ESTRO 38: High–Dose Rate Brachytherapy in Localized Prostate Cancer
A single high dose of radiation that can be delivered directly to a treatment site within a few minutes is a safe and effective technique for treating men with localized, low-risk prostate cancer, according to a study presented by Tharmalingam et al at ESTRO 38, the annual congress of the European Society for Radiotherapy & Oncology (ESTRO) (Abstract OC-0633).
The new treatment is called high–dose rate brachytherapy. Researchers say this technique could be an effective treatment that is convenient for patients and offers potential time and cost savings for hospitals. The research was presented by Hannah Tharmalingam, MRCP, a clinical research fellow at Mount Vernon Cancer Centre, Northwood, and The Christie NHS Foundation Trust.
Dr. Tharmalingam said, “Brachytherapy—where we use temporary catheters to directly treat tumors—has already proved to be a good treatment for prostate cancer, both in terms of killing the cancer cells and minimizing side effects. This usually means patients make four to six visits to the hospital for a series of lower-dose treatments. We wanted to see whether we could get similar results, but with just one high-dose treatment, saving time for the patient and the hospital.”
Study Methods
The research included 441 men with prostate cancer who were treated at one of seven UK hospitals between 2013 and 2018. Their cancers were classified, depending on how likely they were to spread, as either low-risk (n = 44), medium-risk (n = 285), or high-risk (n = 112). All were treated with a single high dose (19 Gy) of radiation; 166 men also received hormone therapy, but none had any surgery or chemotherapy.
Researchers monitored the men’s progress for an average of 26 months. They measured levels of prostate-specific antigen at 2 years after the treatment and again 3 years after the treatment.
Results
The 2-year biochemical progression-free survival rate was 96% for all patients, and 100%, 97%, and 95% for low-, intermediate-, and high-risk patients, respectively. Three-year biochemical progression-free survival rates were 88% (overall), 100% (low-risk), 90% (intermediate-risk), and 79% (high-risk; P = .1). Sites of relapse were radiologically identified in 21 of the 27 biochemical failures. Of these, 14 patients had a local prostate recurrence.
Acute grade 2 genitourinary and gastrointestinal toxicity peaked at 1 month postimplant. No grade 3 or 4 acute toxicity was reported. Two patients developed late grade 3 genitourinary toxicity, and two patients developed late grade 3 gastrointestinal toxicity.
Dr. Tharmalingam said, “These results indicate that high–dose rate brachytherapy is a safe and effective treatment for men with low-risk prostate cancer, but further research is needed in medium- and high-risk patients to see if the results can be improved with a higher dose. This type of treatment offers an attractive alternative to surgery or other forms of radiotherapy as it has a comparatively low risk of side effects. It is also a patient-friendly option, because the treatment can be given quickly at a single hospital visit.”
Dr. Tharmalingam and her colleagues hope to continue studying the impact of using this type of radiotherapy, especially in patients with higher-risk prostate cancer who are more likely to suffer a recurrence. She believes it would be possible, given the low risk of side effects, to modify the treatment or increase the dose even further in higher-risk cases.
Disclosure: For full disclosures of the study authors, visit estro.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
