Erectile Function PRESERVation in Definitive Radiotherapy for Prostate Cancer by MRI-Enhanced Adaptive Sparing of the Neurovascular Bundle (EF-PRESERVE)
Radiotherapy is a standard and highly effective treatment for prostate cancer that is confined to the prostate gland. One modern approach, called stereotactic body radiotherapy (SBRT), delivers treatment in just five sessions and has been shown to control prostate cancer as well as longer treatment schedules. Large clinical studies have demonstrated excellent cancer control rates after SBRT.
Although SBRT is effective, some men experience worsening erectile function after treatment. Researchers believe that reducing radiation exposure to the nerves and blood vessels involved in erections, known as the neurovascular bundles (NVBs), may help preserve sexual function.
The EF-PRESERVE study is evaluating whether a specialized MRI-guided treatment approach can safely reduce radiation dose to these structures while still delivering effective treatment to the prostate cancer.
調査の概要
状態
状態
条件
条件
介入・治療
介入・治療
詳細な説明
Stereotactic body radiotherapy (SBRT) has evolved from an experimental modality into a guideline-supported treatment option for localized prostate cancer. Initial pooled consortium data across 1,100 patients demonstrated high efficacy and acceptable toxicity, which was subsequently confirmed by prospective phase III trials. The HYPO-RT-PC trial established the non-inferiority of 42.7 Gy in seven fractions, while PACE-B showed that 5-fraction SBRT without androgen deprivation therapy (ADT) achieved equivalent 5-year biochemical or clinical failure-free survival compared to conventional or moderately hypofractionated schedules (95.8% vs. 94.6%). Nevertheless, erectile dysfunction remains a frequent late toxicity, with clinician-reported CTCAE Grade more than 2 erectile dysfunction rising from 18% at baseline to 26.4% five years post-SBRT in PACE-B.
To mitigate this functional decline, the EF-PRESERVE study incorporates daily adaptive magnetic resonance imaging (MRI). Because standard cone-beam computed tomography (CBCT) lacks sufficient soft-tissue resolution to visualize structures like the neurovascular bundle (NVB), the ARTEMIS workflow acts as a scaleable alternative to integrated MR-linacs.
Patients are scanned on a dedicated MRI simulator to adjust target and NVB contours daily, then transferred via a dedicated shuttle system directly to a CE-marked CBCT linear accelerator for radiotherapy delivery.
研究の種類
研究の種類
入学 (推定)
入学
段階
段階
- 適用できない
連絡先と場所
研究連絡先
研究連絡先
- 名前：Tiuri Kroese, MD PhD
- 電話番号：+41 44 255 41 32
- メール：tiuri.kroese@usz.ch
研究連絡先のバックアップ
- 名前：Matthias Guckenberger, Prof. Dr. med
- 電話番号：+41 44 255 29 30
研究場所
-
-
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Zurich、スイス
- University Hospital Zurich
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コンタクト：
- Tiuri Kroese, MD PhD
- 電話番号：+41 44 255 41 32
- メール：tiuri.kroese@usz.ch
-
-
参加基準
適格基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
Inclusion Criteria:
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Age ≥18 years
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Histologically confirmed, low- or intermediate risk localized prostate cancer eligible for definitive prostate SBRT according to NCCN criteria as (Appendix 1):
- cT1-cT2 and
- PSA <20 ng/ml and
- Gleason <8
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At least at one side the DIL ≥5 mm from the NVB
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WHO/ECOG performance status 0-2
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Sexually active patients (i.e. satisfactory penetrative intercourse over the last 4 weeks)
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Life expectancy >5 years
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If ADT planned during radiotherapy:
- Only short-course ADT for in total ≤6 months using oral GnRH-antagonists (e.g. Relugolix) for rapid testosterone recovery.
Exclusion Criteria:
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DIL within <5 mm to NVB at both sides
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High risk localized prostate cancer according to NCCN criteria as:
- cT3-cT4 or
- PSA ≥20 ng/ml or
- Gleason ≥8
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Non-localized prostate cancer (i.e. cN1 or cM1)
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Insufficient erectile function preventing satisfactory penetrative intercourse (i.e. erectile dysfunction CTCAE (v6.0) Grade 3)
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Sexually inactive patients (i.e. no penetrative intercourse over the last 4 weeks).
