longer term efficacy data involve delivery of HDRB br monoth
longer-term efficacy data involve delivery of HDRB
monotherapy in 4 fractions with more than 93% biochemical control at 5 years.11,14,17 To mimic the LDR
experience by increasing patient convenience and avoid-ing hospitalization and immobilization, less-fractionated
regimens with similar efficacy are emerging, although the follow-up is relatively short (1.6-4.4 years).9,15,18-20 HDRB as monotherapy was associated with decreased
acute and late genitourinary toxicity rates compared with LDRB.9,14,21 Grills et al compared LDRB using Palladium-
spective study compared HDRB monotherapy to LDRB with or without EBRT for localized prostate cancer. The authors reported similar PSA control rates at 5 years. As for toxicity, higher rate of grade 2 acute urinary toxicity was found in the LDRB (43%) group compared with the HDRB monotherapy group (12.3%, P < .0001). However, no difference was found in late grade 2 urinary toxicities between the 2 groups.12 A quality of life (QoL) study showed a return to baseline International Prostate Symptom Score (IPSS) levels at 12 weeks with HDRB,24 which is significantly quicker than with LDRB (for which return to baseline scores can take up to 12 months).
HDRB monotherapy is therefore a promising new treatment modality for patients with favorable-risk pros-tate cancer. It appears less toxic in the urinary domain and equivalent in terms of tumor control. To establish the role of HDRB as monotherapy, we conducted a pilot phase 2 randomized study evaluating the differences in health-related QoL (HRQOL) in the urinary domain between LDRB and HDRB as primary objective. Local tumor control and biochemical failure will be evaluated as sec-ondary objectives with a repeat prostate biopsy at 36 months and serial PSA measurements, respectively, once adequate follow-up has been reached.
Advances in Radiation Oncology: --- 2019 HDR vs LDR brachytherapy for prostate cancer 3
Methods and Materials
This is a phase 2, multi-institutional, randomized pilot study comparing LDRB using Iodine-125 Tigecycline implant to a total dose of 144 Gy against HDRB single-fraction 19-Gy monotherapy in patients with low- and favorable intermediate-risk prostate cancer. The clinical trial was registered on ClinicalTrials.gov (NCT02628041) and approved by the 3 participating institutions’ research ethics boards.
The specific goals of the pilot study were the following:
1. Accrual of 30 patients across 3 institutions in <12 months
2. Complete follow-up in at least 90% of all accrued patients
3. Less than 5% of major deviations on dose-volume constraints
4. At least 80% compliance in filling out HRQOL questionnaires
The pilot study was deemed successful if all those criteria were met.
The primary objective was to evaluate the differences in HRQOL in the urinary domain between patients treated with LDRB and HDRB at 3 months using the Expanded Prostate Cancer Index Composite (EPIC)-26 short form.25 The 3-month cut-off was chosen as the primary endpoint based on several studies revealing peak urinary symptoms at 3 to 6 months.26-32 The EPIC score is the most used HRQOL instrument; it has been validated in men with prostate cancer33 and shown to be a robust tool with good psychometrics.34-36 The validated French version of the EPIC was used in French-Canadian patients.37 Secondary objectives were to compare HRQOL in the urinary, bowel, and sexual domains to evaluate differences in urinary function using the IPSS and to determine the time to IPSS resolution.
>20 ng/mL, evidence of nodal or distant metastases, pre-vious pelvic radiation therapy, previous transurethral resection of the prostate, use of androgen deprivation therapy, and connective tissue or inflammatory bowel dis-ease. Subjects were randomized to 1 of the 2 treatment arms using block randomization. The use of a reductase in-hibitors was not allowed within 2 weeks of randomization and use after the procedure was not regulated. A washout period of 2 weeks was required before randomization.