Multi-parametric MRI Guided Dose-Escalated Radiotherapy For Localized Prostate Cancer: A Prospective Phase II Trial

Committee/Faculty

Co-Author(s)

PB

Philip Blumenfeld

MD
Sharett Institute of Oncology
Jerusalem, Illinois, United States

Disclosure: Disclosure information not submitted.
SR

Soumyajit Roy

MBBS
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
MC

Mudit Chowdhary

MD
Lifespan Cancer Institute at Rhode Island Hospital
Providence, Rhode Island, United States

Disclosure: Disclosure information not submitted.
KK

Kevin King

MD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.

Presenting Author(s)

NC

Nathaniel B. Camden, n/a

MD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Co-Author(s)

SS

Stephanie Shors

MD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
RB

Ryan Braun

MD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
GW

Greg White

MD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
JT

Julius Turian

PhD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
Dian Wang, MD, PhD

MD, PhD
Rush University Medical Center
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.

Purpose: To determine the late toxicity associated with dose escalation to PI-RADS III-V lesions on multiparametric MRI with an image-guided combined IMRT-SBRT approach in men with localized prostate cancer.

Methodology: In this phase II trial patients with localized prostate cancer with clinical tumor stage T1-T3bN0 and at least one PIRADS III-V lesion were recruited to receive 45 Gy in 25 fractions to the prostate and seminal vesicles followed by a boost of 18 Gy in 3 fractions to the prostate with a simultaneous integrated boost 21 Gy in 3 fractions to the PI-RADS lesion(s). The primary endpoint was the cumulative incidence of late grade ≥3 genitourinary and gastrointestinal toxicity by 18 months (NCI CTCAE v4.0).

Results: 50 patients were enrolled in this study. 43 patients completed at least 18 months of follow-up. The cumulative incidence of grade 1, 2, and 3 late genitourinary toxicity at 18 months was 18%, 53%, and 2%. One patient was noted to have grade 3 hematuria and needed cystoscopy guided cauterization. The cumulative incidence of grade 1, 2, grade 3 late gastrointestinal toxicity at 18 months was 31%, 4%, and 0%. No grade 3 acute gastrointestinal or genitourinary toxicities were observed. At a median follow-up of 37 months, 3 patients developed biochemical recurrence, each with distant bone metastases. There were no locoregional failures.

Conclusions: Multiparametric MRI-guided dose escalation to PI-RADS III-V lesions using an image-guided combined IMRT-SBRT is associated with an acceptable risk of late gastrointestinal and genitourinary toxicity and excellent locoregional control.

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