Novel strategy with the automatic non-coplanar volumetric-modulated arc therapy for angiosarcoma of the scalp

Abstract

Background: Total scalp irradiation presents technical and dosimetric challenges. While reports suggest that HyperArc, a new stereotactic radiosurgery planning technique applied to non-coplanar volumetric-modulated arc therapy (VMAT) technique, is associated with high conformity and rapid dose fall-off, the performance of HyperArc for total scalp irradiation has not been explored. The current study aimed to compare the dosimetric performance of HyperArc plans with those of non-coplanar VMAT plans in angiosarcoma of the scalp. Methods: Ten patients with angiosarcoma of the scalp were included in this study. The performance of three different plans administered using TrueBeam Edge were compared: non-coplanar VMAT using flattening filter (FF) beams (VMAT-FF), HyperArc using FF beams (HyperArc-FF), and HyperArc using flattening filter free (FFF) beams (HyperArc-FFF). The dose distribution, dosimetric parameters, and dosimetric accuracy for each of these plans were evaluated. Results: The three plans showed no statistically significant differences in target volume coverage, conformity, and homogeneity. The HyperArc-FF and HyperArc-FFF plans provided significantly lower mean brain doses (12.63 ± 3.31 Gy and 12.71 ± 3.40 Gy) than did the VMAT-FF plans (17.11 ± 5.25 Gy). There were almost no differences in sparing the organs at risk between the HyperArc-FF and HyperArc-FFF plans. The HyperArc-FF and HyperArc-FFF plans provided a shorter beam-on time than did the VMAT-FF plan. The 3%/2 mm gamma test pass rates were above 95% for all three plans. Conclusions: Our results suggest that the HyperArc plan can be potentially used for radiation therapy of target regions with large and complicated shapes, such as the scalp, and that there are no advantages of using FFF beams.

Dosimetric Comparison of Helical Tomotherapy and HyperArc Treatment Plans for Angiosarcoma of the Scalp

“…Thus, it is important to identify the optimal MF in TSI that improves plan quality and reproducibility. For the HA planning, the result was similar to our previous findings on the mean dose to the brain, although there were small differences in the collimator angle and the priority of optimization (22). Furthermore, the BOT in the HT plan was approximately six times longer than that in the HA plan.…”

“…Previous studies have shown the usefulness of HT and HA planning in TSI (16)(17)(18)22). In the current study, we first ANTICANCER RESEARCH 43: 3079-3087 (2023)…”

“…Some researchers showed that the HA plan is dosimetrically superior to the conventional VMAT plan for the treatment of various head and neck cancers (20,21). Our previous study demonstrated the superiority of the HA plan to the noncoplanar VMAT plan with regard to dose distribution, OARs sparing, and treatment time for TSI in AS (22). However, previous studies have not explored the dosimetric comparison of HT and HA plans for TSI in AS.…”

Clinical implementation of HyperArc

“…These studies show that HyperArc can create similar plans dosimetrically compared to other SRS techniques, while CyberKnife and GammaKnife plans are better for very small lesions. In addition to brain lesions, other studies have also demonstrated HyperArc can be used to treat disease at the nasopharynx [17] or lesions at the scalp [18]. Despite the number of published articles on HyperArc, a technical note published by Popple and Snyder is the only source of information to provide details on HyperArc commissioning [19].…”

Automated Non-coplanar Volumetric Modulated Arc Therapy Planning for Maxillary Sinus Carcinoma

“…A number of investigators have reported that HA plans provided a higher conformity dose for the target and a lower radiation dose for surrounding tissues compared to VMAT plans for patients with brain metastases (14). Recently, HA has been applied to extracranial tumors, such as angiosarcoma of the scalp (15) and head and neck cancers (16,17). Its superior dose distribution could form a new treatment approach.…”