Process‐based quality management for clinical implementation of adaptive radiotherapy

Abstract

Purpose: Intensity-modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient-specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high-priority errors and appropriate risk-mitigation strategies for clinical implementation of intensity-modulated ART. Methods: An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity-modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG-100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG-100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical. Results: FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Fortythree of 127 failures were identified as potentially critical. Risk-mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel. Conclusions: Results of the FMEA-based risk assessment demonstrate that intensity-modulated ART introduces different (but not necessarily more) risks than standard IMRT and may be safely implemented with the proper mitigations.

Failure mode and effects analysis based risk profile assessment for stereotactic radiosurgery programs at three cancer centers in Brazil

“…Table III gives the total number of subprocesses, process steps, and potential failure modes for all three centers. The number of process steps found in this study (47-56) is comparable to those reported by Ford et al, who reported 62 process steps for their study, 4 Noel et al, who reported 52 process steps for their study, 5 and Masini et al, who reported 73 process steps for their study. 6 Although the results presented by Ford et al and Noel et al correspond to analyses performed for external beam treatment, the differences between their studies and the present study are not expected to be very different recognizing the subtle differences that exist among all these studies.…”

“…Failure modes with severity index S ≥ 7 represented 68% of the total failure modes/cause combination found for center III, 62% for center II, and 45% for center I. Similar results for detectability D ≥ 5 were found to be 7.6% (49/644) for center I, 5 found for center I, 9.3% (47/506) for center II, and 8.0% (55/689) for center III. The factors O and D both depend on the causes of failure, but D also depends additionally on the detection mechanisms existing at a radiotherapy center.…”

Quantitative evaluation of patient setup uncertainty of stereotactic radiotherapy with the frameless 6D ExacTrac system using statistical modeling

“…In contrast to the end‐to‐end test quality assurance procedures, this system identifies the contribution of the different components, and highlights particularly the components that have the largest uncertainties contributions which can be fixed or reduced in the specific clinical application. Furthermore, this approach may be useful in failure mode and effect analysis used by forthcoming AAPM Task Group‐100, 24 , 25 in which the procedure is broken into different processes and each process is divided into subprocesses where the failure modes and large uncertainty sources can be identified and quantified. Once a process or subprocess with frequent failure modes or large errors is identified, integrated quality control procedures can be implemented whereby more frequent checking on this particular process is performed to achieve accurate and safe operation.…”

FMEA of manual and automated methods for commissioning a radiotherapy treatment planning system

“…An FMEA for both the MTP and ACP was performed, compared, and evaluated for robustness. Our group has successfully employed this method of appraisal in the past . Using this approach, FMEA assesses each step of every automated TPS commissioning test as well as that of the current recommended tests in MPPG 5.a.…”