Commissioning of the world's first compact pencil-beam scanning proton therapy system.

Rajesh Pidikiti,Hsinshun Terry Wu,Lane R Rosen,Bijal C Patel,Narayan Sahoo,Joseph Syh,Joseph P Dugas,Matthew R Maynard

doi:10.1002/acm2.12225

Abstract

This paper summarizes clinical commissioning of the world's first commercial, clinically utilized installation of a compact, image‐guided, pencil‐beam scanning, intensity‐modulated proton therapy system, the IBA Proteus® ONE, at the Willis‐Knighton Cancer Center (WKCC) in Shreveport, LA. The Proteus® ONE is a single‐room, compact‐gantry system employing a cyclotron‐generated proton beam with image guidance via cone‐beam CT as well as stereoscopic orthogonal and oblique planar kV imaging. Coupling 220° of gantry rotation with a 6D robotic couch capable of in plane patient rotations of over 180° degrees allows for 360° of treatment access. Along with general machine characterization, system commissioning required: (a) characterization and calibration of the proton beam, (b) treatment planning system commissioning including CT‐to‐density curve determination, (c) image guidance system commissioning, and (d) safety verification (interlocks and radiation survey). System readiness for patient treatment was validated by irradiating calibration TLDs as well as prostate, head, and lung phantoms from the Imaging and Radiation Oncology Core (IROC), Houston. These results confirmed safe and accurate machine functionality suitable for patient treatment. WKCC also successfully completed an on‐site dosimetry review by an independent team of IROC physicists that corroborated accurate Proteus® ONE dosimetry.

Highlights

Proton therapy facilities are traditionally large, both in physical size and in requisite staffing for effective operation, often making them prohibitively expensive for community or regional cancer centers
Along with general machine characterization, this paper describes the clinical commissioning of the IBA ProteusâONE undertaken to ensure both safe and accurate patient treatment
Normalized Pristine Bragg peaks measured in water using a Bragg Peak chamber with and without a range shifter (RS) in place

Summary

Introduction

Proton therapy facilities are traditionally large, both in physical size and in requisite staffing for effective operation, often making them prohibitively expensive for community or regional cancer centers. Traditional passive scattering and uniform scanning systems can contribute unwanted neutron dose, a byproduct of proton interaction with beam-shaping components, to healthy tissue. Recent advances in proton therapy technology are changing both of these traditional standards with movement toward pencil beam-scanning (PBS) systems and development of smaller and of less expensive single-room compact proton therapy systems. PBS systems offer both improved target dose conformity and reduced neutron dose as compared to uniform scanning systems because they are capable of 94 | wileyonlinelibrary.com/journal/jacmp. Scanning beam systems have been developed by Hitachi, IBA, and other companies.[1,2,3]. At the Willis-Knighton Cancer Center (WKCC) in Shreveport, LA, the world’s first commercial, compact, image-guided, pencilbeam scanning proton therapy system, the IBA ProteusâONE, has been installed and commissioned. Proton treatment planning at WKCC is performed using the RayStation treatment planning system (TPS) (RaySearch Laboratories, Stockholm, Sweden), while the oncology information system (OIS) used is MOSAIQ (IMPAC Medical Systems, Inc., Sunnyvale, CA, USA)

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