was 4.11 cm (right-left) shown on CT scan. The average volume of GTV was 46.31㎝3, The median volume of GTV was 35.95㎝3.(2)In three dimensional conformal radiotherapy , the mean dose of GTV was 6413.61 cGy; the doses of 100% GTV volume and of 95% GTV volume were 6043.36 cGy and 6254.15 cGy respectively; the doses of 100% CTV volume and of 95% CTV volume were 5506.64 cGy and 6129.48 cGy respectively;the doses of 100% PTV volume and of 95% PTV volume were 4703.55 cGy and 5900.37 cGy respectively. In intensity modulated radiation therapy, the mean dose of GTV was 6832.10 cGy; the doses of 100% GTV volume and of 95% GTV volume were 6494.40 cGy and 6705.17 cGy respectively; the doses of 100% CTV volume and of 95% CTV volume were 6117.80 cGy and 6466.40 cGy respectively;the doses of 100% PTV volume and of 95% PTV volume were 4869.27 cGy and 6076.53 cGy respectively. The V20 of lungs was 22.86%. The average maximal dose of spinal cord was 4221.84 cGy. (3) All patients completed the radiotherapy on schedule. 15 patients completed 1 cycle chemotherapy;18 patients completed 2 cycles chemotherapy;29 patients completed 3 cycles or more chemotherapy.(4)The overall response rate was 96.77% (CR+PR). The complete response rate was 66.13% (41/62) and the partial response rate was 30.65% (19/62). Of these 62 patients,80.65% (50/62) patients developed acute radiation esophagitis:12 patients with grade 0, 18 patients with grade 1, 26 patients with grade 2 and 6 patients with grade 3. 38.71% (24/62) patients developed acute radiation pneumonitis: 38 patients with grade 0, 13 patients with grade 1, 7 patients with grade 2 and 4 patients with grade 3. While 80.65% (50/62) patients also developed hypoleukemia: 12 patients with grade 0, 20 patients with grade 1, 24 patients with grade 2 and 6 patients with grade 3. (5) The final follow-up date was on October 31, 2008,2 patients disappeared and the follow-up rate was 96.77%. Among 11 dead patients, 5 cases died of distant metastasis, 5 cases died of local failure or recurrence and 1 case died of heart disease. By Kaplan-Meier survival analysis, the overall 1-year and 2-year survival rates were 86.08% and 41.75% respectively. The overall 1-year and 2-year local control rates were 86.58% and 60.47% respectively. The median survival time was 22 months. The 1-year survival rates were 88.89% and 85.81% for patients of 3D-CRT and IMRT respectively. The 1-year survival rates were 87.50% and 77.90% for cervical or upper-thoracic segment of esophageal carcinoma and middle or lower-thoracic segment of esophageal carcinoma respectively. The 1-year survival rates were 86.05% and 85.91% for patients of tumor <7.20 cm and≥7.20 cm. The 1-year survival rates were 88.50% and 82.11% for patients of GTV volume<46.31 cm~3 and≥46.31 cm~3 . For GTV volume<35.95 cm~3 and≥35.95 cm~3 group , the 1-year survival rates were 90.63% and 81.60% respectively. The 1-year survival rates were 90.20% and 82.95% for patients with trachea invasion and without trachea invasion respectively. The 1-year survival rates were 83.32% and 92.86% for patients with lymph node metastasis and without lymph node metastasis respectively. The 1-year survival rates were 91.72% and 62.25% for patients of over 2 cycles chemotherapy and lower 2 cycles chemotherapy respectively. The 1-year survival rates were 92.86% and 75.63% for patients of over 3 cycles chemotherapy and lower 3 cycles chemotherapy respectively. The 1-year survival rates were 90.48% and 72.73% for patients of 0-1 grade and 2-3 grade acute radiation pneumonitis respectively. All the differences were not significant (P>0.05). The 1-year survival rates were 77.89% and 96.30% for patients with aortic invasion and without aortic invasion respectively, there was significant difference(P=0.0436).Conclusions:(1) The method of the three dimensional conformal radiotherapy combined with chemotherapy is feasible to treat mediate and advanced stage esophageal cancer , but the local control rate and the survival rate weren't superior to single 3DCRT,the distant metastasis rate wasn't inferior to single 3DCRT. (2) There were not obvious correlation between tumor station, tumor length, tumor volume, trachea invasion or without trachea invasion , lymph node metastasis or without lymph node metastasis with the survival rate. (3) There was significant difference between aortic invasion or without aortic invasion with the survival rate, this indicated tumor T stage was important prognostic indicator for esophageal cancer.(4) The intensified chemotherapy didn't improve the survival rate. (5) The intensity modulated radiation therapy wasn't superior to the three dimensional conformal radiotherapy in improving the survival rate and the local control rate .(6) The method of the three dimensional conformal radiotherapy concurrently combined with chemotherapy increased acute radiation esophagitis, but didn't increase acute radiation pneumonitis.