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The delineation of clinical target volume(CTV)is a critical step in planning three-dimensional conformal radiation therapy(3D-CRT)or intensity-modulated radiation therapy(IMRT)for gastric cancer.Recommendations for target volume construction have been published for two-dimensional(2D)techniques,but are scarce for 3D CT-based CTV contouring.Recent advances and controversies in delineation of postoperative radiotherapy CTV for gastric cancer have been introduced.Further optimization of target volume for postoperative 3D-CRT/IMRT in gastric cancer is necessary.
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Objective The aim of this study was to investigate whether the addition of neoadjuvant chemoradiotherapy ( NACRT ) to surgery can improve outcomes better than neoadjuvant chemotherapy in terms of rate of R0 resection, pathological complete response ( pCR ) and side effects. Methods This exploratory study included primary gastric adenocarcinoma patients staged as clinical T4N0 or anyTN1-3. Intensity modulated radiotherapy was delivered of 40 to 50 Gy in 22 to 25 fractions,5 days/week.Concurrent chemotherapy regimens included S-1 or Capecitabine or a combination of Paclitaxel plus Carboplatin.Results Eleven eligible patients were enrolled. R0 and R2 resections were performed in 9 ( 9/11) and 1 patients, respectively.Peritoneal metastasis was found in 1 case during exploratory laparotomy.The pCR was observed in 1 patient with R0 resection ( 1/10 ) . Ten cases completed radiotherapy and 8 cases completed chemotherapy. Nausea ( 3/11 ) , vomit ( 2/11 ) and anorexia ( 2/11 ) were the most common Grade 3 toxicities. Conclusions NACRT showed an acceptable toxicity and promising activity in locally advanced gastric adenocarcinoma.
ABSTRACT
According to the medical history,imaging and pathological diagnosis,the advanced gastric cancer patients able to tolerate radiotherapy can be divided into the following three groups:(1) unresectable locally advanced or locally recurrent disease;(2) metastatic disease at primary diagnosis with stage Ⅳ;(3) patients experiencing severe tumor-related clinical symptoms.The role of palliative radiotherapy in patients with advanced gastric cancer would be discussed by reviewing 33 articles (8 in last five years,13 in ten years).
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ObjectiveTo investigate the efficacy and toxicity of postoperative radiochemotherapy compared with chemotherapy alone in the treatment of locally advanced gastric cancer.MethodsA total of 83 patients with resected adenocarcinoma of the stomach were randomly assigned to postoperative radiochemotherapy group (RCT) ( n =43 ) or chemotherapy alone group (CT) ( n =40 ).Patients in RCT group received radiotherapy concurrent with capecitabine chemotherapy then followed by 4 - 6 cycles of FOLFOX4 chemotherapy.The total dose of radiation was 45 Gy.The dose of capecitabine was 1600 mg/m2per day.In the CT group,patients received 6 - 8 cycles FOLFOX4 chemotherapy.Survival was analyzed using Kaplan-Meier method and Logrank test. Results The follow-up rate was 96％. The number of patients who had a minimum of 2-,3-year follow-up time were 37,12 in the RCT group and 31,10 in the CT group.The 1-,2-,3-year local control rates for RCT and CT groups were 100％,97％,94％ and 95％,87％,73％ (x2 =4.54,P =0.033),respectively.The 1-,2-,3-year survival rates were 98％,86％,81％ in the RCT group,with 93％,80％,64％ in the CT group ( x2 =3.96,P =0.047 ).The incidence of grade 3hematological toxicity in the RCT and CT group was 23％ vs 15％ ( x2 =0.93,P =0.630 ),and grade 3gastrointestinal toxicity was 16％ vs 10％ ( x2 =0.95,P =0.624 ). Conclusions Compared with chemotherapy alone,postoperative radiochemotherapy can improve survival of locally advanced gastric cancer patients with acceptable toxicities.
