Abstract
Background: Specific radiation delivered to the tumor by stereotactic radiosurgery (SRS) has become widely used in the treatment of brain metastasis. This study aimed to compare radiation dosimetry and its parameters from SRS using three different modalities: Helical Tomotherapy (HT), Volumetric Modulated Arc Therapy (VMAT), and Cone-based Linac Radiosurgery (Cone-based). Methods: Patients who had experienced oligo-brain metastasis received SRS in our treatment center. Each contouring dataset was re-planned to create radiation dosimetry in all three treatment systems (HT, VMAT, and Cone-based). The parameters of conformity index (CI), homogeneity index (HI), CI50, and gradient index (CGI) were analyzed to compare the effects of the three techniques. Results: A total of 21 patients with 39 lesions were included in this study. For single lesion, Cone-based and VMAT revealed statistically identical CI, CI50, and CGI values, while exhibiting the poorest HI value. For multiple lesions, Cone-based provided the best CI50 and CGI values. VMAT displayed better CI50 and CGI values than HT. Moreover, VMAT exhibited the lowest BrainV5Gy value and displayed the shortest beam on time (BoT) calculation. Lastly, Decision Score analysis demonstrated better performance in VMAT when compared to the Cone-based approach. Conclusions: Our data indicated the dosimetric comparison between three radiation techniques for single and multiple lesions. The Cone-based technique revealed the poorest HI value. On the other hand, VMAT provided the best estimated BoT value. Moreover, we have reported on the feasibility of SRS using HT, which has been associated with well-tolerability and an acceptable level of radiation output.Trial registration: Thai Clinical Trials Registry (TCTR) ID No. TCTR20200803006Date of registration: 24 July 2020 (Retrospectively registered)URL: http://www.thaiclinicaltrials.org/show/TCTR20200803006
Stereotactic Radiosurgery for Limited Brain Metastasis using Three Different Techniques; Helical Tomotherapy, Volumetric Modulated Arc Therapy, and Cone-Based Linac Radiosurgery.
