Braquiterapia de baixa taxa de dose para Carcinoma da Próstata Localizado

Author:  Dr Stephen Bourne, Urologist M.B., B.S. (HONS), FRACS (UROL)

Almost 17,000 men were diagnosed with prostate cancer in 2020 and over 3,000 men die from prostate cancer each year. Effectively discussing management options for men with a new diagnosis of localised adenocarcinoma of the prostate requires time. It is important these men and their families are fully informed of the advantages and disadvantages of all available treatment options prior to making a decision.

In patients not suitable for an active surveillance approach, treatment options for localised prostate cancer include external beam radiation therapy, surgery and brachytherapy. The emerging focal therapy options are best delivered within the setting of a clinical trial.

While these treatments have comparable long-term survival outcomes, they may differ in side effect profile, quality of life impact, time and cost. However, radiation continues to be underutilised in the treatment of prostate cancer in Australia, particularly in the private sector.

Low dose rate brachytherapy

Low-dose rate (LDR) brachytherapy has been an available treatment option for many years. There have been significant improvements in patient selection and delivery methods for the implant, which have offered improved patient outcomes. Patient selection, as always, is critical. Current reimbursement criteria includes prostate-specific antigen (PSA) < 10, Gleason score of ≤7 and clinical T1/T2 disease.

The treatment involves the implantation of radioactive seeds into the prostate via the transperineal route, under transrectal ultrasound guidance. Patients have a catheter for a few hours post-implant and are discharged the following day or may be treated on a day-case basis. They can often return to normal activities within one to two days, making it an attractive option for many men with localised disease.

An important consideration in a patient’s suitability for LDR-brachytherapy is the volume of disease and the extent of Gleason 4 prostate cancer on the biopsy. Prostate size is another determining factor, with very small glands or glands > 50cc often difficult to implant. Contra-indications for this therapy include significant lower urinary tract symptoms, a prior transurethral resection of the prostate (TURP), significant middle lobe extension, and a previous history of bladder cancer.

Significantly, morbidity from the procedure is very low, with rapid return to normal activity and early minor risks, including haematoma, haematuria or a urinary tract infection, being quite rare. Many men develop irritative urinary symptoms (frequency, urgency or dysuria) that are usually self-limiting, peaking at around three to six months. Major risks following LDR-brachytherapy include the development of urinary retention, however this can be avoided with careful patient. A recto-prostatic fistula is a rare but potentially significant complication, which may follow inadvertent rectal biopsy at colonoscopy.

Risk of urinary incontinence and erectile dysfunction following LDR-brachytherapy is extremely low, with around 99% of men remaining continent, and potent men generally retaining their baseline erectile function. Furthermore, the risk of radiation proctitis is very low compared to other radiation treatment options.

Long-term PSA follow-up is required following treatment with LDR-brachytherapy. It can take several years to reach baseline, with an early rise possibly representing a PSA bounce (seen in up 30% of men around eighteen months post-implant), which subsequently falls again to reach a nadir.

LDR-brachytherapy offers excellent long-term results that are comparable to all alternative treatment options. Long-term biochemical control has been shown to be similar to surgery with follow-up beyond ten years in multiple studies. While localised recurrence remains a significant management dilemma, focal re-implantation is emerging as a viable alternative in select patients.

In summary, LDR brachytherapy is an attractive treatment option for men with localised prostate cancer. It offers excellent long-term results with high-quality of life outcomes particularly with respect to continence and potency, and should be discussed as an option with all suitable patients before a treatment decision is made.

About Dr Stephen Bourne

Dr Stephen Bourne, MB BS FRACS (UROL)John Flynn Private Hospital, Urology

Dr Bourne was one of the first Urologists in Queensland to establish Brachytherapy treatment for prostate cancer at Greenslopes Private Hospital and the first and currently the only one to offer this treatment at the John Flynn Private Hospital Gold Coast. Dr Bourne established his private practice in 2000 providing a comprehensive range of urological services at the John Flynn Private Hospital and the Tweed Heads and Murwillumbah District Hospital. Dr Bourne also provides education and training to the urological registrars at the Tweed Heads and Murwillumbah District Hospital.