Dataset Information

Deep inspiration breath hold in locally advanced lung cancer radiotherapy: validation of intrafractional geometric uncertainties in the INHALE trial.

ABSTRACT: OBJECTIVES:Patients with locally advanced non-small cell lung cancer (NSCLC) were included in a prospective trial for radiotherapy in deep inspiration breath hold (DIBH). We evaluated DIBH compliance and target position reproducibility. METHODS:Voluntary, visually guided DIBHs were performed with optical tracking. Patients underwent three consecutive DIBH CT scans for radiotherapy planning. We evaluated the intrafractional uncertainties in the position of the peripheral tumour, lymph nodes and differential motion between them, enabling PTV margins calculation. Patients who underwent all DIBH imaging and had tumour position reproducibility <8?mm were up-front DIBH compliant. Patients who performed DIBHs throughout the treatment course were overall DIBH compliant. Clinical parameters and DIBH-related uncertainties were validated against our earlier pilot study. RESULTS:69 of 88 included patients received definitive radiotherapy. 60/69 patients (87%) were up-front DIBH compliant. DIBH plan was not superior in seven patients and three lost DIBH ability during the treatment, leaving 50/69 patients (72%) overall DIBH compliant.The systematic and random errors between consecutive DIBHs were small but differed from the pilot study findings. This led to slightly different PTV margins between the two studies. CONCLUSIONS:DIBH compliance and reproducibility was high. Still, this validation study highlighted the necessity of designing PTV margins in larger, representative patient cohorts. ADVANCES IN KNOWLEDGE:We demonstrated high DIBH compliance in locally advanced NSCLC patients. DIBH does not eliminate but mitigates the target position uncertainty, which needs to be accounted for in treatment margins. Margin design should be based on data from larger representative patient groups.

SUBMITTER: Josipovic M

PROVIDER: S-EPMC6913352 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

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Deep inspiration breath hold in locally advanced lung cancer radiotherapy: validation of intrafractional geometric uncertainties in the INHALE trial.

Josipovic Mirjana M Aznar Marianne C MC Thomsen Jakob B JB Scherman Jonas J Damkjaer Sidsel Ms SM Nygård Lotte L Specht Lena L Pøhl Mette M Persson Gitte F GF

The British journal of radiology 20190926 1104

<h4>Objectives</h4>Patients with locally advanced non-small cell lung cancer (NSCLC) were included in a prospective trial for radiotherapy in deep inspiration breath hold (DIBH). We evaluated DIBH compliance and target position reproducibility.<h4>Methods</h4>Voluntary, visually guided DIBHs were performed with optical tracking. Patients underwent three consecutive DIBH CT scans for radiotherapy planning. We evaluated the intrafractional uncertainties in the position of the peripheral tumour, ly ...[more]

PMID: 31544478

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Project description:PurposeBeam gating with deep inspiration breath hold (DIBH) usually depends on some external surrogate to infer internal target movement, and the exact internal movement is unknown. In this study, we tracked internal targets and characterized residual motion during DIBH treatment, guided by a surface imaging system, for gastrointestinal cancer. We also report statistics on treatment time.Methods and materialsWe included 14 gastrointestinal cancer patients treated with surface imaging-guided DIBH volumetrically modulated arc therapy, each with at least one radiopaque marker implanted near or within the target. They were treated in 25, 15, or 10 fractions. Thirteen patients received treatment for pancreatic cancer, and one underwent separate treatments for two liver metastases. The surface imaging system monitored a three-dimensional surface with ± 3 mm translation and ± 3° rotation threshold. During delivery, a kilovolt image was automatically taken every 20° or 40° gantry rotation, and the internal marker was identified from the image. The displacement and residual motion of the markers were calculated. To analyze the treatment efficiency, the treatment time of each fraction was obtained from the imaging and treatment timestamps in the record and verify system.ResultsAlthough the external surface was monitored and limited to ± 3 mm and ± 3°, significant residual internal target movement was observed in some patients. The range of residual motion was 3-21 mm. The average displacement for this cohort was 0-3 mm. In 19% of the analyzed images, the magnitude of the instantaneous displacement was > 5 mm. The mean treatment time was 17 min with a standard deviation of 4 min.ConclusionsPrecaution is needed when applying surface image guidance for gastrointestinal cancer treatment. Using it as a solo DIBH technique is discouraged when the correlation between internal anatomy and patient surface is limited. Real-time radiographic verification is critical for safe treatments.

Project description:Highlights • Lung stereotactic body radiotherapy was performed in deep-inspiration breath-hold on a closed-bore linac, with improved treatment times and patient comfort.• Computed tomography scanning confirmed reproducible breath-hold, with tumor within 1.5 mm and 1.5°.• Planning target volumes were reduced by 67%, with consequently large reduction in healthy lung exposure. Background and purpose Tumor motion and delivery efficiency are two main challenges of lung stereotactic body radiotherapy (SBRT). The present work implemented the deep inspiration breath hold technique (DIBH) with surface guided radiation therapy (SGRT) on closed-bore linacs and investigated the correlation between SGRT data and internal target position. Materials and methods Thirteen lung SBRT patients treated in DIBH using a closed-bore gantry linac and a ring-mounted SGRT system were retrospectively analysed. Visual coaching was used to achieve DIBH with a ± 1 mm threshold window in the anterior-posterior direction. Three kV-CBCTs were added to the treatment workflow and examined offline to verify intra-fraction tumor position. Surface-based DIBH was analysed using SGRT treatment reports and an in-house python script. Data from 73 treatment sessions and 175 kV-CBCTs were studied. Correlations between target and surface positions were studied with Linear Mixed Models. Results Median intra-fraction tumor motion was 0.8 mm (range: 0.7–1.3 mm) in the anterior-posterior direction, 1.2 mm (range: 1–1.7 mm) in the superior-inferior direction, and 1 mm (range: 0.7–1.1 mm) in the left–right direction, with rotations of <1° (range: 0.6°–1.1°) degree in all three directions. Planned target volumes and healthy lung volumes receiving 12.5 Gy and 13.5 Gy were reduced on average by 67% and 54%, respectively. Conclusions Lung SBRT in DIBH with the ring-mounted SGRT system proved reproducible. The surface monitoring provided by SGRT was found to be a reliable surrogate for internal target motion. Moreover, the implementation of DIBH technique helped reduce target volumes and lung doses.

Dataset Information

Deep inspiration breath hold in locally advanced lung cancer radiotherapy: validation of intrafractional geometric uncertainties in the INHALE trial.

Publications

Deep inspiration breath hold in locally advanced lung cancer radiotherapy: validation of intrafractional geometric uncertainties in the INHALE trial.

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