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469 Background: To evaluate the effectiveness of H-IMRT and VMAT in covering target volume while adequately sparing the OARs for patients with mid and distal oesophageal carcinoma, on the basis of dosimetric analysis. Methods: The target areas and organs at risk in 30 patients with locally advanced carcinoma oesophagus undergoing neo-adjuvant chemo-radiotherapy were specified and transmitted to Eclipse, Version 13.6, Varian Medical Systems) & Accuray Treatment Planning System (Accuray Precision, Version 2.1.4, Accuray Medical System). Two plans (H-IMRT and VMAT) were generated for each patient for a total dose of 41.4 Gy delivered to the PTV in 23 fractions, and the Homogeneity Index (HI), Conformity Index (CI) and the dose distribution to the OARs (spinal cord, heart, lungs, kidneys and liver) were compared using dose volume histograms. Results: H-IMRT resulted in a more homogeneous dose distribution to the target (HI- 0.059) as compared to VMAT (HI- 0.07) [p-0.004]. The Conformity Indices showed no significant difference between the two techniques (H-IMRT – 0.989, VMAT – 0.987) [p-0.66]. VMAT resulted in a significantly less dose to the spinal cord (23.598 Gy vs .25.657 Gy) [p-0.021]. With VMAT plans, the heart mean dose (18.101 Gy vs. 20.031) [p- 0.00007], heart V40 (4.902% vs. 6.143) [p-0.002,] the averaged lung V20 [p-0.00005] and the mean dose to the left kidney (3.84 Gy vs. 4.721 Gy) [p- 0.010] were significantly less as compared to H-IMRT No statistically significant difference in both techniques with respect to heart V30, Mean Lung Dose (MLD), and mean dose to the righ and left kidney was observed Conclusions: VMAT proved to be better at sparing of OARs whilst providing almost the same Conformity as compared to a H-IMRT. H-IMRT has statistically better dose homogeneity but, it tends to deposit a slightly higher dose to the OARs. Whether the aforementioned differences in the dosimetric parameters translate into clinical benefits has to be evaluated by clinical outcome studies.

IntroductionThere are standard treatment guidelines for the surgical management of rectal cancer, that are advocated by recognized physician societies. But, owing to disparities in access and affordability of various treatment options, there remains an unmet need for personalizing these international guidelines to Indian settings.MethodsClinical Robotic Surgery Association (CRSA) set up the Indian rectal cancer expert group, with a pre-defined selection criterion and comprised of the leading surgical oncologists and gastrointestinal surgeons managing rectal cancer in India. Following the constitution of the expert Group, members identified three areas of focus and 12 clinical questions. A thorough review of the literature was performed, and the evidence was graded as per the levels of evidence by Oxford Centre for Evidence-Based Medicine. The consensus was built using the modified Delphi methodology of consensus development. A consensus statement was accepted only if ≥75% of the experts were in agreement.ResultsUsing the results of the review of the literature and experts’ opinions; the expert group members drafted and agreed on the final consensus statements, and these were classified as “strong or weak”, based on the GRADE framework.ConclusionThe expert group adapted international guidelines for the surgical management of localized and locally advanced rectal cancer to Indian settings. It will be vital to disseminate these to the wider surgical oncologists and gastrointestinal surgeons’ community in India.