# SRS **URL:** https://forum.sgrt.org/c/srs/21.md [Latest](https://forum.sgrt.org/latest.md) · [Categories](https://forum.sgrt.org/categories.md) · [Tags](https://forum.sgrt.org/tags.md) --- ## [About the SRS category](https://forum.sgrt.org/t/about-the-srs-category/274)
**Author:** [@system](https://forum.sgrt.org/u/system)\ **Replies:** 0\ **Last updated:** [August 19, 2025, 8:25pm UTC](https://forum.sgrt.org/t/about-the-srs-category/274 "2025-08-19T20:25:47Z")
--- ## [SGRT and Hexapod 6DoF couch](https://forum.sgrt.org/t/sgrt-and-hexapod-6dof-couch/259)
**Author:** [@colin\_jennings](https://forum.sgrt.org/u/colin_jennings)\ **Replies:** 2\ **Last updated:** [July 17, 2025, 1:56pm UTC](https://forum.sgrt.org/t/sgrt-and-hexapod-6dof-couch/259 "2025-07-17T13:56:58Z")
We are expanding our use of SGRT to SRS (non-coplanar) and other head and neck which we also use the Elekta Hexapod 6 DoF couch and iGuide software. Has anyone got any experience of the challenges and benefits of using t… --- ## [Beam hold delay](https://forum.sgrt.org/t/beam-hold-delay/238)
**Author:** [@meral\_reyhan](https://forum.sgrt.org/u/meral_reyhan)\ **Replies:** 1\ **Last updated:** [September 4, 2024, 1:11pm UTC](https://forum.sgrt.org/t/beam-hold-delay/238 "2024-09-04T13:11:58Z")
We use beam gating with the default 1 mm tolerances for our SRS cases (Hyperarc style) and generally have issues when the gantry blocks 1 of the 3 AlignRT cameras. The beam will gate multiple times per arc when the camer… --- ## [Beam hold delay](https://forum.sgrt.org/t/beam-hold-delay/239)
**Author:** [@meral\_reyhan](https://forum.sgrt.org/u/meral_reyhan)\ **Replies:** 1\ **Last updated:** [September 4, 2024, 1:11pm UTC](https://forum.sgrt.org/t/beam-hold-delay/239 "2024-09-04T13:11:01Z")
We use beam gating with the default 1 mm tolerances for our SRS cases (Hyperarc style) and generally have issues when the gantry blocks 1 of the 3 AlignRT cameras. The beam will gate multiple times per arc when the camer… --- ## [RTD instability and SRS cube calibration](https://forum.sgrt.org/t/rtd-instability-and-srs-cube-calibration/237)
**Author:** [@colin\_jennings](https://forum.sgrt.org/u/colin_jennings)\ **Replies:** 1\ **Last updated:** [August 14, 2024, 8:36am UTC](https://forum.sgrt.org/t/rtd-instability-and-srs-cube-calibration/237 "2024-08-14T08:36:42Z")
Hi, We use 2 linacs for intracranial SRS. Both have AlignRT and 6-DoF couch (Hexapod). On one of these linacs we have the VisionRT SRS cube calibration but not on the other. Testing AlignRT with a phantom and couch rota… --- ## [RTD instability and SRS cube calibration](https://forum.sgrt.org/t/rtd-instability-and-srs-cube-calibration/236)
**Author:** [@colin\_jennings](https://forum.sgrt.org/u/colin_jennings)\ **Replies:** 1\ **Last updated:** [July 12, 2024, 11:46am UTC](https://forum.sgrt.org/t/rtd-instability-and-srs-cube-calibration/236 "2024-07-12T11:46:07Z")
Hi, We use 2 linacs for intracranial SRS. Both have AlignRT and 6-DoF couch (Hexapod). On one of these linacs we have the VisionRT SRS cube calibration but not on the other. Testing AlignRT with a phantom and couch rota… --- ## [Deviation During Couch Kicks](https://forum.sgrt.org/t/deviation-during-couch-kicks/137)
**Author:** [@jose\_carlos\_pichardo](https://forum.sgrt.org/u/jose_carlos_pichardo)\ **Replies:** 7\ **Last updated:** [November 30, 2020, 6:49am UTC](https://forum.sgrt.org/t/deviation-during-couch-kicks/137 "2020-11-30T06:49:54Z")
I have two questions: (1) Is everyone simulating brain SRTs with chin neutral or down? If not, why not? (2) What is your process when RTDs exceed 1 mm after the couch has been rotated, particularly to 90 or 270? To exc… --- ## [Camera Install Practices for SRS](https://forum.sgrt.org/t/camera-install-practices-for-srs/135)
**Author:** [@dustin\_jacqmin](https://forum.sgrt.org/u/dustin_jacqmin)\ **Replies:** 1\ **Last updated:** [February 19, 2020, 1:09pm UTC](https://forum.sgrt.org/t/camera-install-practices-for-srs/135 "2020-02-19T13:09:44Z")
When my vendor of SGRT technology installs their surface imaging cameras, they configure the cameras in a number of ways to optimize camera performance. This process is repeated annually during preventative maintenance. … --- ## [SRS Simulation Best Practices](https://forum.sgrt.org/t/srs-simulation-best-practices/136)
