Background: Studies suggest that integrating robust planning and noncoplanar volumetric modulated arc therapy (VMAT) may be a useful strategy for maximizing the benefits of dose delivery while maintaining resilience to uncertainty; however, the robustness of target coverage and the dose‐sparing performance for organs at risk of techniques that combine dynamic trajectory irradiation and robust planning have not been fully investigated.Purpose: We aimed to evaluate the combination of biaxially rotational dynamic radiation therapy (BROAD‐RT) with robust planning to improve the dosimetric outcomes and robustness of head and neck cancer (HNC) radiation therapy.Methods: We retrospectively analyzed 10 patients with oropharyngeal and hypopharyngeal cancers who were treated with VMAT. Robust‐VMAT, Robust‐Non‐Coplanar‐VMAT (Robust‐NC‐VMAT), and Robust‐BROAD‐RT plans were generated using the RayStation treatment planning system, with patient setup uncertainties of 3–5 mm in each of the three axial directions (left–right, anterior–posterior, and superior–inferior) applied to the clinical target volume (CTV) during robust optimization. The prescribed doses were 70 and 56 Gy in 35 fractions for high‐ and low‐risk CTVs, respectively. Dosimetric parameters, including dose coverage for the CTVs and organ at risk (OAR) sparing, were compared between the plans. Robustness was evaluated using eight uncertainty scenarios, each generated by applying ± 1.7 mm translational shifts simultaneously along all three orthogonal axes (left–right, anterior–posterior, and superior–inferior), resulting in a combined vector displacement of approximately 3 mm.Results: The Robust‐BROAD‐RT plans significantly reduced the mean doses to the contralateral and ipsilateral parotid glands and the oral cavity by 8.17, 6.20, and 3.03 Gy, respectively, compared to the Robust‐VMAT plans (p < 0.001, p < 0.001, and p = 0.002, respectively). Similarly, the Robust‐BROAD‐RT plans achieved significantly lower doses to the parotid glands and the oral cavity compared to the Robust‐NC‐VMAT plans (p = 0.004, p = 0.014, and p = 0.014, respectively). No significant differences were observed in the target coverage indices (D98, D50), conformity index (CI), or homogeneity index (HI) among the three techniques. The worst‐case scenario analysis showed that the degree of deterioration in these target‐related parameters did not differ significantly among the Robust‐BROAD‐RT, Robust‐VMAT, and Robust‐NC‐VMAT plans.Conclusions: The Robust‐BROAD‐RT plan achieved a further reduction in doses to the parotid and oral cavities while maintaining robustness comparable to that of conventional Robust VMAT planning.

Objectives: Although hippocampal-sparing whole-brain irradiation (HS-WBI) offers potential neurocognitive benefits, it poses challenges in treatment planning. This study aimed to compare the dose distributions of biaxially rotational dynamic radiation therapy (BROAD-RT) with a novel O-ring-type linear accelerator (OXRAY) and conventional non-coplanar volumetric modulated arc therapy (VMAT) planning (Conv-VMAT) in HS-WBI treatment plans. Methods: This study included 10 patients with brain metastases from lung cancer at our institution. The hippocampus was contoured using gadolinium-based contrast-enhanced magnetic resonance imaging, and hippocampal-sparing regions were created using a 5 mm margin around the hippocampus. Two virtual plans (BROAD-RT and Conv-VMAT) with 30 Gy in 10 fractions were created to compare the dose distributions in the planning target volume (PTV), hippocampus, eyes, and lens. All plans were analyzed using a paired t-test. Results: The mean (standard deviation [SD]) hippocampus-Dmax, -Dmean, -D100%, and -V10 were 11.10 (0.61), 7.95 (0.20), 7.01 (0.19), and 0.42 (0.34) for BROAD-RT and 16.10 (0.57), 9.89 (0.75), 8.24 (0.34), and 39.05 (25.89) for Conv-VMAT, respectively. All hippocampal parameters were significantly better with BROAD-RT than with Conv-VMAT (p < 0.01). The PTV-D98, -D50, -D2, -V35, and -homogeneity index did not exhibit significant differences between BROAD-RT and Conv-VMAT. Although lens-Dmax was significantly better in BROAD-RT than in Conv-VMAT (p < 0.01), no significant differences were observed in the eye-Dmax and chiasm-Dmax between BROAD-RT and Conv-VMAT. The mean (SD) BROAD-RT beam delivery time was 313.60 (34.91) s. Conclusions: BROAD-RT improved hippocampal sparing with acceptable PTV coverage and PTV homogeneity in HS-WBI planning. In addition, BROAD-RT has a clinically acceptable treatment duration.

Accurate positioning remains a central challenge in head and neck radiotherapy because highly conformal dose distributions are delivered near multiple critical organs, and clinically relevant discrepancies may not be resolved by rigid image-guided correction alone. This narrative review synthesizes evidence on positioning management in head and neck radiotherapy, with particular emphasis on the transition from couch correction to action-oriented clinical decision-making. Peer-reviewed studies, guidelines, and key reviews published between January 2005 and April 2026 were identified using PubMed/MEDLINE and reference screening. Positioning uncertainty is often region-specific and dynamic, reflecting lower-neck and shoulder mismatch, mandibular variation, mask-fit deterioration, functional motion, and progressive anatomical changes during treatment. Thermoplastic immobilization, customized headrests, bite blocks, cone-beam computed tomography, six-degree-of-freedom correction, and adaptive workflows have improved reproducibility and verification; however, these approaches do not eliminate mismatches caused by non-rigid posture, immobilization failure, or evolving anatomy. In such situations, the key clinical task is to distinguish rigid setup deviations suitable for online correction from discrepancies requiring repositioning, re-immobilization, repeat simulation, or adaptive replanning. Emerging technologies, including artificial intelligence, dose-of-the-day estimation, corrected CBCT, synthetic CT, rapid replanning, and workflow-integrated decision support, may help close the gap between mismatch detection and intervention selection. Positioning management should therefore evolve from a correction-centered model to an action-oriented framework that links observed geometric or anatomical change to the most appropriate clinical response.

Introduction: Previous computed tomography (CT) energy‐saving studies have primarily focused on after‐hours shutdown or idle energy use in diagnostic CT. Radiotherapy simulation, however, includes preparation and immobilisation steps that may prolong daytime non‐acquisition periods. This study quantified daytime energy use in radiotherapy simulation CT and evaluated the contribution of power‐saving operation. Methods: In this prospective single‐centre study, electrical power consumption was directly measured using a three‐phase power logger during five baseline and five power‐saving weekdays (08:00–18:00). Power measurements were integrated with patient in‐room intervals and simulation procedure categories. Staff perceptions of workflow impact were assessed using an anonymous questionnaire, and carbon implications were estimated from the measured energy reduction. Results: Mean directly measured clinical‐hour energy consumption decreased from 38.7 to 36.5 kWh/day with power‐saving operation, a 5.8% reduction. Non‐acquisition time during patient presence varied markedly by procedure, from 56.5% for respiratory‐gated four‐dimensional CT to 97.1% for head‐and‐neck simulation. Power‐saving operation shifted daytime power use towards a lower‐power state, corresponding to an estimated reduction of 0.84–1.01 kg‐CO ₂ per clinical day across the emission‐factor sensitivity range. Twenty of 21 staff (95.2%) reported no impact on patient throughput. Conclusion: Power‐saving operation reduced daytime energy consumption without meaningful workflow disruption. Radiotherapy simulation CT has prolonged, procedure‐dependent idle periods arising from radiotherapy‐specific preparation workflows, highlighting a practical and previously undercharacterised opportunity for energy reduction.