Evaluation of Tumor Control Based on Serial Multiparametric MRI and Post-Treatment Biopsies For Patients Treated With Dose Intensification to the Dominant Intra-Prostatic Lesion (DIL) Using Ultra-Hypofractionated, MR-Guided Radiotherapy (TUMORNATOR I)
The purpose of this study is to assess the impact of this MR-guided radiotherapy on tumor control of the dominant intraprostatic lesion among patients with intermediate risk prostate cancer. This study of Radiotherapy to the Prostate and Dominant Lesion Using Ultra-Hypofractionated, MR-adaptive Radiation Therapy aims to evaluate tumor control after definitive ultra-hypofractionated external beam radiation therapy (including a simultaneously delivered high-dose boost to a dominant lesion as detected on prostate magnetic resonance imaging (MRI)) in patients with intermediate-risk prostate cancer. This will incorporate the use of multiparametric MRI for target segmentation and the use of the MR-linac with adaptive radiation planning to treat the prostate gland, incorporating a dose boost to the dominant intraprostatic lesion (DIL) that is visible on T2-weighted and diffusion-weighted imaging and de-escalation of dose to the remainder of the prostate.
• Intermediate-risk prostate cancer patients will be eligible for this study. Risk groups will be assigned as per National Comprehensive Cancer Network (NCCN) guidelines. Intermediate-risk patients will be defined as:
‣ PSA 10-20 ng/ml or
⁃ Gleason score = 7 or
⁃ Clinical stage T2b/T2c (T2b: the tumor has spread to more than one-half of one side of the prostate, but not to both sides. T2c: the cancer has invaded both sides of the prostate)
• Age \> 18
• Karnofsky Performance Status (KPS) \> 80
• Prostate size \< 90 cc
• Presence of a T2-visible prostatic lesion with maximum dimension of ≥ 0.5 cm and no more than two additional disease foci with a documented Prostate Imaging Reporting and Data System (PIRADS) 4-5 lesion
• MRI findings: Lesion may contact the capsular edge, possible extracapsular extension (ECE) permitted
• International Prostate Symptom Score \< 18
• Satisfy all MRI screening criteria and be willing to fill out the standard MRI screening form