The RPC Proton Therapy Approval Process

Paige Summers, MS

This project is supported by the Federal Share of program income earned by Massachusetts General

Hospital on C06 CA059267, Proton Therapy Research and Treatment Center and by grants CA10953 and

CA81647 (NCI, DHHS)..

RPC’s Proton Involvement

•Asked by the NCI to help ensure cooperative groups that proton centers are delivering clinically comparable and consistent dose

•Proton visits funded in part by NCI/MGH shared funds

• 10 clinical sites (8 in trials)

• Forecast 18 new sites

• NCI/MGH funds extended until 12/31/12

Proton Approval Steps

•Proton facility questionnaire

•Annual monitoring of beam calibrations by the RPC

•Ability to electronically transfer treatment plans

•Successful irradiation of RPC’s baseline proton phantoms

•Successful completion of on-site dosimetry review visit

Facility Questionnaire

•AAPM Proton Advisory group aids RPC in updating proton facility questionnaire

•Questions covered: • Experiences in the clinic• Dose calibration & verification• Proton beam production & delivery• Treatment Planning• Immobilization• Patient Alignment• QA

Annual Beam Audit – RPC TLD

•Ten proton centers monitored

•In process of switching from TLD to OSLD to monitor beam output annually

•Plan to use dosimeters for depth dose measurements

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Electronic Data Transfer

•Institutions must be able to submit treatment plans electronically to the ITC

•Data used for RPC phantom audits, study group credentialing

RPC Proton Phantom Program

•Baseline phantoms:• Scattered, uniform scanning:

prostate & spine• Spot scanning: Lung, head,

prostate

RPC Proton Site Visits

•NCI/RPC recommend institutions only visited after center has been routinely treating patients for minimum of 6 months with no fewer than 3 disease sites

•Different delivery modalities have separate audit requirements – must each be reviewed

•Prioritization dependent on inst. initiative, membership in cooperative groups, readiness

•Dosimetric and imaging quality evaluation criteria being developed

RPC Proton Site Visits

•Typical review components:

•Dosimetry equipment calibration

•CT scanner, CTN/RSP conversion

•Patient immobilization

•Treatment planning procedures

•QA documentation

RPC Proton Site Visits

•Typical site visit measurements

• Beam calibration comparison – RPC/Inst

• CAX lateral and depth dose profiles for reference and patient fields

• Scanning beam – less fields tested, more profiles obtained

• X-ray system measurements

• TLD measurements

RPC Proton Site Visits

•After visits, RPC generates comprehensive site visit report – sent to institution with recommendations

•If measurements and procedures pass criteria, approval letter sent to institution, ITC, RTOG, & QARC

Questions?

http://www.mdanderson.org/patient-and-cancer-information/proton-therapy-center/meet-our-survivors/index.html

RPC Proton Phantom Program

•Goals:•Implement use of OSLD

for phantom audits•Modify existing

phantoms for proton use•Liver: multiple targets•Lung: motion•Prostate: proton

equivalent •Head: H&N target

Proton liver insert – blue water replaces

polystyrene

RPC’s Proton Goals

•Proton facility questionnaire

•Have existing facilities update

•Set up facility questionnaire online

•OSLD for phantom audits

•Adapt site visit procedures for new proton technologies

•Scanning beams, MevIon systems

Most measurements at mid-SOBP ± 2 cm

RPC Proton TLD Program

Brain Phantom Selected Phantom Lab “Alderson” phantom

Materials fall on CT#-RLSP curve Contains realistic bony anatomy Inserts with target and dosimetry will be constructed

MR image to define CTVMR image fused with CT for prescription and dose calc

Lung Phantom