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Objective To compare the dose distribution of the target and normal tissues in gastric cancers between three-dimension conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT) plan when respiratory motion factors integrated in the plan. Methods From January 2005to November 2006, 10 patients with post-operatively radiation of gastric cancer were enrolled in this study.Planning CT were acquired conventionally with free-breath mode and the static treatment plans of the 3DCRT and IMRT were designed respectively. Probability distribution functions (PDF) were generated and convoluted with the static dose distributions from 3DCRT and IMRT plans to obtain the integrated plans. The dose distributions of the target and normal tissues were compared between 3DCRT and IMRT integration treatment plans, such as V45 of clinical target volume, V4o of liver and V15, V18 of left and right kidney.Results In the respiratory integrated treatment planning, the target volume coverage and homogeneity with IMRT are superior to those with 3DCRT ( ( V45 98%∶ 87% (t = -3. 35 ,P =0. 010) ,mean dose 46. 81 Gy ±0. 75 Gy∶45.99 Gy ± 1.12 Gy (t = -0. 31 ,P=0. 020) ). The V40 of teh liver in IMRT are smaller than those in 3DCRT ( 12%∶ 16% ;t=3.75,P=0.010). For the left kidney, the V15 and V18 in IMRT are smaller than those in 3DCRT ( (34%∶ 50% (t = 2. 17 ,P = 0. 050) and 27%∶46% (t = 3. 11 ,P = 0. 020) ),but for the right kidney, V15 and V18 in 3DCRT are smaller than those in IMRT ( ( 15%∶ 21% (t = - 2. 42,P=0.040) and 11%∶15% (t= -2.71,P=0.030)). Conclusions When respiratory motion factor integrated in the treatment plan, IMRT showed advantage both in target coverage and normal tissue sparing in the high dose region of liver and left kidney.
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Objective To assess the impact of respiratory motion on the displacement of target area and to analyze the discrimination between free breathing and active breathing control (ABC) in patients with gastric cancer treated with post-operative radiotherapy. Methods From January 2005 to November 2006, 22 patients with post-operatively confirmed gastric cancer were enrolled in this study. All diseases were T_3/ N +, staging Ⅱ - Ⅳ. Patients were CT scanned and treated by radiation with the use of ABC. Image J software was used in image processing, motion measurement and data analysis. Surgical clips were implanted as fiducial marks in the tumor bed and lymphatic drainage area. The motion range of each clip was measured in the resultant-projection image. Motions of the clips in superior-inferior (S-I), right-left (R-L) and anterior-posterior (A-P) directions were determined from fluoroscopy movies obtained in the treatment position. Results The motion ranges in S-I, R-L and A-P directions were 11.1 mam, 1.9 mm and 2.5 mm (F = 85.15, P = 0. 000) under free breathing, with 2.2 mm, 1.1 mm and 1.7 nun under ABC (F = 17.64, P = 0. 000), and the reduction of motion ranges was significant in both S-I and A-P directions (t = 4.36, P = 0. 000;t = 3.73,P = 0.000). When compared with under free-breathing, the motion ranges under ABC were kept unchanged in the same breathing phase of the same treatment fraction, while significant increased in different breathing phase in all three directions (t = - 4.36, P = 0. 000; t = - 3.52, P = 0.000; t =-3.79, P = 0. 000), with a numerical value of 3.7 mm, 1.6 mm and 2.8 mm, respectively (F = 19.46, P = 0. 000) . With ABC between different treatment fractions , the maximum displacements were 2.7 mm, 1.7 mm and 2.5 mm for the centre of the clip cluster (F =4.07,P =0. 019), and were 4.6 mm, 3.1 mm and 4.2 mm for the clips (F =5.17 ,P =0.007). The motion ranges were significant increased in all the three directions (t = - 4.09, P=0.000 ; t =-4.46, P = 0.000 ; t = - 3.45, P =0.000). Conclusions In the irradiation of post-operative gastric cancer, the maximum displacement of organ motions induced by respiration is in S-1 direction and the minimum in R-L direction under free breathing. The use of ABC can reduce the motions significantly in S-I and A-P directions, and the same changes exist in both inter-and intra-fraction treatment.
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Purpose:To evaluate the safety and efficacy of the box-shape field technique of radiotherapy for postoperative gastric carcinoma.Methods:Thirty-two patients of gastric carcinoma after subtotal or total gastrectomy with an extensive (D2) lymph-node dissection were irradiated with a total dose of 46～50Gy Gy of external box-shape field technical in 23-25 fractions by linac with 6-MV photons. All patients received concomitant chemotherapy which two cycles of paclitaxel (135mg/m~2 ) and cisplatin (70mg/m~2) in d1-3 and d29-31.Results:The overall survival,the relapse free survival of two years of all patients was 87.50% and 16.67%, respectively. 32 patients with treatment failure had recurrent disease, 4 (6.3%)in the liver,2(6.3%) in the peritoneum, 2(12.5%) in the anastomosis ,respectively. the plan of box-shape fields were evaluated with dose-volume histogram of three-dimensional therapy plan system, The 90% isodose line included the whole clinical target volume,and the dose of organat at rist was under the tolerance dose, except the dose of left kidney.Conclusions:The box-shape field technique of radiotherapy for postoperative gastric carcinoma were a technique which the dose distribution of clinical target volume was satisfaction ,and well tolerated with no severe side effects.[