A Study of MRI-guided High-dose Radiation Therapy in Prostate Cancer

Study Overview
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Brief Summary
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One of the usual approaches to treating intermediate-risk prostate cancer is a type of radiation therapy called SBRT (stereotactic body radiation therapy). SBRT delivers higher than standard doses of radiation over a lower number of treatment sessions. However, there is a 20% chance that intermediate-risk prostate cancer will come back after this treatment. The purpose of this study is to find out whether giving an even higher dose (a boost dose) of radiation directly to the main tumor and the standard dose of radiation to the rest of the prostate may cure the cancer or prevent it from coming back for a longer period of time while causing few side effects.

Official Title
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A Phase II Study of Radiotherapy to the Prostate and Dose Intensification to the Dominant Intra- Prostatic Lesion (DIL) Using Ultra-Hypofractionated, MR-Guided Radiotherapy

Conditions
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Prostate Cancer

Intervention / Treatment
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* Radiation: Radiation Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Intermediate-risk prostate cancer patients will be eligible for this study. Risk groups will be assigned as per NCCN guidelines. Intermediate-risk patients will be defined as: PSA 10-20 ng/ml or Gleason score = 7 or Clinical stage T2b/T2c or Additionally, patients will be required to meet all of the following criteria: Age ≥ 18 Karnofsky Performance Status (KPS) ≥ 80 (Appendix 1) Prostate size ≤ 80 cc Presence of a T2-visible prostatic lesion with maximum dimension of ≥ 0.5 cm and no more than one additional disease focus MRI findings: Lesion may contact the capsular edge, possible extracapsular extension (ECE) permitted International Prostate Symptom Score ≤ 15 Satisfy all MRI screening criteria and be willing to fill out the standard MRI screening form Exclusion Criteria: Patient will be excluded if they meet any one of the following criteria: Gleason score >7 PSA >20 Prior or concurrent androgen deprivation therapy for prostate cancer MRI findings: suspicious for/probable ECE MRI findings: >2 disease foci identifiable Evidence of metastatic disease on bone scan or MRI/CT MRI ineligibility due to: the presence of a cardiac pacemaker, defibrillator, or other implanted metallic or electronic device which is considered MR unsafe; severe claustrophobia; inability to lie flat for the duration of the study; etc. Metallic implant or device in the pelvis that might distort the local magnetic field and compromise quality of mp-MRI Lateral pelvic separation greater than 50 cm and/or anterior-posterior separation greater than 35 cm which are incompatible with MRCAT reconstruction Contra-indications to receiving gadolinium contrast KPS < 80 Pelvic or prostate MRI or CT (MRI preferred) evidence of radiographic T3, T4, or N1 disease Prior history of transurethral resection of the prostate Prior history of urethral stricture Prior history of pelvic irradiation History of inflammatory bowel disease Unable to give informed consent Unable to complete quality of life questionnaires Abnormal complete blood count, including any of the following: Platelet count less than 75,000/ml Hb level less than 10 gm/dl WBC less than 3.5/ml Abnormal renal function tests (creatinine > 1.5)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Prostate cancer patients<br>Intermediate-risk prostate cancer patients will be eligible for this study. Risk groups will be assigned as per NCCN guidelines. Intermediate-risk patients will be defined as: PSA 10-20 ng/ml or Gleason score = 7 Clinical stage T2b/T2c | Radiation: Radiation Therapy<br>* Patients enrolled in this study will undergo ultra-hypofractionated radiation utilizing MR guided, daily online adaptive planning. Patients will receive a standard dose of 8 Gy/fraction for five fractions for a total dose of 40 Gy to the prostate with a simultaneously-delivered boost of 9 Gy for five fractions (clinically non-standard dose of 45 Gy total) to a single dominant lesion with a maximum dimension of at least 0.5 cm, as determined on the pretreatment diagnostic T2 MRI imaging. In the setting of two similarly-sized dominant lesions, both will be boosted.<br>* Other names: SBRT;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of pretreatment biopsy with post-treatment biopsy | The primary outcome of efficacy will be studied using post -treatment biopsies. To demonstrate efficacy of dose escalation to the DIL, the investigators aim to reduce the positive post-treatment biopsy rates at 24 months for intermediate risk disease from 20% to 10%. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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SBRT, stereotactic body radiation therapy, prostate cancer, 21-308, Memorial Sloan Kettering Cancer Center