A Phase III Randomized Pilot Study of Low Dose Rate Compared to High Dose Rate Prostate Brachytherapy for Favourable Risk and Low Tier Intermediate Risk Prostate Cancer
This study will offer men with intermediate risk prostate cancer who are suitable for, and
interested in, prostate brachytherapy, the opportunity to be randomized between low dose
rate (LDR) brachytherapy using permanent implantation of radioactive seeds (the current
standard of care in BC) and high dose rate (HDR) or temporary brachytherapy which is also
available as a standard of care in BC but only when used as a boost in addition with
external beam radiation therapy. In addition, men will be offered the opportunity for testing the
aggressiveness of their cancer using Cell Cycle Progression Gene Profile.
- The difference in Quality of Life in the urinary domain between LDR and HDR brachytherapy.
- Quality of Life in the bowel and sexual domains
- Time to return to baseline +/- 3 points for the International Prostate Symptom Score
- Acute and long term toxicity
- TRUS- MRI fusion
- Biochemical Outcome
- Histologic Outcome
- Cell cycle progression score
To conduct a Phase III randomized trial for favourable tier intermediate risk prostate cancer
and selected favourable risk tumours to evaluate the difference in Quality of Life in the
urinary domain between LDR and HDR brachytherapy.
Because of more rapid dose delivery with HDR compared to LDR brachytherapy (15 minutes vs. 6
months) and more precise control of dose to adjacent critical structures (prostatic and
bulbo-membranous urethra and anterior rectal wall), HDR prostate brachytherapy has been
associated with more rapid recovery from acute symptoms and a more favourable side effect
protocol when used as a boost in combination with external beam radiation therapy. The hypothesis
is that this advantage will be maintained when brachytherapy is used as monotherapy without
the addition of external beam radiation.
In British Columbia, LDR prostate brachytherapy is the current standard for selected men
with favourable risk prostate cancer who are not suitable for, or willing to accept active
surveillance, and for men with favourable intermediate risk prostate cancer. LDR
brachytherapy has been available in BC for over 15 years and is highly effective with 7-year
biochemical disease-free rates of ~ 95%. However, this type of treatment has a prolonged
recovery phase with return to baseline urinary function taking 6 to 12 months. This is
partly due to the fact that the radiation is delivered over a 6 month period from the
implanted seeds, and partly due to uncertainty in final seed placement. HDR brachytherapy
has the advantage of delivering treatment very rapidly over 15-20 minutes, and also exploits
the radiobiologic nature of prostate cancer which is more responsive to large doses of
radiation therapy. Experience with using HDR brachytherapy as a boost has shown a much reduced
impact on quality of life.
Primary: To evaluate the difference in QOL in the urinary domain between LDR and HDR
brachytherapy using the urinary domain of the EPIC prostate cancer specific QOL
- To assess differences in the bowel and sexual domains of the
EPIC prostate cancer specific QOL questionnaire between the 2 treatments
- To asses time to recovery of the IPS Score which is widely
used to assess urinary function after prostate cancer treatment. The time to
return to baseline +/- 3 points will be determined.
- Acute and long-term toxicity will be graded using the Common
Terminology Criteria for Adverse Events (CTCAE V4) at each follow up time point
- TRUS- MRI fusion will be developed within our planning
software to facilitate treatment planning
- To assess treatment efficacy, PSA will be recorded every 6
months to 5 years and then annually to 10 years and prostate re-biopsy will be
performed at 36 months after radiation therapy.
For those patients consenting to targeted biopsies under
anaesthesia at the start of their brachytherapy procedure (separate consent)
- Verify MRI-TRUS fusion accuracy
- Correlate Cell Cycle Progression scores with outcome.
Multiparametric MRI (mpMRI)will be performed on all men as a
staging procedure to ensure appropriateness for brachytherapy as monotherapy
(without the addition of external beam radiation therapy or hormone therapy).
The value of mpMRI in staging prostate cancer is widely recognized. Previous
studies have shown that over 90% of intermediate risk cancers are visible on
mpMRI. The MR images will be fused with the planning trans rectal ultrasound
(TRUS) for each patient, ensuring adequate dose coverage of the lesion.
For those patients consenting to optional biopsies under
anesthesia, accuracy of the fusion will be verified by obtaining 2 biopsies of
the visualized lesion under TRUS guidance at the start of the brachytherapy
Follow up is as per standard practice to assess urinary,
bowel and sexual side effects. In addition to the standard forms, patients will
also complete an EPIC questionnaire. The questionnaires are completed every 3
months for 1 year and then every 6 months to 3 years and then annually, as per
the standard follow up schedule.
Once the biopsy material has been pathologically confirmed
to contain the target lesion, the aggressiveness will be assessed through Cell
Cycle Progression (CCP) Gene Profile testing.
Men may be randomized to the type of brachytherapy and
decline the biopsies. This initial protocol is a Pilot that will test
feasibility of the randomization (patient acceptance). The aim is to accrue 60
men over 18-24 months and if achieved then apply to expand to a total of 200
View this trial on ClinicalTrials.gov