Bridging the Gap in Access to Radiotherapy in Low- and Middle-Income Countries Using a Co-Compensator Based IMRT Device: A Treatment Planning System Study of Head & Neck and Cervical Cases
B Sengupta1*, K Oh2, P Zaki3, P Sponseller4, C Cardenas5, L Court6, E Ford7, (1) University of Washington, Seattle, WA, (2) University of Washington, Sugar Land, TX, (3) University Of Washington, ,,(4) University of Washington, Seattle, WA, (5) The University of Alabama at Birmingham, Birmingham, AL, (6) UT MD Anderson Cancer Center, Houston, TX, (7) University of Washington, Seattle, WA
Presentations
MO-F-202-2 (Monday, 7/11/2022) 1:45 PM - 2:45 PM [Eastern Time (GMT-4)]
Room 202
Purpose: Capital equipment and maintenance costs are major causes for limited RT access in low- and middle-income countries. We are developing a novel cobalt-compensator based IMRT device that can provide cost-effective and reliable RT in limited-resource settings. The goal of this work is to investigate the quality of treatment plans.
Methods: Cobalt beam data from Monte Carlo(MC) simulation was used for beam-commissioning within the treatment planning system (TPS) and for plan validation. Thirty clinical head & neck and cervical cancer cases were planned and compared with a 6 MV linac using IMRT. Patient-specific compensators were created within the TPS as regions-of-interests.
Results: Dose coverage of targets and OAR sparing was comparable to clinical plans using a 6MV linac. OAR sparing was similar to clinical plans (e.g. parotid gland mean dose 2600 cGy). PTV objectives were achieved in all 30 plans with PTV V95% > 95%. Dmax < 45 Gy for spinal cord was achieved in 25 cases. Initial data on cervical cases suggests bowel sparing similar to clinical plans, with V15 < 195 cc. The average field-by-field gamma pass rate was 93.7% (2%/2mm). Estimated treatment times using the Co-60 compensator device was similar to the times from the clinical plans with an average radiation delivery time of 1 min 27 seconds vs 1 min 2 seconds for the clinical system.
Conclusion: This system is the first of its kind to allow for IMRT with a Co-60 device. Plan quality criteria were met while maintaining short treatment times which may offer a sustainable and cost-effective option for IMRT on the global scale.
Funding Support, Disclosures, and Conflict of Interest: This work was supported by the National Cancer Institute of the National Institutes of Health under Award Number 5UH3 CA211310-04
Keywords
Co-60, Compensators, Intensity Modulation
Taxonomy
TH- External Beam- Photons: Development (new technology and techniques)
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