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Previous pelvic radiotherapy (at any time)
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Previous definitive treatment for prostate cancer (radiotherapy or prostatectomy at any time)
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Contraindication to repeated MRI
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Unable to lie in a supine position for estimated 30 min
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Inability or contraindications to undergo the investigated intervention,
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Clinically significant concomitant diseases,
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Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc
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：なし
- 介入モデル：単一グループの割り当て
- マスキング：なし（オープンラベル）
アーム数
武器と介入
参加者グループ / アーム参加者グループ / アーム |
介入・治療介入・治療 |
|---|---|
|
実験的：Adaptive MR-Enhanced SBRT with NVB Sparing
Participants undergo ultra-hypofractionated stereotactic body radiotherapy (SBRT) delivered in 5 fractions. Prior to each fraction, patients are imaged on a MRI simulator to evaluate and adapt target volumes and neurovascular bundle (NVB) contours. Using the ARTEMIS transfer shuttle system, patients are moved directly to a standard C-arm CBCT linear accelerator. The NVB will be spared during radiotherapy delivery while maintaining a minimum target dose of 40 Gy to the dominant intraprostatic lesion (DIL). If clinically indicated, concurrent short-course androgen deprivation therapy (under 6 months) is limited strictly to oral GnRH antagonists (e.g., Relugolix). |
Patients receive daily adaptive ultra-hypofractionated SBRT (5 fractions) utilizing the ARTEMIS workflow. Before each fraction, patients undergo low-field MRI to adapt target and neurovascular bundle (NVB) contours based on daily anatomical changes. Patients are transferred in treatment position to a standard CBCT linear accelerator via a shuttle system. Radiotherapy intentionally spares the NVB (unilaterally or bilaterally depending on tumor proximity) to preserve erectile function, while ensuring the dominant intraprostatic lesion (DIL) receives at least 40Gy. Additional erection-related structures (internal pudendal artery, penile bulb, corpus cavernosum) are contoured for dosimetric analysis. Concurrent short-course ADT (not more than 6 months), if indicated, is restricted to oral GnRH antagonists (Relugolix) to allow rapid testosterone recovery. |
この研究は何を測定していますか？
主要な結果の測定
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Proportion of Patients with CTCAE v6.0 Grade ≥2 Erectile Dysfunction at 1 Year Post-SBRT
時間枠：1 year post-SBRT
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Evaluates the proportion of sexually active patients who develop clinician-reported moderate to severe erectile dysfunction (defined as CTCAE v6.0 Grade ≥2) 1 year following the completion of adaptive MR-enhanced prostate SBRT with neurovascular bundle (NVB) sparing. The rate will be evaluated against historical controls from the PACE-B trial benchmark. |
1 year post-SBRT
|
二次結果の測定
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Patient-Reported Erectile Function Change via IIEF-5 Score
時間枠：Baseline, every 3 months for the first 1 year, and annually thereafter up to 5 years post-SBRT
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Evaluates changes in patient-reported erectile function using the 5-item International Index of Erectile Function (IIEF-5) questionnaire. Scores range from 5 to 25, with lower scores indicating more severe erectile dysfunction (ED). The mean score change from baseline, the proportion of patients maintaining potency, and the proportion experiencing a clinically meaningful decline (≥4 point drop in IIEF-5 score) will be evaluated across time points. |
Baseline, every 3 months for the first 1 year, and annually thereafter up to 5 years post-SBRT
|
|
Biochemical progression-free survival
時間枠：Baseline, every 3 months for the first 1 year, and annually thereafter up to 5 years post-SBRT
|
Measurement of PSA, biochemical progression is defined according to phoenix criteria. |
Baseline, every 3 months for the first 1 year, and annually thereafter up to 5 years post-SBRT
|
協力者と研究者
捜査官
捜査官
- 主任研究者：Tiuri Kroese, MD PhD、University Hospital Zurich / University of Zurich
出版物と役立つリンク
一般刊行物
- King CR, Freeman D, Kaplan I, Fuller D, Bolzicco G, Collins S, Meier R, Wang J, Kupelian P, Steinberg M, Katz A. Stereotactic body radiotherapy for localized prostate cancer: pooled analysis from a multi-institutional consortium of prospective phase II trials. Radiother Oncol. 2013 Nov;109(2):217-21. doi: 10.1016/j.radonc.2013.08.030. Epub 2013 Sep 20.
- Shore ND, Saad F, Cookson MS, George DJ, Saltzstein DR, Tutrone R, Akaza H, Bossi A, van Veenhuyzen DF, Selby B, Fan X, Kang V, Walling J, Tombal B; HERO Study Investigators. Oral Relugolix for Androgen-Deprivation Therapy in Advanced Prostate Cancer. N Engl J Med. 2020 Jun 4;382(23):2187-2196. doi: 10.1056/NEJMoa2004325. Epub 2020 May 29.
