Hypersight and Ethos In Pediatric Radiotherapy (Peds Ethos)

Hypersight and Ethos In Pediatric Radiotherapy (Peds Ethos)

This is a single-center, prospective pilot study evaluating the utility of HyperSight CBCT imaging and Ethos adaptive radiation planning in pediatric patients receiving radiation therapy for non-cranial tumors.

Twenty patients aged 18 or under will be enrolled. Participants will receive standard-of-care radiation therapy, with the addition of twice-weekly HyperSight CBCT scans. These scans will be used to assess anatomical changes and generate adapted radiation plans using the Ethos platform. Radiation oncologists and radiation therapists will independently evaluate the need for adaptation, and adapted vs. scheduled plans will be compared using dosimetric and anatomical similarity metrics.

An optional sub-study will allow anonymized imaging and planning data to be shared with Varian Medical Systems. The study duration will match the patient's treatment course, typically 1-6 weeks, with no additional follow-up beyond standard care.

Study Overview

• Status: Recruiting
• Conditions: Cancer
• Intervention / Treatment: Device: HyperSight CBCT scans

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dana Keilty, MD; Phone Number: 6513 416-946-4501; Email: dana.keilty@uhn.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 2M9
      • Recruiting
      • Princess Margaret Cancer Centre
      • Contact: Dana Keilty, MD; Phone Number: 6513 416-946-4501; Email: dana.keilty@uhn.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient (paediatric or adolescent) age 18 or under receiving at least 5 days of radiation therapy
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 3

Exclusion Criteria:

- Patients with primary cranial tumours will be excluded due to the low expected utility of non-contrast CT scans in the delineation of brain edema and brain substructures.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Imaging; Participants will receive standard-of-care radiation therapy, with the addition of twice-weekly HyperSight CBCT scans.	Device: HyperSight CBCT scans; During the standard of care pediatric radiation treatment, a Cone Beam Computed Tomography (CBCT) image is taken after the patient is positioned on the radiation treatment table. This image, captured using equipment built into the treatment machine, helps ensure accurate alignment and allows assessment of tumor or tissue changes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dice Similarity Coefficient	Change in Tumor and OAR Anatomy During Pediatric Radiation Therapy Using HyperSight CBCT and Ethos Adaptive Replanning. This outcome measures how tumor and organ-at-risk (OAR) anatomy changes during pediatric radiation therapy using HyperSight CBCT.	From baseline (start of radiation treatment) to end of treatment, approximately 6 to 8 weeks.
Hausdorff distance	Change in Tumor and OAR Anatomy During Pediatric Radiation Therapy Using HyperSight CBCT and Ethos Adaptive Replanning. This outcome measures how tumor and organ-at-risk (OAR) anatomy changes during pediatric radiation therapy using HyperSight CBCT. This will be measured in mm.	From baseline (start of radiation treatment) to end of treatment, approximately 6 to 8 weeks.
Volume differences	Change in Tumor and OAR Anatomy During Pediatric Radiation Therapy Using HyperSight CBCT and Ethos Adaptive Replanning. This outcome measures how tumor and organ-at-risk (OAR) anatomy changes during pediatric radiation therapy using HyperSight CBCT. This will be measured in cm^3.	Time Frame: From baseline (start of radiation treatment) to end of treatment, approximately 6 to 8 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of cone beam CT	Using the 5 liker scale	From baseline to end of treatment (approximately 6 to 8 weeks)
Organ motion	Does the dose to the organ that day violate the prespecified constraints	From baseline to end of treatment (approximately 6 to 8 weeks)
Feasibility of Conformal Planning in Traditionally Field-Based Diseases	All target coverage goals achieved with conformal planning measured in percentage (%).	From baseline to end of treatment (approximately 6 to 8 weeks)
Feasibility of Conformal Planning in Traditionally Field-Based Diseases	All target coverage goals achieved with conformal planning measured in volume (mm^3)	From baseline to end of treatment (approximately 6 to 8 weeks)
Feasibility of Conformal Planning in Traditionally Field-Based Diseases	All target coverage goals achieved with conformal planning measured in dose (gy)	From baseline to end of treatment (approximately 6 to 8 weeks)
Dosimetric Impact of Adaptive Radiation Therapy	Measures the differences in accumulated radiation dose to the tumor and organs at risk (OARs) between adapted and non-adapted treatment plans using dose-volume metrics.	From baseline to end of treatment (approximately 6 to 8 weeks)
Safety of Minimized Target Expansion Volumes	Evaluates whether reducing target margins in adaptive planning maintains safe dose coverage while avoiding increased exposure to surrounding healthy tissue. All target coverage goals achieved with smaller PTV sizes. It's a pre-defined metric that is specific to the tumour type. A common example is the dose to 95% of the PTV should be >95% of the prescription dose.	From baseline to end of treatment (approximately 6 to 8 weeks)
Integration of Radiation Therapy Proficiencies in Adaptive Planning	Image review, contour adjustments, and plan selection during daily treatment sessions. Measured >=0.70 Dice Similarity Coefficient between radiation oncology and radiation therapy delineations.	From baseline to end of treatment (approximately 6 to 8 weeks)

Collaborators and Investigators

• Sponsor: University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): April 14, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: May 26, 2025
• First Submitted That Met QC Criteria: April 9, 2026
• First Posted (Actual): April 14, 2026

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 14, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms
• Other Study ID Numbers: 25-5372

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: To be discussed with PI

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No