**Author:** [@dustin\_jacqmin](https://forum.sgrt.org/u/dustin_jacqmin)\ **Replies:** 1\ **Last updated:** [February 16, 2020, 3:22pm UTC](https://forum.sgrt.org/t/srs-simulation-best-practices/136 "2020-02-16T15:22:48Z")
At my institution, we experience RTD drift at couch angles approaching 90 and 270 degrees, as discussed in some of the other Topic’s in this form. We are working on controlling our processes more tightly to reduce this i… --- ## [Deviation During Couch Kicks](https://forum.sgrt.org/t/deviation-during-couch-kicks/132)
**Author:** [@kileigh\_peturis](https://forum.sgrt.org/u/kileigh_peturis)\ **Replies:** 5\ **Last updated:** [July 22, 2019, 2:27pm UTC](https://forum.sgrt.org/t/deviation-during-couch-kicks/132 "2019-07-22T14:27:08Z")
Hello, We are using OSMS during SRS treatments and we’ve set the tolerance at 1 mm and 0.5 degrees to indicate if we should pause and re-image. We’ve been using the system for about a year now, and pretty consistently w… --- ## [CBCT DICOM REF IMAGE vs TX DICOM REF IMAGE](https://forum.sgrt.org/t/cbct-dicom-ref-image-vs-tx-dicom-ref-image/134)
**Author:** [@sheila\_cioffa](https://forum.sgrt.org/u/sheila_cioffa)\ **Replies:** 3\ **Last updated:** [March 6, 2019, 2:44pm UTC](https://forum.sgrt.org/t/cbct-dicom-ref-image-vs-tx-dicom-ref-image/134 "2019-03-06T14:44:19Z")
When treating Brain cases (SRT in our center), if the lesion is located far from mid-brain, we center the patient prior to the CBCT so as to acquire the full cranium. When using VisionRT, you want to adjust based on your… --- ## [Open Mask](https://forum.sgrt.org/t/open-mask/127)
**Author:** [@serpil\_wilson\_ms\_dabr](https://forum.sgrt.org/u/serpil_wilson_ms_dabr)\ **Replies:** 4\ **Last updated:** [November 15, 2018, 12:54pm UTC](https://forum.sgrt.org/t/open-mask/127 "2018-11-15T12:54:46Z")
What is everyone’s opinion on different open masks? Also does anyone have an opinion on the bite blocks built in open masks? --- ## [RTD instability](https://forum.sgrt.org/t/rtd-instability/133)
**Author:** [@jose\_carlos\_pichardo](https://forum.sgrt.org/u/jose_carlos_pichardo)\ **Replies:** 1\ **Last updated:** [November 1, 2018, 9:01pm UTC](https://forum.sgrt.org/t/rtd-instability/133 "2018-11-01T21:01:09Z")
We have recently purchased the Vision RT system with the head adjuster at our center. I am in the process of commissioning the system and I am using a Styrofoam head with a thermoplastic mask into which I have inserted t… --- ## [ROI and couch kicks with SRS](https://forum.sgrt.org/t/roi-and-couch-kicks-with-srs/131)
**Author:** [@whitney\_dore](https://forum.sgrt.org/u/whitney_dore)\ **Replies:** 1\ **Last updated:** [August 9, 2018, 12:08pm UTC](https://forum.sgrt.org/t/roi-and-couch-kicks-with-srs/131 "2018-08-09T12:08:40Z")
Hello everyone! Just curious if anyone has experienced a problem with the ROI rotating incorrectly on the patient when capturing a reference image at the couch kick? We recently started a SRS patient, once kicking the … --- ## [Covering the eyes for SGRT-SRS](https://forum.sgrt.org/t/covering-the-eyes-for-sgrt-srs/130)
**Author:** [@dustin\_jacqmin](https://forum.sgrt.org/u/dustin_jacqmin)\ **Replies:** 2\ **Last updated:** [February 28, 2018, 10:08pm UTC](https://forum.sgrt.org/t/covering-the-eyes-for-sgrt-srs/130 "2018-02-28T22:08:45Z")
Hey all, My institution is in the process of implementing frameless SRS using VisionRT and open-faced masks. We are piloting the system one some hypo-fractionated brain patients. One early issue we’ve identified is that… --- ## [CBCT-SRS cones](https://forum.sgrt.org/t/cbct-srs-cones/129)
**Author:** [@soddiraju](https://forum.sgrt.org/u/soddiraju)\ **Replies:** 1\ **Last updated:** [February 5, 2018, 1:18pm UTC](https://forum.sgrt.org/t/cbct-srs-cones/129 "2018-02-05T13:18:06Z")
Can anyone tell how to monitor patients during CBCT for SRS cones. Since ROI is blocked by the imaging arms and cones, AlignRT is giving us a message saying that patient movement outside tolerance for more than 0 seconds… --- ## [OpenMask-SRS](https://forum.sgrt.org/t/openmask-srs/128)
**Author:** [@serpil\_wilson\_ms\_dabr](https://forum.sgrt.org/u/serpil_wilson_ms_dabr)\ **Replies:** 4\ **Last updated:** [October 12, 2017, 8:30am UTC](https://forum.sgrt.org/t/openmask-srs/128 "2017-10-12T08:30:37Z")
We do use open mask without a bite block for our SRS cases. There are some open masks with built in bite blocks in the market. Does anyone have experience with them? or any opinion? My personal opinion: AlignRT works gr…