Treatment Options: When Cancer Returns After Radiation
After prostate cancer is treated, patients usually undergo a blood test called PSA. PSA stands for Prostate Specific Antigen and is a simple blood test that gives a number. After treatment, that number should be low. If it starts to increase, that can be a signal of cancer coming back, also known as cancer recurrence.
Often doctors will watch a series of PSA values to identify the trend. If the PSA number continues to increase, this is called “biochemical failure,” and your doctors will investigate the cause. Sometimes doctors will order scans to see if there is cancer recurrence locally (in the prostate), or distantly (bones, other parts of the body). Treatment is different depending on where the cancer is found.
If there is high suspicion for local recurrence, your doctors may encourage a prostate biopsy to see if there is tumor identified under the microscope. If so, there are several local treatment options including cryotherapy (freezing the prostate) and prostatectomy. Some patients may choose observation.
Brachytherapy Option
What about using brachytherapy (internal radiation) on the prostate? This has not been as popular given the concern about risk of toxicity for patients who have used external beam radiation previously
However, at the American Society for Radiation Oncology (ASTRO) annual meeting in September 2017, Juanita Crook, MD, presented the initial results of a prospective trial (NRG/RTOG0526)1, which looked at the use of a brachytherapy implant in 100 patients who had biopsy-proven local recurrence more than 2.5 years after previous external beam radiation and without evidence of metastases. With a median follow up of almost 5 years, the late toxicities were considered acceptable.
More follow up is needed and the complete results will be reported with longer follow up, but this study shows that salvage brachytherapy may be another option in the treatment of recurrent prostate cancer after radiation therapy.
1 Crook JD, Zhang P, Pisansky TM et al. A Prospective Phase 2 Trial of Transperineal Ultrasound-Guided Brachyhtherapy for Locally Recurrent Prostate Cancer after External Beam Radiation Therapy (NRG/RTOG0526): Initial Report of Late Toxicity Outcome. ASTRO 2017.