Patient-specific Quality Assurance of Dynamically-collimated Proton Therapy Treatment Plans

Overview

Journal Med Phys

Specialty Biophysics

Date 2024 Jul 8

PMID 38977285

Authors

Laura C Bennett

Daniel E Hyer

Justin Vu

Kaustubh Patwardhan

Kevin Erhart

Alonso N Gutierrez

Eduardo Pons

Eric Jensen

Manual Ubau

Julio Zapata

Andrew Wroe

Karsten Wake

Nicholas P Nelson

Wesley S Culberson

Blake R Smith

Patrick M Hill

Ryan T Flynn

Affiliations

Soon will be listed here.

Abstract

Background: The dynamic collimation system (DCS) provides energy layer-specific collimation for pencil beam scanning (PBS) proton therapy using two pairs of orthogonal nickel trimmer blades. While excellent measurement-to-calculation agreement has been demonstrated for simple cube-shaped DCS-trimmed dose distributions, no comparison of measurement and dose calculation has been made for patient-specific treatment plans.

Purpose: To validate a patient-specific quality assurance (PSQA) process for DCS-trimmed PBS treatment plans and evaluate the agreement between measured and calculated dose distributions.

Methods: Three intracranial patient cases were considered. Standard uncollimated PBS and DCS-collimated treatment plans were generated for each patient using the Astroid treatment planning system (TPS). Plans were recalculated in a water phantom and delivered at the Miami Cancer Institute (MCI) using an Ion Beam Applications (IBA) dedicated nozzle system and prototype DCS. Planar dose measurements were acquired at two depths within low-gradient regions of the target volume using an IBA MatriXX ion chamber array.

Results: Measured and calculated dose distributions were compared using 2D gamma analysis with 3%/3 mm criteria and low dose threshold of 10% of the maximum dose. Median gamma pass rates across all plans and measurement depths were 99.0% (PBS) and 98.3% (DCS), with a minimum gamma pass rate of 88.5% (PBS) and 91.2% (DCS).

Conclusions: The PSQA process has been validated and experimentally verified for DCS-collimated PBS. Dosimetric agreement between the measured and calculated doses was demonstrated to be similar for DCS-collimated PBS to that achievable with noncollimated PBS.

References

Wang D, Dirksen B, Hyer D, Buatti J, Sheybani A, Dinges E . Impact of spot size on plan quality of spot scanning proton radiosurgery for peripheral brain lesions. Med Phys. 2014; 41(12):121705. DOI: 10.1118/1.4901260. View

Moteabbed M, Yock T, Depauw N, Madden T, Kooy H, Paganetti H . Impact of Spot Size and Beam-Shaping Devices on the Treatment Plan Quality for Pencil Beam Scanning Proton Therapy. Int J Radiat Oncol Biol Phys. 2016; 95(1):190-198. PMC: 4834139. DOI: 10.1016/j.ijrobp.2015.12.368. View

Nelson N, Culberson W, Hyer D, Geoghegan T, Patwardhan K, Smith B . Integration and dosimetric validation of a dynamic collimation system for pencil beam scanning proton therapy. Biomed Phys Eng Express. 2023; 9(6). PMC: 11128250. DOI: 10.1088/2057-1976/ad02ff. View

Zhu X, Li Y, Mackin D, Li H, Poenisch F, Lee A . Towards effective and efficient patient-specific quality assurance for spot scanning proton therapy. Cancers (Basel). 2015; 7(2):631-47. PMC: 4491675. DOI: 10.3390/cancers7020631. View

Moignier A, Gelover E, Wang D, Smith B, Flynn R, Kirk M . Improving Head and Neck Cancer Treatments Using Dynamic Collimation in Spot Scanning Proton Therapy. Int J Part Ther. 2019; 2(4):544-554. PMC: 6871640. DOI: 10.14338/IJPT-15-00026.1. View

Smith B, Hyer D, Hill P, Culberson W . Secondary Neutron Dose From a Dynamic Collimation System During Intracranial Pencil Beam Scanning Proton Therapy: A Monte Carlo Investigation. Int J Radiat Oncol Biol Phys. 2018; 103(1):241-250. DOI: 10.1016/j.ijrobp.2018.08.012. View

Miften M, Olch A, Mihailidis D, Moran J, Pawlicki T, Molineu A . Tolerance limits and methodologies for IMRT measurement-based verification QA: Recommendations of AAPM Task Group No. 218. Med Phys. 2018; 45(4):e53-e83. DOI: 10.1002/mp.12810. View

