Trial Outcomes & Findings for High Dose Rate Prostate Brachytherapy: Dose Escalation to Dominant Intra-prostatic Nodule (NCT NCT01605097)

Last Updated: 2021-07-21

Results Overview

Feasibility of dose escalation to a minimum dose of 125% of prescription to 90% of the dominant intra-porstatic lesion (DIL) volume as defined on multiparametric endo-rectal magnetic resonance imaging (mpMRI) without exceeding critical organ dose constraints (Urethral volume receiving 115%= 0, Dose to 1cc of rectal wall \< 7 Gy). 2 Fractions were performed and the mean dose to 90% of DIL volume was averaged.

Recruitment status

COMPLETED

Study phase

Target enrollment

26 participants

Primary outcome timeframe

12 months

Results posted on

2021-07-21

Participant Flow

Aim of protocol was to have 25 patients for whom dominant lesion identified on MRI and dose escalation feasible with HDR brachytherapy

One patient consented but ineligible because did not have a visible lesion on the MRI of his prostate.

Participant milestones

Participant milestones
Measure	High Dose Rate (HDR) Interstitial Brachytherapy HDR prostate brachytherapy with dose escalation to 1250 cGy to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Overall Study STARTED	26
Overall Study COMPLETED	25
Overall Study NOT COMPLETED	1

Reasons for withdrawal

Reasons for withdrawal
Measure	High Dose Rate (HDR) Interstitial Brachytherapy HDR prostate brachytherapy with dose escalation to 1250 cGy to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Overall Study Protocol Violation	1

Baseline Characteristics

High Dose Rate Prostate Brachytherapy: Dose Escalation to Dominant Intra-prostatic Nodule

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	HDR Interstitial Brachytherapy n=25 Participants HDR prostate brachytherapy with dose escalation to 1250 cGy to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Age, Continuous	63 years n=5 Participants
Sex: Female, Male Female	0 Participants n=5 Participants
Sex: Female, Male Male	25 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants
Race (NIH/OMB) White	25 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Baseline PSA ng/mL	10.4 ng/mL n=5 Participants
Gleason score Gleason 7	23 participants n=5 Participants
Gleason score Gleason 8 or 9	2 participants n=5 Participants
clinical stage Stage T1c	3 participants n=5 Participants
clinical stage Stage T2a	7 participants n=5 Participants
clinical stage Stage T2b	15 participants n=5 Participants

PRIMARY outcome

Timeframe: 12 months

Outcome measures

Outcome measures
Measure	High Dose Rate (HDR) Interstitial Brachytherapy n=25 Participants HDR prostate brachytherapy with dose escalation to 1250 centiGray (cGy) to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Average Mean Dose to 90% of DIL Volume	13.25 Grays Standard Deviation 1.1

SECONDARY outcome

Timeframe: 24 months

Population: Months to normalization of International Prostate Symptom Score following treatment.

Time to normalize International Prostate Symptom Score (months). Score range 0-35 with 35 being worst outcome. Normalization refers to a return to baseline urinary function prior to treatment.

Outcome measures

Outcome measures
Measure	High Dose Rate (HDR) Interstitial Brachytherapy n=25 Participants HDR prostate brachytherapy with dose escalation to 1250 centiGray (cGy) to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Acute Toxicity	1.5 months Interval 0.6 to 9.0

SECONDARY outcome

Timeframe: 5 years

Population: All 25 underwent dose escalation to dominant lesion in prostate to median 132% of prescription dose

Efficacy assessed by biochemical PSA response reported at median 5 year follow up.

Outcome measures

Outcome measures
Measure	High Dose Rate (HDR) Interstitial Brachytherapy n=25 Participants HDR prostate brachytherapy with dose escalation to 1250 centiGray (cGy) to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Prostate Specific Antigen(PSA) Response at 5-years	0.06 ng/ml Interval 0.02 to 0.18

Adverse Events

HDR Interstitial Brachytherapy

Serious events: 0 serious events

Other events: 5 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	HDR Interstitial Brachytherapy n=25 participants at risk HDR prostate brachytherapy with dose escalation to 1250 cGy to the MRI-defined dominant intraprostatic lesion HDR interstitial brachytherapy: 2 treatments of 1000 cGy will be delivered to the entire prostate volume while escalating the dose to the visible disease to 1250 cGy
Renal and urinary disorders late hematuria grade 1	8.0% 2/25 • Number of events 2 • Data collected for 60 months on all patients. Accrual was completed July 2013 and data collected to July 2018. CTCAE V 3.0
Gastrointestinal disorders grade 1 proctitis	12.0% 3/25 • Number of events 3 • Data collected for 60 months on all patients. Accrual was completed July 2013 and data collected to July 2018. CTCAE V 3.0

Additional Information

Dr Juanita Crook

BC Cancer

Phone: 250 712 3958

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place