ESTRO 2024 - Abstract Book

S5976

RTT - Treatment planning, OAR and target definitions

ESTRO 2024

Two atlases were created: Craniospinal_Adult_Atlas (Atlas1) and Craniospinal_PaedYA_Atlas (Atlas2). ABI was attempted for the following targets and OARs: whole brain, optic nerves, cervical, thoracic and lumbar spine, adjacent vertebrae, optic chiasm, globes, lenses, parotids, cochlea’s, kidneys, lungs, heart, liver, thyroid gland and oesophagus. Atlas1 included 23 anonymised image sets (Adults). Atlas2 included an additional ‘Vertebral Body Adjacent’ structure for 27 anonymised image sets (paediatric and young adults). Quality of auto contours was compared to SIOPE consensus atlas for CSI target volume delineation [1] with institutional peer review and local OAR contouring guidelines. Final atlases included automation of all CTVs and the following OARs: Chiasm, Globes, Lenses, Cochlea’s, Kidneys, Lungs, Heart, Liver and Thyroid.

Results:

The quality of the auto contours was deemed clinically acceptable prior to minor manual editing except for oesophagus and parotids which were not contoured accurately. Median segmentation time for both atlases was 11 minutes (range, 10-15 minutes). Following minor edits, median delineation time was 110 minutes (range, 107 – 117 minutes) and 99 minutes (95 minutes – 105 minutes) for Atlas1 and Atlas2 respectively.

Conclusion:

Both Atlas’s are now implemented clinically for paediatric and adult CSI-VMAT, providing valuable time saving tools for the planning of these patients. Contours are subject to final clinician approval. Potentially, the atlases could be applied to Proton Therapy or other highly conformal radiotherapy treatments for children and adults.

Keywords: Atlas-based segmentation, CNS, VMAT

References:

Ajithkumar T, Horan G, Padovani L, et al. SIOPE – Brain tumor group consensus guideline on craniospinal target volume delineation for high-precision radiotherapy. Radiother Oncol. 2018;128:192-197. https://doi.org/10.1016/j.radonc.2018.04.016

1658

Digital Poster

Predictive anatomic factors of heart doses in left-sided breast RT: Do breast size and shape matter?

Zeineb Naimi, Amal Riahi, Meriem Bohli, Raouia Ben Amor, Ghada Bouguerra, Awatef Hamdoun, Lotfi Kochbati

Abderrahmen Mami Hospital Ariana, Radiation Oncology Department, Ariana, Tunisia

Purpose/Objective: