Concurrent Chemoradiotherapy As Adjuvant Treatment For Locally Advanced Gastric Cancer And A Dosimetric Comparison Of Intensity-Modulated Radiotherapy (IMRT), Volumetric-Modulated Arc Therapy (VMAT) And Tomotherapy (TOMO)

Interim Assessment of Phase â…¡ Study of Concurrent S-1 and Intensity Modulated Radiotherapy as Adjuvant Treatment for Locally Advanced Gastric CancerObjective This phase â…¡ trial aimed to investigate the efficacy and safety of S-1 with concomitant intensity modulated radiotherapy (IMRT) as an adjuvant treatment for lymph node-positive gastric cancer.Methods We consecutively enrolled patients with pathologically proved lymph node-positive gastroesophageal or gastric adenocarcinoma (anyTN+MO) after complete resection with negative margins (R0). IMRT was delivered of 45 Gy (1.8 Gy/fraction,5 days/week). S-1 was administered every weekday at a dosage of 80mg/m2/d, as a result of our previously phase â…  study.Results From March 2013 to December 2014, forty patients were consecutively recruited (3 with stage â…¡,37 with stage â…¢, AJCC 7th). The median age was 50 years old (range 27-73) and the male to female ratio was 3:1. D2 lymphadenectomy were performed in 33 patients and the rest underwent D1 lymphadenectomy. The median number of dissected lymph nodes was 36 (range 14-79) with median positive lymph nodes of 11 (range 1-45). Thirty nine patients completed radiotherapy and thirty five completed concomitant chemotherapy. Grade 3-4 toxicities were:nausea/anorexia (5 patients, 12.5%), leukopenia (4 patients,10.0%), vomiting (3 patients,7.5%), esophagitis (2 patients,5%) and neutropenia (2 patients,5%). No patients occurred liver or kidney dysfunction or died within 30 days after chemoradiotherapy. The 2-year overall survival, disease free survival74.3%,77.2%.Conclusions S-1 with concurrent IMRT was feasible and tolerable for lymph node-positive gastric cancer patients as an adjuvant setting.A dosimetric comparison of Intensity-Modulated Radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and Tomotherapy (TOMO) for adjuvant treatment of gastroesophageal junction cancerObjective To compare dosimetric parameters of intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and Tomotherapy (TOMO) in adjuvant treatment for gastroesophageal junction (GEJ) adenocarcinoma.Methods Nine patients with GEJ cancer undergoing proximal partial gastrectomy (PPG) or total gastrectomy (TG) were re-planned by coplanar IMRT (five fixed beam), VMAT (double-arc) and TOMO. A total dose of 45Gy was delivered concurrently with S-1 at a dosage of 80mg/m2/d orally taken in radiotherapy treatment days. The irradiated bowel volumes and the bone marrow (BM) were kept as low as possible. The target parameters as well as doses to the organs at risk (OARs) were analyzed to compare treatment plans.Results TOMO provided significantly greater homogeneity and conformity and better sparing of the bowel and BM over IMRT and VMAT. In addition, TOMO also resulted in fulfilling the OARs constraints to the lungs and heart. VMAT achieved significantly lower V20 of the left kidney and V30 of the heart for all patients. Meanwhile, VMAT also created lower total MU compared to TOMO and IMRT. IMRT deposited the lowest V5, V10 of the lungs but did not create a superiority of V20 and mean lung dose compared to TOMO and VMAT.Conclusions In comparison with IMRT and VMAT, TOMO is a good option for treating GEJ cancer patients undergoing PPG or TG as it achieves superior bowel and BM sparing and acceptable dose to the lungs and the heart while maintaining the best dose conformity and homogeneity.