ASTRO 2020: Use of 3D Optical Scanner to Enhance Radiotherapy for Skin Cancer
Posted: Friday, November 6, 2020
Use of a high-resolution, three-dimensional (3D) optical surface scanner may potentially allow better target delineation and improved workflow in planning radiation treatment of lesions in patients with non-melanoma skin cancer, results of a small pilot study indicate. Timothy Hanna, MD, MSc, PhD, of Queen’s Cancer Research Institute, Kingston, Ontario, and colleagues presented their work in a poster during the virtual edition of the 2020 Annual Meeting of the American Society for Radiation Oncology (ASTRO; Abstract 2724). “To our knowledge, this is the first report of the use of an optical scanner to perform virtual clinical markups,” they reported.
Usually, a radiation oncologist identifies the tumor through physical assessment and marks the margins for radiotherapy. All five patients in the pilot study had basal cell carcinoma or squamous cell carcinoma. “Patients had an initial scan with an Artec 3D scanner, and a virtual image was created on 3D Slicer, an open platform. An experienced radiation oncologist then inked a gross tumor volume and a treatment margin on the patient’s face, representing the field edge for orthovoltage radiotherapy and the clinical target volume for electron radiotherapy,” the investigators explained. Later, they obtained a second optical scan in which the clinical markup was visible, and the image was again created on 3D Slicer.
A total of 2 weeks or more after acquiring the surface scans, the same physician performed a virtual markup by delineating the gross tumor volume on the unmarked 3D surface scan. “The virtual markup on the first optical scan was then fused to the scanned clinical markup on the second optical scan on 3D Slicer,” the investigators described.
“The maximum difference between the virtual markup gross tumor volume and the clinical markup was 5.34 + 2.18 mm, [whereas] the mean difference was 2.28 ± 1.35 mm,” they stated. Going forward, they suggested, optimizing image color accuracy, improving scanning technique, and developing tools “to augment image clinical features” could be goals of further research.
Disclosure: The study authors reported no conflicts of interest.