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SU‐E‐T‐215: Interactive Dose Shaping: Proof of Concept Study for Six Prostate Patients
Author(s) -
Kamerling CP,
Ziegenhein P,
Sterzing F,
Oelfke U
Publication year - 2014
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4888545
Subject(s) - radiation treatment planning , medicine , medical physics , proof of concept , prostate , isocenter , nuclear medicine , dosimetry , voxel , plan (archaeology) , computer science , radiology , radiation therapy , imaging phantom , operating system , history , archaeology , cancer
Purpose: To provide a proof of concept study for IMRT treatment planning through interactive dose shaping (IDS) by utilising the respective tools to create IMRT treatment plans for six prostate patients. Methods: The IDS planning paradigm aims to perform interactive local dose adaptations of an IMRT plan without compromising already established valuable dose features in real‐time. Various IDS tools are available in our in‐house treatment planning software Dynaplan and were utilised to create IMRT treatment plans for six patients with an adeno‐carcinoma of the prostate. The sequenced IDS treatment plans were compared to conventionally optimised clinically approved plans (9 beams, co‐planar). The starting point consisted of open fields. The IDS tools were utilised to sculpt dose out of the rectum and bladder. For each patient, several IDS plans were created, with different trade‐offs between organ sparing and target coverage. The reference dose distributions were imported into Dynaplan. For each patient, the IDS treatment plan with a similar or better trade‐off between target coverage and OAR sparing was selected for plan evaluation, guided by a physician. Pencil beam dose calculation was performed on a grid with a voxel size of 1.95×1.95×2.0 mm 3 . D98%, D2%, mean dose and dose‐volume indicators as specified by Quantec were calculated for plan evaluation. Results: It was possible to utilise the software prototype to generate treatment plans for prostate patient geometries in 15–45 minutes. Individual local dose adaptations could be performed in less than one second. The average differences compared to the reference plans were for the mean dose: 0.0 Gy (boost) and 1.2 Gy (CTV), for D98%: −1.1 Gy and for D2%: 1.1 Gy (both target volumes). The dose‐volume quality indicators were well below the Quantec constraints. Conclusion: Real‐time treatment planning utilising IDS is feasible and has the potential to be implemented clinically. Research at The Institute of Cancer Research is supported by Cancer Research UK under Programme C46/A10588.