Use of AlignRT System During Stereotactic Radiosurgery

July 15, 2026 updated by: Institute of Oncology Ljubljana
This prospective study evaluated whether the AlignRT surface-guided radiotherapy system improves patient positioning accuracy during stereotactic radiosurgery (SRS) for brain metastases compared with standard manual positioning. Twenty adults scheduled for single-fraction SRS were positioned twice before treatment. Participants were first positioned using the standard manual method with delta couch shift and were then positioned automatically using the AlignRT system. After each positioning method, a partial cone-beam computed tomography (CBCT) scan was performed to measure residual setup deviations in three translational and three rotational directions. The primary objective was to compare the average setup deviations between the two positioning methods and determine whether AlignRT provided more accurate patient positioning. The additional positioning and imaging procedure prolonged the treatment visit by up to 15 minutes and involved a low additional imaging dose.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This was a prospective, single-group clinical study conducted at the Institute of Oncology Ljubljana. The study included adult patients with brain metastases who were scheduled to receive single-fraction stereotactic radiosurgery using the TrueBeam STx linear accelerator.

Each participant underwent two positioning procedures before treatment. Standard manual positioning was performed using the delta couch shift function, followed by partial CBCT verification. The participant was then positioned automatically using the AlignRT surface-guided radiotherapy system, followed by a second partial CBCT verification.

Residual positioning deviations were recorded in three translational directions (vertical, longitudinal, and lateral) and three rotational directions (rotation, pitch, and roll). The average deviations obtained after manual positioning were compared with those obtained after AlignRT-guided positioning. Additional analyses considered participant age and sex. Positioning data were obtained from the ARIA information system and analyzed using Microsoft Excel and IBM SPSS.

A total of 20 participants completed the study. No additional follow-up was required after completion of the positioning measurements.

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Slovenia
      • Ljubljana, Slovenia, 1000
        • Institute of Oncology Ljubljana

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 years or older
  • Patients with brain metastases eligible for single-fraction stereotactic radiosurgery
  • Treatment performed using the TrueBeam STx linear accelerator
  • Able and willing to provide written informed consent.

Exclusion Criteria:

  • Patients younger than 18 years
  • Patients receiving fractionated stereotactic radiotherapy
  • Treatment performed using a linear accelerator other than TrueBeam STx.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Manual and AlignRT-Guided Positioning
Participants underwent standard manual positioning followed by automatic positioning using the AlignRT system before stereotactic radiosurgery. A partial cone-beam computed tomography scan was performed after each positioning method to measure residual translational and rotational setup deviations.
Other: Manual Patient Positioning
Participants were manually positioned from the initial setup position to the treatment isocenter using the delta couch shift function. A partial cone-beam computed tomography scan was then performed to measure residual setup deviations in three translational and three rotational directions.
Other: AlignRT-Guided Patient Positioning
Participants were automatically positioned at the treatment isocenter using the AlignRT surface-guided radiotherapy system. A partial cone-beam computed tomography scan was then performed to measure residual setup deviations in three translational and three rotational directions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Residual Translational Setup Deviations After Manual and AlignRT-Guided Positioning
Time Frame: Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Residual setup deviations measured by partial cone-beam computed tomography in the vertical, longitudinal, and lateral directions, expressed in centimeters. Mean deviations were compared between manual positioning and AlignRT-guided positioning within the same participants.
Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Residual Rotational Setup Deviations After Manual and AlignRT-Guided Positioning
Time Frame: Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Residual setup deviations measured by partial cone-beam computed tomography for rotation, pitch, and roll, expressed in degrees. Mean deviations were compared between manual positioning and AlignRT-guided positioning within the same participants.
Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in Absolute Translational Setup Deviations Between AlignRT-Guided and Manual Positioning
Time Frame: Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Within-participant comparison of the absolute residual setup deviations measured in the vertical, longitudinal, and lateral directions after AlignRT-guided positioning and manual positioning. Deviations were expressed in centimeters. Smaller absolute deviations indicate greater positioning accuracy.
Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Difference in Absolute Rotational Setup Deviations Between AlignRT-Guided and Manual Positioning
Time Frame: Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.
Within-participant comparison of the absolute residual setup deviations measured for rotation, pitch, and roll after AlignRT-guided positioning and manual positioning. Deviations were expressed in degrees. Smaller absolute deviations indicate greater positioning accuracy.
Immediately after each positioning procedure and before stereotactic radiosurgery, during the same treatment visit.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Institute of Oncology Ljubljana

Investigators

  • Principal Investigator: Klemen Salmič, MSc, Institute of Oncology Ljubljana

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2025

Primary Completion (Actual)

August 31, 2025

Study Completion (Actual)

August 31, 2025

Study Registration Dates

First Submitted

July 15, 2026

First Submitted That Met QC Criteria

July 15, 2026

First Posted (Actual)

July 21, 2026

Study Record Updates

Last Update Posted (Actual)

July 21, 2026

Last Update Submitted That Met QC Criteria

July 15, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ERIDNPVO-0017/2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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