Prostate Cancer

Prostate cancer is the second most common cancer in men worldwide. Screening for prostate-specific antigen (P.S.A.) levels have led to prostate cancer being increasingly diagnosed.
Common symptoms of prostate cancer are difficulty urinating, reduced stream of urine, blood in the semen, erectile dysfunction and discomfort in the pelvic area.

The initial treatment options for patients with non-metastatic prostate cancer (cancer that has not spread beyond the primary site to other areas in the body) consists of active surveillance, radical prostatectomy and radiotherapy. The choice of treatment is determined by clinical staging (progression of disease), the P.S.A. level, Gleason score, patient preference, life expectancy, patient functional status and resource availability1-3.

What is Prostate Brachytherapy?

Prostate brachytherapy is a form of internal radiation therapy used to treat prostate cancer. It’s an established and effective cancer treatment, and involves placing temporary or permanent radioactive sources into the prostate tissue. This allows high doses of radiation to be delivered to the cancer cells, within the prostate gland, whilst reducing radiation of normal tissues.
A major advantage of brachytherapy is that it can be completed within 1-2 days with little time lost from normal activities. Depending on the risk category of the patient, it can be used alone or in combination with external beam radiotherapy. New developments in prostate brachytherapy include its use in salvage treatment, following relapse in patients who received prior radiotherapy and as a boost to permit dose escalation 2;4.

How is it performed?

The patient undergoes general or spinal anaesthesia. Radiation sources are then placed in the prostate under rectal ultrasound guidance. Low-dose rate brachytherapy (L.D.R.) is delivered through a vessel known as ‘’seeds’’ and is permanent; whilst high-dose rate brachytherapy (HDR) is delivered with hollow catheters and is temporary.

What are the side effects?

Anatomically the prostate gland is close to the urethra, bladder and rectum. These structures can develop acute and late side effects from prostate brachytherapy. Most commonly, there can be worsening of urinary symptoms, such as increased frequency, nocturia (frequent urination at night), urination hesitancy, urgency or a weak urinary stream and urinary retention. Uncommon complications are urethral strictures, rectal bleeding, rectal fistulas and erectile dysfunction 2;5.

Which patients should not have bracytherapy?
Patients with the following considerations may not be recommended for this type of treatment:
• Limited lifespan
• Unacceptable operative risks
• International prostate symptom score (IPSS) score >20
• Transurethral resection of the prostate (TURP) within 3-6 months
• Rectal fistula
• Pubic arch interference

What can be expected after the procedure?
Patients may experience mild discomfort and swelling in the perineum where the needles were placed. Ice packs and analgesia may be used for alleviation of discomfort. Patients should avoid strenuous activities that may irritate the perineum, like bike riding and running. Follow-up PSA testing will be ordered by your radiation oncologist.

The take home message:

Prostate brachytherapy is a cost effective, convenient radiation technique with excellent oncologic outcomes that is recommended for the curative treatment of men with prostate cancer.

Author: Dr Nirsha Chiranjan - Radiation Oncologist at DMO.

REFERENCES
1. National Comprehensive Cancer Network (NCCN). NCCN Clinical practice guidelines in oncology.
2. THE GEC ESTRO HANDBOOK OF BRACHYTHERAPY
3. Bekelman JE, Rumble RB, Chen RC, et al. Clinically Localized Prostate Cancer: ASCO Clinical Practice Guideline Endorsement of an American Urological Association/American Society for Radiation Oncology/Society of Urologic Oncology Guideline. J. Clin Oncol 2018; :JCO1800606.
4. Chin J, Rumble RB, Kollmeier M, et al. Brachytherapy for patients with prostate cancer: American Society of Clinical Oncology/Cancer Care Ontario joint guideline update. J Clin Oncol 2017.
5. Keyes M, Miller S, Moravan V, et al. Predictive factors for acute and late urinary toxicity after permanent prostate brachytherapy: long-term outcome in 712 consecutive patients. Int J Radiat Oncol Biol Phys 2009; 73:1023.