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)

Summary

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.

Eligibility

Age range

18+ years

Sex

Male

Healthy volunteers

No

Interventions

• Radiation
  1.5 T Elekta Unity MR-Linac system

  Patients will receive 9 Gy/fraction (45 Gy total) for five fractions to the DIL, while the remainder of the prostate will be treated to 30 Gy in 5 fractions.

• Device
  Hydrogel rectal spacer (SpaceOAR)

  A rectal spacer will be placed one week prior to simulation to achieve a separation of approximately 1 cm between the prostate and anterior rectal wall to further minimize rectal toxicity in these patients. The hydrogel will remain in the body for about 12 weeks.

Location