Six workflows, one mask family —and the daily-imaging cadence each one runs on.

Setup-accuracy anchor: Mean 6D translational setup 0.32 / −1.09 / 2.24 mm; rotational < 0.4° on every axis (You 2024 · MVCT · n = 920 images)

Chain: Mask moulds to patient at 65 °C simulation, hardens as it cools, indexes onto the S-frame headrest baseplate. Daily image guidance corrects the residual setup error to within CBCT verification tolerance.

Setup-accuracy anchor: Intrafractional 3D drift plateau: 0.21 ± 0.26 mm at 0-2 min → 0.53 ± 0.31 mm at 10 min under mask fixation (Mangesius 2019 · 96 fractions · 453 ExacTrac measurements)

Chain: Full-face shell + SRS bite-block hard-locks head geometry. Beam-on delivery ceiling per fraction is set by the intrafractional-drift plateau at ~10 min. If the plan exceeds that, split into two mask-on sessions or upgrade to a 3-point cushion + mask + bite-block configuration.

Setup-accuracy anchor: Systematic translational setup error < 1 mm across the multi-centre European MR-Linac cohort (Cuccia 2021 · Radiation Oncology · systematic review)

Chain: Polymer sheet is MR-safe by default; the non-ferromagnetic fastener set closes the loop for MR-Linac + MR-sim. Same indexed pitch on the MR-sim and MR-Linac; the CT-derived isocentre transfers without per-room recalibration.

Setup-accuracy anchor: Sized for paediatric anatomy; same low-temperature-activation moulding as the adult SRS configuration

Chain: The 65 °C activation temperature is well below the paediatric skin burn threshold, which is what makes the perforated-polymer moulding step usable on children. Alternative rigid stereotactic frames are not paediatric-appropriate under general anaesthesia; the mask is.

Setup-accuracy anchor: Best-in-class daily-CBCT alignment within 2 mm across 158 CBCT / 19 patients on the custom-headrest + mouth-bite mask configuration: 99.4 % AP / 100 % SI / 98.7 % RL (Mail 2024 · J Biol Methods)

Chain: Body-shell restrains trunk motion across the fraction series; pairs with the thermoplastic head mask (RT-001 or RT-002) for the H&N + nodal treatment plans that need dual immobilisation. Indexed onto the thorax baseplate from the Patient Positioning Solutions family.

Setup-accuracy anchor: MD Anderson H&N SRT re-irradiation cohort: initial 3D vector 2.7 ± 1.4 mm corrected to 0.0 ± 0.3 mm axis-per-axis residual after robotic-couch adjustment (Wang 2016 · JACMP · 21 patients / 105 sessions)

Chain: The three-point (custom cushion + thermoplastic mask + SRS bite-block) configuration is the concrete answer for H&N re-irradiation where the standard configuration cannot deliver the < 2 mm PTV margin the CTV would otherwise leave for organs at risk.