Hemi‐ablative low‐dose‐rate prostate brachytherapy for unilateral localised prostate cancer

Abstract

Objectives To report clinical outcomes of the Hemi‐Ablative Prostate Brachytherapy (HAPpy) trial evaluating treatment‐related toxicity and effectiveness of hemi‐gland (HG) low‐dose‐rate (LDR) prostate brachytherapy as a focal approach to control unilateral localised prostate cancer. Patients and Methods Single institution phase IIS pilot study of patients treated with focal 4D Brachytherapy™ (BXTAccelyon, Burnham, Buckinghamshire, UK). The primary outcome was patient‐reported toxicity 24 months after implant. The secondary outcome was assessment of disease control. Outcomes in HG patients were compared to whole‐gland (WG) controls obtained from our prospective cohort registry by negative binomial and linear regression models. Results Pre‐treatment demography was similar between the 30 HG patients and 362 WG controls. Post‐implant dosimetry was similar for the prostate gland target volumes and significantly reduced for the urethra and bowel in HG patients relative to WG controls, but this did not translate into a difference in post‐implant mean symptom scores between the two groups. Nevertheless, the change in score from baseline indicated that the impact on pre‐treatment symptom status was less after HG implants. Only HG patients showed a return to baseline urinary scores as early as 12 months. Sexual potency was conserved in 73% and 67% of HG and WG patients, respectively (P = 0.84). Post‐implant prostate‐specific antigen (PSA) kinetics revealed that baseline PSA was reduced at 24 months by 78% and 88% in HG and WG patients, respectively (P < 0.05). Treatment relapse occurred in one (3%) HG patient 55 months after implant and in nine (3%) WG patients at 32–67 months after implant. Conclusion This pilot study suggests that treatment‐related toxicity and biochemical outcomes after HG implants are broadly similar to those observed with WG treatment despite the lower dose delivered by HG implants.

Focal low-dose-rate prostate brachytherapy for low- and intermediate-risk prostate cancer

“…It has been reported that the treatmentrelated toxicities and biochemical outcomes of hemigland LDR brachytherapy for unilateral localized prostate cancer are broadly similar to those of whole-gland brachytherapy. Although, post-implant dose to the urethra and rectum was significantly lower in hemi-gland brachytherapy, compared with whole-gland brachytherapy [22]. It is difficult to conclude which focal LDR brachytherapy (hemi-gland vs. MRI-based target) is superior at this time.…”

Detailing Sexual Outcomes After Focal Therapy for Localised Prostate Cancer: A Systematic Review and Meta-analysis

“…Most causes of dropout were not stated or simply described as "lost to follow-up". Reasons stated when reported included oncological unfavourable evolution (n=2) [14], PDE5 inhibitors use (n=11) [16,30], withdrawn consent (n=19) [11,14,21] and death due to unrelated causes [32].…”

A unified strategy to focal brachytherapy incorporating transperineal biopsy, image fusion, and real-time implantation with and without rectal spacer simulated in prostate phantoms

“…A clinical pilot study by Langley and co-authors suggested that treatment-related toxicity and biochemical outcomes after hemi-gland implants were comparable with whole glands: sexual potency was preserved in 73% and 67% of hemi- and whole gland groups, respectively ( p = 0.84). Treatment relapses in both the groups were observed as 3% [ 21 ]. Cosset et al .…”

“…Only minimal acute toxicity was observed, but no data of long-term tox-icity was available [22]. Studies of Langley et al [21] and Cosset et al [22] used traditional prescription doses of 145 Gy. However, radiation doses equal to or above a BED of 200 Gy have demonstrated improved outcomes, Stone and others have published long-term data on biopsy results, which demonstrated that a biological equivalent dose (BED) of 220 Gy (using an α/β of 2) can result in a negative biopsy rate of 98.4% [23,24].…”