The Effect of Slice Thickness on Contours of Brain Metastases for Stereotactic Radiosurgery

• DOI: 10.1016/j.adro.2021.100708
• Publication Date: 2021-04-14T05:43:08Z
• Authors: Sara L. Thrower; Karine A. Al Feghali; Dershan Luo; Ian Paddick; Ping Hou; Tina Briere; Jing Li; Mary Frances McAleer; Susan L. McGovern; Kristina Demas Wo...; Debra Nana Yeboa; Kristy K. Brock; Caroline Chung
• Keywords: Medical physics. Medical radiology. Nuclear medicine; 03 medical and health sciences; 0302 clinical medicine; R895-920; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; Scientific Article; RC254-282

Stereotactic radiosurgery is a common treatment for brain metastases and is typically planned on magnetic resonance imaging (MRI). However, the MR acquisition parameters used for patient selection and treatment planning for stereotactic radiosurgery can vary within and across institutions. In this work, we investigate the effect of MRI slice thickness on the detection and contoured volume of metastatic lesions in the brain.A retrospective cohort of 28 images acquired with a slice thickness of 1 mm were resampled to simulate acquisitions at 2- and 3-mm slice thickness. A total of 102 metastases ranging from 0.0030 cc to 5.08 cc (75-percentile 0.36 cc) were contoured on the original images. All 3 sets of images were recontoured by experienced physicians.Of all the images detected and contoured on the 1 mm images, 3% of lesions were missed on the 2 mm images, and 13% were missed on the 3 mm images. One lesion that was identified on both the 2 mm and 3 mm images was determined to be a blood vessel on the 1 mm images. Additionally, the lesions were contoured 11% larger on the 2 mm and 43% larger on the 3 mm images.Using images with a slice thickness >1 mm effects detection and segmentation of brain lesions, which can have an important effect on patient management and treatment outcomes.