Daily Adjustment of the Radiation Dose in MRI-guided Stereotactic Radiotherapy for Tumors in the Abdominal and Pelvic Regions (ACTION)
Adaptive Fractionation in Online MR-guided SBRT for Abdominal and Pelvic Target Volumes
SBRT delivers high-dose radiation to precisely defined target volumes and is an effective locally ablative treatment option for both primary tumours and oligometastases in various settings, including lesions in the abdomen or pelvis. However, SBRT in these regions faces considerable challenges such as inter-fractional organ motion and anatomical deformation, which can compromise treatment precision.
MR-guided SBRT offers a solution, providing superior soft-tissue contrast and enabling real-time, online treatment plan adaptation over the course of SBRT. This approach reduces the risk of geographical miss and overdose to adjacent, vulnerable OARs. Currently, MR-guided SBRT uses a fixed dose per fraction, only adjusting target volume and OAR contours for anatomical changes when performing plan adaptation. However, overlaps between planning target volumes (PTVs) and dose-limiting OARs regularly require compromises in PTV coverage. To address this, AF aims to also adjust dose per fraction based on daily PTV-OAR overlap. With this approach, more dose is applied on treatment days with less PTV-OAR overlap while less dose is applied on days with more PTV-OAR overlap. This trial assesses the feasibility of AF in MR-guided SBRT for abdominal and pelvic tumours that show PTV-overlap with one or more dose-limiting OARs, ultimately aiming to enhance PTV dose coverage without increasing toxicity.
調査の概要
研究の種類
入学 (推定)
段階
- 適用できない
連絡先と場所
研究連絡先
- 名前：Jan Unkelbach, Prof. Dr. rer. nat.
- 電話番号：+41 44 255 85 49
- メール：jan.unkelbach@usz.ch
研究連絡先のバックアップ
- 名前：Lena Kretzschmar, Dr. med.
- メール：lena.kretzschmar@usz.ch
研究場所
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Canton of Zurich
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Zurich、Canton of Zurich、スイス、8091
- 募集
- University Hospital Zurich
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参加基準
適格基準
就学可能な年齢
- 大人
- 高齢者
健康ボランティアの受け入れ
説明
Inclusion Criteria:
- Karnofsky performance status ≥70
- Abdominal or pelvic malignancy (primary or secondary) with previous histological confirmation of the primary tumour, amenable to SBRT in 5 fractions (excluding SBRT to primary tumour in patients with prostate cancer) Note: patients with primary prostate cancer are eligible, but SBRT to the primary tumour in the prostate cannot be performed within the study
- Total prescribed SBRT dose > 30 Gy (constraint for dose-limiting OAR) over 5 treatment fractions
- Distance of the GTV ≤ 1 cm from at least one dose-limiting OAR (bowel / duodenum / stomach) in the available diagnostic images
- Patients able to tolerate long (approximately 60 minutes) treatment time according to clinical evaluation of the treating radiation oncologist
- Patients willing and able to comply with scheduled visits, treatment, and other trial procedures
Exclusion Criteria:
- Previous radiation therapy directly overlapping with planned SBRT (type I re-irradiation)
- More than one PTV irradiated in the same plan
- Contraindications for MRI, e.g., patients with metal fragments or implanted devices that are not MR compatible such as certain types of pacemakers and aneurysm clips or severe claustrophobia
- SBRT not indicated or not possible
- Inability to follow the procedures of the trial, e.g. due to language problems of the participant
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：処理
- 割り当て：非ランダム化
- 介入モデル：並列代入
- マスキング：なし（オープンラベル）
武器と介入
参加者グループ / アーム |
介入・治療 |
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実験的：RT with AF
Patients with PTV/OAR overlap will receive AF, with dose adapted daily based on anatomy.
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The fraction dose to the PTV will be adapted based on the volume overlap of PTV and the dose-limiting OAR(s) (bowel / duodenum / stomach) on the planning MRI scan of the day ("geometry-of-the-day").
The treatment plan is then approved by the treating physician and independently verified according to department-internal standard.
MR-guided fraction dose adaptation will be repeated at each of the 5 fractions, until the prescribed total dose is reached.
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アクティブコンパレータ：RT without AF
Patients without PTV/OAR overlap will receive standard fractionated treatment.
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Patients that qualify for inclusion in the study but for whom AF is no viable treatment due to lacking PTV/OAR overlap in the planning scans.
These patients are treated according to clinical standard of care (SoC), i.e. without dose adaptation, and function as a control group.
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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Proportion of patients with successful daily dose adaptation
時間枠：from enrollment to end of treatment at 1-2 weeks
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Proportion of patients treated with daily dose-adapted treatment, who received at least one fraction of non-uniformly fractionated treatment with expectation of a benefit in PTV-coverage of ≥ 1ccGy
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from enrollment to end of treatment at 1-2 weeks
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二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Acute treatment toxicities
時間枠：during treatment (1-2 weeks) and until 90 days after
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Acute treatment toxicities for all included patients measured with Common Terminology Criteria for Adverse Events
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during treatment (1-2 weeks) and until 90 days after
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Interfractional variation in PTV/OAR overlap volume
時間枠：during treatment (1-2 weeks)
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interfractional variation in PTV/OAR overlap volume, in cc
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during treatment (1-2 weeks)
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Interfractional variation in GTV/OAR distance
時間枠：during treatment (1-2 weeks)
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interfractional variation in GTV/OAR distance, in mm
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during treatment (1-2 weeks)
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Dosimetric difference in PTV-coverage between algorithm-based calculation and the reference plan
時間枠：after end of treatment (2 weeks after last fraction)
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PTV coverage quantified as the area above the dose-volume-histogram curve measured in cc x Gy
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after end of treatment (2 weeks after last fraction)
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協力者と研究者
スポンサー
捜査官
- 主任研究者：Reinhardt Krcek, Dr. med.、University of Zurich
研究記録日
主要日程の研究
研究開始 (実際)
一次修了 (推定)
研究の完了 (推定)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (実際)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
本研究に関する用語
追加の関連 MeSH 用語
その他の研究ID番号
- RAO-25-019
- 2026-00067 (その他の識別子：BASEC)
個々の参加者データ (IPD) の計画
個々の参加者データ (IPD) を共有する予定はありますか?
医薬品およびデバイス情報、研究文書
米国FDA規制医薬品の研究
米国FDA規制機器製品の研究
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