ESTRO 2023 - Abstract Book

S2026

Digital Posters

ESTRO 2023

These results suggest a potential set-up benefit using the IntegraBite™ to reduce setup errors both in relation to bony anatomy and the hypopharynx. Initial results suggest the potential benefit is not as prominent for patients receiving radiotherapy to the oropharynx. Further work is needed to determine the potential for reduced margins, in particular patients receiving radiotherapy to the larynx where larger margins are often used to account for inter fractional variations as a result of swallowing.

PO-2252 Evaluation of activated breath control and surface guided radiotherapy in breast cancer.

S. Raby 1 , C. Anandadas 1 , T. Awofisoye 1 , J. Kelly 1

1 The Christie, Clinical Oncology, Manchester, United Kingdom

Purpose or Objective The UK HeartSpare study ¹ has previously compared voluntary and ABC techniques of DIBH in 23 patients prospectively and found that they are comparable in terms of positional reproducibility and normal tissue sparing. However, voluntary DIBH is preferred by patients and radiographers and takes less time to deliver. There are no previous studies comparing ABC with SGRT techniques of DIBH. We aimed to compare ABC and SGRT techniques as a pilot study at the Christie in 2 patient cohorts receiving adjuvant radiotherapy following a diagnosis of localised breast cancer, to assess the feasibility, reproducibility, dosimetric and patient experience outcomes. Materials and Methods Both techniques are currently fully available at the Christie. We recruited 10 SGRT and 14 ABC patients. We devised a proforma to obtain: 1) timings of i) Pre-treatment (including coaching time if applicable), ii) RTP acquisition time, iii) set-up time (time from set up of equipment to beam on (excluding the 3 field)) and iv) treatment time (beam on to off). We additionally recorded number of moves required during treatment, mean heart dose and lung depth on both the low and high dose RTP scans. Results All patients had left sided breast tumours and were well matched for all baseline demographics. There was no difference between ABC and SGRT for set-up time RTP acquisition, treatment time, mean heart dose, and lung depth (mean, range vs mean range). Both pre-treatment time and number of moves required (mean range vs mean range) were greater with ABC than SGRT. At 5 fractions, overall time (pre-treatment and then 5 fractions) was 136 mins for SGRT vs 177.5 for ABC, p=0.08, For 15 fractions, it was 351 vs 422.5 mins, p=0.14. 2) Questionnaire of patient satisfaction (comfort and reproducibility) 3) Questionnaire of radiographer satisfaction (comfort, reproducibility, feasibility)

Patient satisfaction was matched across both groups with no significant difference seen for any of the questions asked. Radiographer satisfaction was matched for the majority of questions. There was a significant difference with satisfaction related to difficulty in use of equipment with more radiographers ranking the ABC equipment a little difficult to use (64% vs 17%, p < 0.05) Conclusion SGRT, as compared to ABC techniques of DIBH in adjuvant treatment of patients with localised breast cancer, has a significantly shorter pre-treatment time and number of set-up moves during treatment. It provides a better radiographer and patient experience without compromising the doses to the heart. We will have more confidence to phase out ABC as a DIBH technique in the Christie. 1. Bartlett FR, Colgan RM, Carr K, et al. The UK HeartSpare Study: randomised evaluation of voluntary deep-inspiratory breath-hold in women undergoing breast radiotherapy. Radiotherapy and Oncology:Journal of the European Society for Therapeutic Radiology and Oncology. 2013 Aug;108(2):242-247.