Efficiency of Contemporary Off-line Adaptive Radiotherapy for Lung Cancer

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
AgeNot listed
SponsorUniversitaire Ziekenhuizen KU Leuven

About this trial

Locally advanced non-small cell lung cancer (LA-NSCLC) patients could benefit in overall and progression-free survival from regular dosimetric treatment plan adaptations during radiotherapy. This is known as adaptive radiotherapy (ART). However, implementing an adaptive radiotherapy workflow presents a highly cumbersome process. First, repeated planning-CT imaging during treatment is required, which results in additional radiation dose for patients. Second, an ART workflow includes the repetition of various manual and semi-automated tasks such as target and organ-at-risk contouring on the images and dosimetric treatment planning. These obstacles hinder widespread ART implementation.

To avoid repeated planning-CT imaging, position-verification imaging can be utilized. Modern cone-beam CT (CBCT) imaging, integrated into the treatment unit, assists radiation therapists (RTTs) in administering the dose. Recent improvements in CBCT imaging sources and detectors have enhanced image quality. Moreover, it may be possible to calculate radiation dose directly on these CBCTs. Utilizing CBCT imaging for plan adaptation could also eliminate the need for an additional CT procedure, thereby increasing patient comfort.

To address the labor-intensive contouring and treatment planning steps, CE-marked and validated commercial AI applications are already being used to support organ contouring and accelerate the treatment-planning process. These tools are currently applied to pre-treatment planning CTs. The time efficiency of these contemporary tools in a prospective ART workflow has yet to be studied, as has the feasibility of applying these applications within a CBCT-based ART workflow.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures

Patients diagnosed with non-small-cell lung cancer

Locally advanced disease (≥Stage III)

Treated with sequential or concurrent chemoradiotherapy

Disqualifiers

Small-cell lung cancer

Non-small-cell lung cancer of early stage

Mesothelioma

Trial design

Design model

Single group

Treatments tested in this trial

  • CBCT-based adaptive radiotherapy

    Device

    The objective is to temporarily implement and study the efficiency of a prospective ART workflow for LA-NSCLC using repeated planning-CT imaging. This initiative aims to contour and plan in accordance with the contemporary clinical AI-tools already being standard-of-care in the pre-treatment workflow, with a specific focus on evaluating and reporting the time efficiency of the process. Following the prospective part, we want to retrospectively study a CBCT-based ART workflow for LA-NSCLC using CBCT imaging in comparison with the CT-based ART workflow. The contours and treatment plans generated utilizing 4DCT imaging serve as ground truth. These retrospective tests are fully outside the clinical flow. We will evaluate whether it is possible to implement an adaptive workflow without repeated planning-CT imaging. For this objective, we will utilize the same commercial AI tools, with a focus on reporting both the time efficiency and the quality of contours and plans in comparison.

Treatment groups

30 Participants
are divided into 1 treatment group
Group A: CT-based Adaptive Radiotherapy applied midtreatment. Retrospective CBCT-based Adaptive comparisonExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Time required for each step of the prospective adaptive radiotherapy workflow

The total time required to complete each component of the prospective adaptive radiotherapy workflow will be quantified. Time measurements will be recorded using standardized digital workflow time-logging templates in the department's hospital document management system. The following steps will be assessed: * Acquisition of the repeated 4D planning CT * Automated organ-at-risk contouring (Syngo.via®) * Physician approval of organ-at-risk contouring * Manual tumor delineation * Knowledge-based treatment planning (RapidPlan®) * Medical physics plan review and approval * Physician plan review and approval The primary variable will be the total cumulative duration (minutes) and step-specific durations (minutes).

Time frame
From initiation of the mid-treatment 4DCT scan until final approval of the adapted treatment plan, assessed for each participant, up to 7 weeks of radiotherapy
2

Time required for each step of the retrospectively tested CBCT-based adaptive radiotherapy workflow

The total time required to complete each component of the retrospective CBCT-based adaptive radiotherapy workflow will be quantified. Time measurements will be recorded using standardized digital workflow time-logging templates in the department's hospital document management system. The following steps will be assessed: * CBCT acquisition (retrospective use of routine daily CBCT) * Preparation of the CBCT for accurate dose calculation (enhancing image quality, applying correct density to Hounsfield unit curve) * Automated organ-at-risk contouring (Syngo.via® and MIM®) * Manual tumor delineation * Knowledge-based treatment planning (RapidPlan®) The primary variable will be the total cumulative duration (minutes) and step-specific durations (minutes).

Time frame
Assessed retrospectively for each participant from the first available mid-treatment CBCT to completion of the simulated treatment plan, up to 6 months
3

Plan quality comparison using dose-volume histogram (DVH) metrics

Quality of CBCT-based or synthetic-CT-based adaptive treatment plans will be compared with reference prospective 4DCT-based plans. Metrics include: * Target coverage (i.e. iCTV, PTV) (%) * Organ-at-risk doses (i.e. lungs, spinal canal, esophagus, brachial plexi, mediastinal envelope, heart, contralateral lung) (Gy and %) * Dose deviations between CBCT-based/synthetic CT-based and 4DCT-based plans Evaluation will be performed using standard treatment planning system DVH tools.

Time frame
Assessed retrospectively after completion of radiotherapy, up to 6 months
4

Contour accuracy comparison using similarity metrics (DSC, HD, ASSD)

Contour similarity between CBCT-based (or synthetic-CT-based) contours and reference 4DCT-based contours will be evaluated. Metrics include: * Dice Similarity Coefficient (DSC) (unitless) * Hausdorff Distance (HD) (millimeters) * Average Symmetric Surface Distance (ASSD) (millimeters) Analyses will be performed using MIM®.

Time frame
Assessed retrospectively after completion of radiotherapy, up to 6 months

Secondary outcomes

Other outcomes

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