ESTRO 2022 - Abstract Book

S1663

Abstract book

ESTRO 2022

Results Delivery of SABR (30Gy in 3 fractions over 6 days) to a gluteal oligometastasis was successfully completed on the Unity MRL following the Adapt to Position (ATP) workflow. Target visualisation on pMR was superior to pCT, in which the 8mm lesion was barely visible (Figure 1). Consensus review showed that the 6 minute T2 3D Tra sequence provided superior confidence in target visibility and was therefore used for planning and daily plan adaptation/verification. Median treatment time was 52:08 (range 49:19 - 57:16). The patient did not report any adverse effects.

Conclusion We have successfully completed SABR delivery to a sub-centimetre oligometastasis within the right gluteus medius muscle on the Elekta Unity MRL following the ATP workflow, a first at our institution. This would not have been possible on a conventional linac due to the poor soft-tissue contrast associated with CT and CBCT imaging. Workflows have been established that will facilitate a future MR guided, soft tissue tumour service.

PO-1878 Dosimetric importance of Jaw tracking in Intensity modulated Radiotherapy

H. V T 1 , H. VT 2 , D. Khanna 2 , A. Raj 1,2 , S. P 1

1 Aster Malabar Institute of Medical Sciences, Oncology, Calicut, India; 2 Karunya Institute of Technology and Sciences, Physics, Coimbatore, India Purpose or Objective The main aim of this study was to show the dosimetric importance of Jaw tracking technique in reducing the doses to organs at risk while achieving the optimal target dose coverage. Materials and Methods A retrospective study of 10 GBM cases where two plans were created for each patient, Static Jaw Technique (SJT) Dynamic Intensity Modulated Radiotherapy (D-IMRT) plan and Jaw Tracking Technique (JTT) D-IMRT plan. Both plans were created