ESTRO meets Asia 2024 - Abstract Book

S55

Interdisciplinary – Brachytherapy

ESTRO meets Asia 2024

Results:

In all 16 instances, the double balloon was selected as the best plan for treatment based on individual patient assessment in real-time. The volumes of TV and OARs were similar in the three scans. DB use consistently and significantly improved TV coverage for D100% compared to NB & NB (NB: 5.14, SB: 5.18 and DB: 5.66 Gy; p=0.01; 10% each). Very high dose spots were reduced in TV for D0.1cc (sequentially for additional balloons; NB, SB & DB as 20, 18.5 & 16.5 Gy respectively; 11 & 17% reduction; p=0.001), for V200% (only DB as 20.5%, 15.9% and 10.3%; p=0.01). The presence of SB or DB similarly reduced the rest of the rectum doses but significantly from NB state by 15-25% (D0.1cc: p=0.01, D1cc: p=0.02, and D2cc: p=0.04). Other OARs received very low doses in NB state to be further affected by the use of balloons.

Conclusion:

The use of endocavity SB and DB significantly improved the sparing of the normal rectal mucosa over NB but were similar among themselves. DB improved the target coverage better than SB over NB, thus providing the best therapeutic ratio and clinical plan choice. Hence, currently, we use and recommend DB for all endorectal brachytherapy insertions for rectal cancer.

Keywords: RECTAL CANCER, BRACHYTHERAPY, DOSE ESCALATION

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Digital Poster

Dosimetry Analysis of OAR in HDR IBT Treatment for Liver Malignancy with Iridium-192 Source

Keerthaanaa Yogabalan 1 , Gokula Kumar Appalanaido 1,2 , Mohd Zahri Abdul Aziz 1,3 , Jayapramila Jayamani 4 , Jasmin Jalil 2 , Reduan Abdullah 5 , Nor Hafizah Ishak 2 , Nursyatina Abdul Raof 2 , Ahamed Badusha Mohamed Yoosuf 6 , Mamdouh Alqathami 6 1 Advanced Management of Liver Malignancies Program, Universiti Sains Malaysia, Advanced Medical and Dental Institute, Penang, Malaysia. 2 Radiotherapy Unit,, Pusat Perubatan Universiti Sains Malaysia PPUSMB, Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia,, Penang, Malaysia. 3 Department of Biomedical Imaging, Universiti Sains Malaysia, Advanced Medical and Dental Institute, Penang, Malaysia. 4 Medical Radiation Programme,, Universiti Sains Malaysia, School of Health Science, Kelantan, Malaysia. 5 Department Of Nuclear Medicine, Radiotherapy & Oncology, Universiti Sains Malaysia, Hospital Universiti Sains Malaysia, Kelantan, Malaysia. 6 Department of Oncology,, King Abdullah International Medical Research Center,, Riyadh,, Saudi Arabia