Permanent interstitial low-dose-rate brachytherapy for patients with localised prostate cancer: a systematic review of randomised and nonrandomised controlled clinical trials.

CONTEXT

Prostate cancer (PCa) is the most common cancer in men. Permanent interstitial low-dose-rate brachytherapy (LDR-BT) is a short-distance radiation therapy in which low-energy radioactive sources are implanted permanently into the prostate.

OBJECTIVE

To assess the effectiveness and safety of LDR-BT compared to treatment alternatives in men with localised PCa.

EVIDENCE ACQUISITION

Bibliographic databases (Medline, Embase, and the Cochrane Library) were searched from inception until June 2010 for randomised and nonrandomised controlled trials comparing LDR-BT with radical prostatectomy (RP), external-beam radiation therapy (EBRT), or no primary therapy (NPT). Primary outcome was overall survival (OS). Secondary outcomes were disease-free survival (DFS), biochemical recurrence-free survival (bRFS), physician-reported severe adverse events (SAE), and patient-reported outcomes (PRO).

EVIDENCE SYNTHESIS

A total of 31 studies, including 1 randomised controlled trial (RCT), were identified. Risk of bias was high for all 31 studies. OS was reported in one nonrandomised controlled study; however, these data were not interpretable because of strong residual confounding. DFS was not reported. Comparison of bRFS between treatment groups is not validated; thus, results were not interpretable. Physician-reported urogenital late toxicity grade 2 to 3 was more common in the LDR-BT group when compared to the EBRT group. With respect to PRO, better scores for sexual and urinary function as well as urinary incontinence were reported for LDR-BT compared to RP. Better scores for bowel function were reported for LDR-BT compared to EBRT.

CONCLUSIONS

We found a low amount of evidence in studies that exclusively compared LDR-BT with other treatment modalities. LDR-BT may have some different physician-reported SAE and patient-reported outcomes. The current evidence is insufficient to allow a definitive conclusion about OS. Randomised trials focusing on long-term survival are needed to clarify the relevance of LDR-BT in patients with localised PCa.