Intensity Modulated Proton Therapy Treatment Planning for Postmastectomy Patients with Metallic Port Tissue Expanders.
Adv Radiat Oncol
; 7(1): 100825, 2022.
Article
em En
| MEDLINE
| ID: mdl-34805622
ABSTRACT
PURPOSE:
Proton beam therapy can significantly reduce cardiopulmonary radiation exposure compared with photon-based techniques in the postmastectomy setting for locally advanced breast cancer. For patients with metallic port tissue expanders, which are commonly placed in patients undergoing a staged breast reconstruction, dose uncertainties introduced by the high-density material pose challenges for proton therapy. In this report, we describe an intensity modulated proton therapy planning technique for port avoidance through a hybrid single-field optimization/multifield optimization approach. METHODS AND MATERIALS In this planning technique, 3 beams are utilized. For each beam, no proton spot is placed within or distal to the metal port plus a 5 mm margin. Therefore, precise modeling of the metal port is not required, and various tissue expander manufacturers/models are eligible. The blocked area of 1 beam is dosimetrically covered by 1 or 2 of the remaining beams. Multifield optimization is used in the chest wall target region with blockage of any beam, while single-field optimization is used for remainder of chest wall superior/inferior to the port.RESULTS:
Using this technique, clinical plans were created for 6 patients. Satisfactory plans were achieved in the 5 patients with port-to-posterior chest wall separations of 1.5 cm or greater, but not in the sixth patient with a 0.7 cm separation.CONCLUSIONS:
We described a planning technique and the results suggest that the metallic port-to-chest wall distance may be a key parameter for optimal plan design.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Idioma:
En
Revista:
Adv Radiat Oncol
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Geórgia