Abstract
Objectives: Ultrasound-guided high-intensity focused ultrasound (USgHIFU) remains a highly operator-dependent procedure, and the lack of standardized treatment strategies continues to limit procedural consistency across centers. This study presents the “3D-Grid Navigation Protocol,” a structured procedural framework designed to standardize treatment delivery and improve reproducibility. Our observations suggest that adherence to a systematic point-by-point irradiation strategy and 3D mapping may help reduce incomplete ablation patterns. Imaging findings indicate that this protocol can be consistently implemented in clinical practice. Methods: The protocol integrates a structured mapping logic based on 10-mm treatment-plane intervals and adaptive focal spacing, generally within approximately 5–10 mm according to lesion characteristics and real-time ultrasound response. Key strategies include: (1) Centrifugal Expansion, beginning treatment at the central plane and progressing toward the periphery; (2) Layered Treatment, prioritizing the deeper first layer before adaptively treating the more superficial second layer; and (3) Booster Sonication, providing additional cumulative treatment at selected central and peripheral coordinates according to lesion type and real-time tissue response. A structured treatment mapping chart was utilized to record coordinates in real-time, aiming to ensure complete coverage and minimize the risk of technical omissions. Results: Between 2010 and 2025, this protocol was applied consecutively in 2992 patients, including the initial series of 1807 patients previously reported in 2019 [2]. This extensive clinical experience provided the practical foundation for the development and refinement of the standardized 3D-grid navigation framework described in the present study.Our observations suggest that adherence to a systematic point-by-point irradiation strategy and structured 3D mapping may help reduce incomplete deep-core necrosis despite apparent full sonication.Imaging-based observations using multi-modal imaging indicate that the integration of precise MRI–ultrasound alignment and adaptive power control (300–400 W) may contribute to consistent thermal necrosis, supporting the practical reproducibility of the protocol even in heterogeneous tissue environments. Conclusions: The 3D-Grid Navigation Protocol presents a structured approach that may help reduce clinical variability associated with operator-dependent techniques. By supporting a more standardized treatment framework, this protocol may serve as a practical reference for operators seeking consistent and safe outcomes in the treatment of uterine fibroids and adenomyosis.