Hyer D, Hill P, Wang D, Smith B, Flynn R . Effects of spot size and spot spacing on lateral penumbra reduction when using a dynamic collimation system for spot scanning proton therapy. Phys Med Biol. 2014; 59(22):N187-96. DOI: 10.1088/0031-9155/59/22/N187. View

Magro G, Fassi M, Mirandola A, Rossi E, Molinelli S, Russo S . Dosimetric validation of a GPU-based dose engine for a fast in silico patient-specific quality assurance program in light ion beam therapy. Med Phys. 2022; 49(12):7802-7814. DOI: 10.1002/mp.16002. View

10.

Bennett L, Hyer D, Erhart K, Nelson N, Culberson W, Smith B . PETRA: A pencil beam trimming algorithm for analytical proton therapy dose calculations with the dynamic collimation system. Med Phys. 2023; 50(11):7263-7280. PMC: 10751389. DOI: 10.1002/mp.16559. View

11.

Smith B, Hyer D, Flynn R, Hill P, Culberson W . Trimmer sequencing time minimization during dynamically collimated proton therapy using a colony of cooperating agents. Phys Med Biol. 2019; 64(20):205025. PMC: 6995666. DOI: 10.1088/1361-6560/ab416d. View

12.

Lin L, Kang M, Solberg T, Mertens T, Baeumer C, Ainsley C . Use of a novel two-dimensional ionization chamber array for pencil beam scanning proton therapy beam quality assurance. J Appl Clin Med Phys. 2015; 16(3):5323. PMC: 5690130. DOI: 10.1120/jacmp.v16i3.5323. View

13.

Paddick I, Lippitz B . A simple dose gradient measurement tool to complement the conformity index. J Neurosurg. 2006; 105 Suppl:194-201. DOI: 10.3171/sup.2006.105.7.194. View

14.

Arjomandy B, Sahoo N, Ciangaru G, Zhu R, Song X, Gillin M . Verification of patient-specific dose distributions in proton therapy using a commercial two-dimensional ion chamber array. Med Phys. 2010; 37(11):5831-7. DOI: 10.1118/1.3505011. View

15.

Chang C, Poole K, Teran A, Luckman S, Mah D . Three-dimensional gamma criterion for patient-specific quality assurance of spot scanning proton beams. J Appl Clin Med Phys. 2015; 16(5):381–388. PMC: 5690160. DOI: 10.1120/jacmp.v16i5.5683. View

16.

Smith B, Gelover E, Moignier A, Wang D, Flynn R, Lin L . Technical Note: A treatment plan comparison between dynamic collimation and a fixed aperture during spot scanning proton therapy for brain treatment. Med Phys. 2016; 43(8):4693. PMC: 5360163. DOI: 10.1118/1.4955117. View

17.

Morales D, Shan J, Liu W, Augustine K, Bues M, Davis M . Automation of routine elements for spot-scanning proton patient-specific quality assurance. Med Phys. 2018; 46(1):5-14. PMC: 6322942. DOI: 10.1002/mp.13246. View

18.

Zhang X, Li Y, Pan X, Xiaoqiang L, Mohan R, Komaki R . Intensity-modulated proton therapy reduces the dose to normal tissue compared with intensity-modulated radiation therapy or passive scattering proton therapy and enables individualized radical radiotherapy for extensive stage IIIB non-small-cell.... Int J Radiat Oncol Biol Phys. 2009; 77(2):357-66. PMC: 2868090. DOI: 10.1016/j.ijrobp.2009.04.028. View

19.

Moignier A, Gelover E, Wang D, Smith B, Flynn R, Kirk M . Theoretical Benefits of Dynamic Collimation in Pencil Beam Scanning Proton Therapy for Brain Tumors: Dosimetric and Radiobiological Metrics. Int J Radiat Oncol Biol Phys. 2015; 95(1):171-180. DOI: 10.1016/j.ijrobp.2015.08.030. View

20.

Mayo C, Martel M, Marks L, Flickinger J, Nam J, Kirkpatrick J . Radiation dose-volume effects of optic nerves and chiasm. Int J Radiat Oncol Biol Phys. 2010; 76(3 Suppl):S28-35. DOI: 10.1016/j.ijrobp.2009.07.1753. View