Applications of machine and deep learning to patient-specific IMRT/VMAT quality assurance

Abstract

In order to deliver accurate and safe treatment to cancer patients in radiation therapy using advanced techniques such as intensity modulated radiation therapy (IMRT) and volumetric-arc radiation therapy (VMAT), patient specific quality assurance (QA) should be performed before treatment. IMRT/VMAT dose measurements in a phantom using various devices have been clinically adopted as standard method for QA. This approach allows the verification of the accuracy of the dose calculation, data transfer, and the delivery system. However, patient-specific QA procedures are expensive and require significant time and effort by the physicists. Over the past 5 years, machine learning (ML) and deep learning (DL) algorithms for predictions of IMRT/VMAT QA outcome have been investigated. Various ML and DL models have shown promising prediction accuracy and a high potential as time-efficient virtual QA tool. In this paper, we review the ML and DL based models that were developed for patient specific IMRT and VMAT QA outcome predictions from algorithmic and clinical applicability perspectives. We focus on comparing the algorithms, the dataset sizes, the input parameters and features, the QA outcome prediction approaches, the validation, the performance, the clinical applicability, and the potential clinical impact. In addition, we discuss the present challenges as well as the future directions in the implementation of these models. To the best of our knowledge, this is the first review on the application of ML and DL based models in IMRT/VMAT QA predictions.

Keywords: IMRT quality assurance; VMAT quality assurance; deep learning; gamma passing rate prediction; machine learning; patient-specific QA; radiation therapy.

FIGURE 1

Yearly published articles related to intensity modulated radiation therapy and volumetric‐arc radiation therapy quality assurance outcome predictions using machine learning and deep learning algorithms, until March, 2021 (PubMed)

FIGURE 2

A typical flow diagram of patient‐specific intensity modulated radiation therapy/volumetric‐arc radiation therapy (IMRT/VMAT) quality assurance (QA). (Top) current clinically adopted QA based‐measurement approach, (Bottom) machine learning/deep learning (ML/DL)‐based approach for predicting the gamma passing rate results and detecting or identifying the types of QA errors for failing plans