The new SRS/FSRT technique HyperArc for benign brain lesions: a dosimetric analysis

Area of Science:

• Radiation Oncology
• Neurosurgery
• Medical Physics

Background:

• Benign brain lesions require precise radiotherapy for effective treatment.
• Conventional fractionated stereotactic radiotherapy (FSRT) techniques may have limitations in dose distribution.
• Evaluating advanced technologies like HyperArc (HA) is crucial for optimizing treatment outcomes.

Purpose of the Study:

• To assess the dosimetric benefits of HyperArc (HA) fractionated stereotactic radiotherapy (FSRT) for benign brain lesions.
• To compare HA treatment planning with different optimization algorithms against coplanar RapidArc (RA) and cone-based CyberKnife (CK).

Main Methods:

• Retrospective analysis of 16 patients with single, deep-seated benign brain lesions treated with CyberKnife (CK).
• Generated treatment plans using HA with SRS NTO and ALDO algorithms, and coplanar RapidArc (RA).
• Compared dosimetric outcomes between homogeneous (HA-SRS NTO, RA) and inhomogeneous (HA-ALDO, CK) delivery groups.

Main Results:

• HA-SRS NTO plans showed significantly lower brain V5, V12, V24, and mean brainstem dose compared to coplanar RA.
• HA-SRS NTO demonstrated superior conformity index, reduced dose spillage, and better gradient radius than RA.
• HA-ALDO plans achieved better PTV coverage and improved organ-at-risk sparing compared to cone-based CK.

Conclusions:

• HyperArc (HA) provides excellent dosimetric distribution for treating benign brain lesions.
• HA, particularly with the SRS NTO algorithm, offers significant advantages over coplanar RapidArc for homogeneous delivery.
• HA-ALDO shows superiority over cone-based CyberKnife for inhomogeneous delivery, establishing HA as an attractive FSRT technique.