95P Radiotherapy (RT) for breast cancer patients- clinical implementation of the first ever Tomotherapy-H in a tertiary cancer centre in India

Abstract

Background The first ever Tomotherapy-H system in India became operational in Feb 2016 in our hospital, Health care global enterprises, a tertiary level cancer care centre. In order to implement Tomotherapy as a routine technique to treat breast cancers we under took dosimetric comparison of helical Tomotherapy plans and five field forward planning intensity modulated radiotherapy (IMRT) plans. Methods We compared the Helical Tomotherapy plans with IMRT plans of the first 10 patients with early breast cancer who underwent adjuvant RT using helical Tomotherapy technique in our centre between February 2016 and June 2016. The treatment planning objectives were to cover 95% of the planning target volume (PTV) using a 95% isodose (V95 >/= 95%), with a minimum of 90% isodose covering 100% of PTV (V100 >/= 90%) and no more than 10% ofPTV to receive 110% (V110 <10%). The heart and lungs were contoured as organs at risk (OAR) and doses received were recorded in both the planning techniques. Results All patients were females with four right and six left sided cancers. Seven patients had undergone breast conserving surgery and three had mastectomy. When we compared the forward planning IMRT plans with Helical Tomotherapy plans, we found thattheadvantageofusingHelicalTomotherapyincludedsignificantlybettercoverage forV95(p<0.000),V100(p<0.000)andmedianV110was0.06%and0.14%in Helical Tomotherapy and IMRT plans respectively. Helical Tomotherapy plans had lower dose to ipsilateral lung (V35 P < 0.01) and lower median dose to the heart (Tomotherapy=8.2andIMRT=9Gy).Therewasimprovedcoverageoftheplanning target volume, including the regional nodes, without any field junction problems. None ofthepatientshadanymorethangrade1 skintoxicityandgrade1 oesophagitis. Conclusions Helical Tomotherapy, compared to forward planning IMRT for breast cancer treatment, demonstrated better target coverage and sparing ofOARs. The treatment was well tolerated with minimal toxicity. Long term toxicity is yet to be established by continued follow up ofthese patients in late side effects clinics. Legal entity responsible for the study Health Care Global Enterprises Funding Health Care Global Enterprises Disclosure All authors have declared no conflicts ofinterest.