- van As N, Griffin C, Tree A, Patel J, Ostler P, van der Voet H, Loblaw A, Chu W, Ford D, Tolan S, Jain S, Camilleri P, Kancherla K, Frew J, Chan A, Naismith O, Armstrong J, Staffurth J, Martin A, Dayes I, Wells P, Price D, Williamson E, Pugh J, Manning G, Brown S, Burnett S, Hall E. Phase 3 Trial of Stereotactic Body Radiotherapy in Localized Prostate Cancer. N Engl J Med. 2024 Oct 17;391(15):1413-1425. doi: 10.1056/NEJMoa2403365.
- Brand DH, Tree AC, Ostler P, van der Voet H, Loblaw A, Chu W, Ford D, Tolan S, Jain S, Martin A, Staffurth J, Camilleri P, Kancherla K, Frew J, Chan A, Dayes IS, Henderson D, Brown S, Cruickshank C, Burnett S, Duffton A, Griffin C, Hinder V, Morrison K, Naismith O, Hall E, van As N; PACE Trial Investigators. Intensity-modulated fractionated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): acute toxicity findings from an international, randomised, open-label, phase 3, non-inferiority trial. Lancet Oncol. 2019 Nov;20(11):1531-1543. doi: 10.1016/S1470-2045(19)30569-8. Epub 2019 Sep 17.
- Nilsson P, Gunnlaugsson A, Beckman L, Widmark A, Fransson P, Hoyer M, Lagerlund M, Kindblom J, Johansson B, Bjornlinger K, Ginman C, Olsson M, Agrup M, Kjellen E, Zackrisson B, Tavelin B, Franzen L, Anderson H, Thellenberg Karlsson C. Ultra-hypofractionated versus conventionally fractionated radiotherapy for localised prostate cancer (HYPO-RT-PC): 10-year outcomes of an open-label, randomised, phase 3, non-inferiority trial. Lancet Oncol. 2026 Mar;27(3):293-301. doi: 10.1016/S1470-2045(25)00656-4. Epub 2026 Feb 5.
- Spratt DE, Srinivas S, Adra N, Ahmed B, An Y, Bitting R, Chapin B, Cheng HH, Cho SY, D'Amico AV, Desai N, Dorff T, Eastham JA, Farrington TA, Gao X, Gupta S, Ippolito JE, Karnes RJ, Kishan A, Kuettel MR, Lang JM, Lee D, Lotan T, McDonald A, Morgan T, Pessoa R, Rais-Bahrami S, Roach M 3rd, Robin T, Rosenfeld S, Scarpato KR, Shabsigh A, Szmulewitz R, Teply BA, Tward J, Valicenti R, VanderWeele D, Wong JK, Kovach E, Freedman-Cass D. Prostate Cancer, Version 3.2026, NCCN Clinical Practice Guidelines In Oncology. J Natl Compr Canc Netw. 2025 Nov;23(11):469-493. doi: 10.6004/jnccn.2025.0052.
- Tutrone R, Saad F, George DJ, Tombal B, Bailen JL, Cookson MS, Saltzstein DR, Hanson S, Brown B, Lu S, Fallick M, Shore ND. Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study. Eur Urol Oncol. 2024 Aug;7(4):906-913. doi: 10.1016/j.euo.2023.11.024. Epub 2023 Dec 23.
- Wilke L, Christ SM, Bello RD, Denney E, Fabiano S, Gabrys HS, Kefer K, Mayinger M, Nilo I, Perryck S, von der Grun J, Guckenberger M, Tanadini-Lang S. Safety in MR-enhanced daily adaptive SBRT Radiotherapy using a conventional C-arm linear accelerator: An FMEA approach. Z Med Phys. 2025 Nov;35(4):423-427. doi: 10.1016/j.zemedi.2025.05.002. Epub 2025 Jun 3.
- Teunissen FR, Wortel RC, Hes J, Willigenburg T, de Groot-van Breugel EN, de Boer JCJ, van Melick HHE, Verkooijen HM, van der Voort van Zyp JRN. Adaptive magnetic resonance-guided neurovascular-sparing radiotherapy for preservation of erectile function in prostate cancer patients. Phys Imaging Radiat Oncol. 2021 Sep 21;20:5-10. doi: 10.1016/j.phro.2021.09.002. eCollection 2021 Oct.
研究記録日
主要日程の研究
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研究開始
一次修了 (推定)
一次修了
研究の完了 (推定)
研究の完了
試験登録日
最初に提出
最初に提出
QC基準を満たした最初の提出物
QC基準を満たした最初の提出物
最初の投稿 (実際)
最初の投稿
学習記録の更新
投稿された最後の更新 (実際)
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QC基準を満たした最後の更新が送信されました
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
最終確認日
詳しくは
本研究に関する用語
キーワード
その他の研究ID番号
その他の研究ID番号
- EF-PRESERVE
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
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