Multicentre quality assurance of intensity‐modulated radiation therapy plans: A precursor to clinical trials

Abstract

A multicentre planning study comparing intensity-modulated radiation therapy (IMRT) plans for the treatment of a head and neck cancer has been carried out. Three Australian radiotherapy centres, each with a different planning system, were supplied a fully contoured CT dataset and requested to generate an IMRT plan in accordance with the requirements of an IMRT-based radiation therapy oncology group clinical trial. Plan analysis was carried out using software developed specifically for reviewing multicentre clinical trial data. Two out of the three plans failed to meet the prescription requirements with one misinterpreting the prescription and the third failed to meet one of the constraints. Only one plan achieved all of the dose objectives for the critical structures and normal tissues. Although each centre used very similar planning parameters and beam arrangements the resulting plans were quite different. The subjective interpretation and application of the prescription and planning objectives emphasize one of the many difficulties in carrying out multicentre IMRT planning studies. The treatment prescription protocol in a clinical trial must be both lucid and unequivocally stated to avoid misinterpretation. Australian radiotherapy centres must show that they can produce a quality IMRT plan and that they can adhere to protocols for IMRT planning before using it in a clinical trial.

Data-Driven Approach to Generating Achievable Dose–Volume Histogram Objectives in Intensity-Modulated Radiotherapy Planning

“…In contrast, the CPs were planned by 5 dosimetrists. As mentioned in the ''Introduction,'' there is little doubt that current IMRT planning is associated with a high degree of heterogeneity among institutions and even within the same institutions (3,4). Our method thus provides a consistent and systematic method for generating DVH objectives in IMRT planning.…”

“…It has been shown that IMRT plan quality varies among planners by level of experience (3). Even for the same patient, the planning results are often highly heterogeneous (4). Consequently, IMRT plan quality heavily relies on the personal experience of planners and the time they can allocate to a specific plan.…”

Evaluating inter-campus plan consistency using a knowledge based planning model

“…Moore et al[19] has found, using NTCP analysis, that KBP can identify suboptimal plans in large interinstitutional trials even when the trials included rigorous segmentation guidelines and dosimetric OAR constraints. Such variability has been attributed to differences in planning systems, linac capabilities, and institutional experience with the treatment technique[20, 21] but not, to date, individual planner characteristics such as education, certification status, or years of experience[10, 22]. In this study, we were interested in determining whether KBP could identify systematic differences in planning approaches between campuses of a single institution, where again, the same planning system, planning guidelines, and plan evaluation criteria were used.…”

A DVH-guided IMRT optimization algorithm for automatic treatment planning and adaptive radiotherapy replanning

“…38. Problems (1) and (2) illustrate the general form of the voxel-based and the organ-based optimization models, respectively,…”

“…Plan quality is subjective and highly dependent on the institution and the planners' skills and experiences. [1][2][3] Automatic treatment planning has been introduced to facilitate this procedure. Two general techniques have been followed in automatic treatment planning.…”