Target tailoring and proton beam therapy to reduce small bowel dose in cervical cancer radiotherapy: A comparison of benefits

Purpose The aim of the study was to investigate the potential clinical benefit from both target tailoring by excluding the tumour-free proximal part of the uterus during image-guided adaptive radiotherapy (IGART) and improved dose conformity based on intensity-modulated proton therapy (IMPT). Method...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Strahlentherapie und Onkologie 2018-03, Vol.194 (3), p.255-263
Hauptverfasser: de Boer, Peter, van de Schoot, Agustinus J. A. J., Westerveld, Henrike, Smit, Mark, Buist, Marrije R., Bel, Arjan, Rasch, Coen R. N., Stalpers, Lukas J. A.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Purpose The aim of the study was to investigate the potential clinical benefit from both target tailoring by excluding the tumour-free proximal part of the uterus during image-guided adaptive radiotherapy (IGART) and improved dose conformity based on intensity-modulated proton therapy (IMPT). Methods The study included planning CTs from 11 previously treated patients with cervical cancer with a >4-cm tumour-free part of the proximal uterus on diagnostic magnetic resonance imaging (MRI). IGART and robustly optimised IMPT plans were generated for both conventional target volumes and for MRI-based target tailoring (where the non-invaded proximal part of the uterus was excluded), yielding four treatment plans per patient. For each plan, the V 15Gy , V 30Gy , V 45Gy and D mean for bladder, sigmoid, rectum and bowel bag were compared, and the normal tissue complication probability (NTCP) for ≥grade 2 acute small bowel toxicity was calculated. Results Both IMPT and MRI-based target tailoring resulted in significant reductions in V 15Gy , V 30Gy , V 45Gy and D mean for bladder and small bowel. IMPT reduced the NTCP for small bowel toxicity from 25% to 18%; this was further reduced to 9% when combined with MRI-based target tailoring. In four of the 11 patients (36%), NTCP reductions of >10% were estimated by IMPT, and in six of the 11 patients (55%) when combined with MRI-based target tailoring. This >10% NTCP reduction was expected if the V 45Gy for bowel bag was >275 cm 3 and >200 cm 3 , respectively, during standard IGART alone. Conclusions In patients with cervical cancer, both proton therapy and MRI-based target tailoring lead to a significant reduction in the dose to surrounding organs at risk and small bowel toxicity.
ISSN:0179-7158
1439-099X
DOI:10.1007/s00066-017-1224-8