ESTRO 2023 - Abstract Book

S1779

Digital Posters

ESTRO 2023

D50 (%)

117 ± 5

118 ± 5

D2cc (R Eye) (%) 3 ± 2 D2cc (L Eye) (%) 6 ± 5

4 ± 1 8 ± 5

The presence of bolus increased the values of CTV coverage and dosimetric parameters, with a maximum value in CTV coverage similar to the one obtained in TG43 calculations. (Figure 2 shows an example of bolus)

Conclusion The current work investigated the performances of a MBDCA for skin IRT. No significant differences were found for clinically important dosimetric parameters. The calculation time and the CTV coverage for the five patients linearly increase with the number of active dwell positions. To increase the CTV coverage it is possible to increase the water bolus thickness with a maximum value of the CTV coverage similar to the one calculated through TG-43 formula. Re-evaluation of the clinical results based on long-term effects on TG43 is needed to introduce ACE algorithm to clinical practice.

PO-2007 Organs at Risk dose analysis for rectal cancer short-course radiotherapy

F. Sansaloni 1 , E. Recalde 2 , B. Navalpotro 2

1 Vall d'Hebron Hospital, Medical Physics, Barcelona, Spain; 2 Vall d'Hebron Hospital, Radiation Oncology Department, Barcelona, Spain Purpose or Objective Total neoadjuvant therapy (TNT) is a novel approach to locally advanced rectal cancer (LARC) that has increased the number of patients treated with short course radiotherapy (SCRT). There is lack of clinical evidence and literature on OARs constraints for SCRT, where constraints are calculated from LCRT using linear quadratic model and also optimizing the dose to OARs. We aimed to review the dosimetric data that OARs received in patients treated whit SCRT in our institution and try to develop in house dose optimization objectives.

Materials and Methods