MSS11 Presentation Time: 4:35 PM

Purpose

The use of artificial intelligence (AI) in radiation therapy has been increased in the last years. The aim of this work is to investigate the use of AI in contouring during the interstitial HDR brachytherapy of the primary and secondary liver tumors.

Materials and Methods

25 patients with 37 hepatic lesions of histologically confirmed primary and secondary liver tumors. The Liver tumors were treated by single fractioninterstitial HDR brachytherapy. The Brachytherapy Applicators were implanted into the tumor regions under CT guidance. Subsequently, a Planning CT with contrast medium and a slice thickness of 1.25 mm was performed. Retrospectively, the organs at risk (OAR) were assessed by an experienced Radiation Oncologist, as well as using AI by the autocontouring software Limbus Contour v.1.5.0. Here the calculations were performed once by the CPU (Central Processing Unit) and once by the GPU (Graphics Processing Unit). A PC with the Intel® Xeon® E5-2620V3 processor (CPU), 2.40 GHz, was used, as well as a graphics card (GPU) NVIDIA Quadro K620, 2GB GDDR3. The following organs at risk contoured: Liver, kidneys, stomach, intestine, heart, esophagus, and lungs. The time required for time required to contour the organs at risk was compared.

Results

The types of Tumor were illestrated in Figure 1. For the experienced radiation oncologist, the mean±standard deviation was 17.08±0.61 minutes. The software required a mean of 3.71±0.45 minutes for the CPU calculations. When using the GPU, the calculation time was only 2.24±0.23 minutes. The contouring times differed significantly (p <0.001). In 21 metastases, the contouring of Stomach was required, in 26 metastases required contouring of the right kidney, and in 33 metastases the contouring of intestine was required.

Conclusions

The application of artificial intelligence to interstitial HDR brachytherapy of the liver brachytherapy can shorten the treatment by about 15 minutes on average. This reduces the unpleasant lying time with applicators for the patient.