ESTRO meets Asia 2024 - Abstract Book

S64

Interdisciplinary – Brachytherapy

ESTRO meets Asia 2024

The median follow-up is 17 months (m) ranging from 12 to 40 m. The average MS thickness in this study is 0.7cm (range: 0.4 – 1cm) is used as the cut-off point for data analysis. All patients received 4 Gy x 5 twice-daily fractions of HDRIBT followed by 69.96 Gy in 33 fractions of IMRT with concurrent chemotherapy within 10 days after completing the HDRIBT. There were 3 grade 1 and 5 grade 2 ORN at the PLM with median time for ORN diagnosis of 21 m (range: 6 to 30 m). The ORN region range at PLM based on the common dental nomenclature of tooth number (preceding number: 3 is left, 4 is right) is 36 – 38 (left side) and 44 – 48 (right side). The mean of AOI dose for HDRIBT and cumulative dose of HDRIBT plus IMRT with the EqD2 to ALM with MS and PLM without MS is presented in table 1.

Conclusion:

While the use of MS is very effective for ORN prevention in the ALM, the PLM remains an issue with HDRIBT for TSCC. This study shows that an average of 7mm MS thickness is sufficient to completely prevent ORN at the ALM. No ORN occurred when cumulative D 0.5cc and D 0.2cc of HDRIBT + IMRT EqD2 dose are below 81 Gy and 86.8 Gy respectively. Improvement in MS that covers the PLM, dose constraining of the PLM during IMRT planning and optimal patient selection will reduce the incidence of ORN with this HyBIRT technique.

Keywords: Mandible, Osteoradionecrosis, Cumulative dose

References:

1. Appalanaido G, Musa M, Chng E, Shukor SA, Chong S, Noor SM, et al. OC-0631 Upfront HDRIBT followed by IMRT for the Definitive Treatment of Tongue SCC. Radiotherapy and Oncology. 2023;182:S520-S1.

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Digital Poster

Comparative Analysis of Dysphagia Relief with EBRT Vs EBRT F/B ILRT in Advanced Esophageal Cancer

Dr Shreya Jain 1 , Dr Ashutosh Mukherji 2 , Dr Ajay choubey 2 , Dr Sambit Swarup Nanda 3 , Ajay S Krishnan 3 , Ninad H Patil 3 1 Radiation oncology, Tata Medical college, Varanasi, India. 2 Radiation oncology, Tata Tata Memorial Center, Varanasi, India. 3 Radiation oncology, Tata Memorial Center, Varanasi, India