“Hypofractionated external beam radiation therapy (EBRT) for early prostate cancer represents a reasonable alternative to standard treatment protocols involving lower doses of radiation administered over a longer period of time, according to a new clinical guideline.
” ‘Moderately hypofractionated’ EBRT regimens result in similar disease control and side effects as compared with conventional protocols, although the shortened regimens confer a small risk of more short-term gastrointestinal toxicity. Additionally, physicians should counsel patients about the limited data on oncologic outcomes beyond 5 years of follow-up, according to a panel representing the American Society for Radiation Oncology, American Society of Clinical Oncology, and American Urological Association.”
“The addition of external-beam radiotherapy (EBRT) to interstitial brachytherapy failed to reduce prostate cancer progression compared to brachytherapy alone in men with intermediate-risk disease, interim data from a randomized trial showed.
“The 5-year freedom from progression was 84.5% with combined-modality radiotherapy and 85.6% with prostate brachytherapy alone. The odds ratio (OR) for brachytherapy versus combined radiotherapy was 1.09 after a median follow-up of 7.7 years, a difference that did not achieve statistical significance for efficacy or meet the prespecified statistical value to stop the trial for futility.”
“Low-dose brachytherapy boosts held prostate cancer in check significantly better than dose-escalated external-beam radiation therapy (EBRT) in men with unfavorable-risk disease, a randomized trial showed.
“Patients treated with brachytherapy after androgen deprivation therapy (ADT) and whole-pelvis EBRT had an estimated 9-year relapse-free survival (RFS) of 83% compared with 63% for patients who received a conformal EBRT boost. The difference in favor of brachytherapy emerged after 5 years of follow-up, Scott Tyldesley, MD, of the British Columbia Cancer Agency in Vancouver, reported here at the Genitourinary Cancers Symposium.
” ‘In the context of 12 months of androgen deprivation therapy and whole pelvis external beam radiotherapy, treatment with a low-dose pelvic brachytherapy boost results in a 50% reduction in biochemical relapse compared to dose-escalated EBRT to 78 Gray,’ Tyldesley said. ‘At 6.5 years of follow-up, there was no difference in overall survival, prostate cancer specific survival, or metastasis-free survival.’
“However, ‘there was increased late grade 3 or higher GU toxicity with the low-dose rate boost, a 5% to 6% increase in the prevalence of late GU toxicity,’ he said.”
The gist: A recent scientific study showed that radiation therapy that avoids damaging tissue next to a prostate tumor can be effective and preserve long-term sexual function.
“A comparison of five-year sexual function outcomes, as reported by patients treated with external beam radiotherapy (EBRT) versus combination EBRT plus brachytherapy, indicates that the utilization of vessel-sparing radiation therapy makes cure possible without compromising long-term sexual function, according to research presented today at the American Society for Radiation Oncology’s (ASTRO’s) 56th Annual Meeting.
“The study examined the patient-reported outcomes of 91 men with prostate cancer who received MRI-guided, vessel-sparing radiation at University of Michigan Providence Cancer Institute. The vessel-sparing radiation technique limits the amount of radiation to critical erectile tissues using MRI scans to identify the blood vessels responsible for erections. When radiation dose is limited to these critical structures, the risk of erectile dysfunction is lowered.
“Of the 91 patients studied, all patients received EBRT. Forty-two of the patients received only EBRT (>77.8Gy), and 49 patients received EBRT plus brachytherapy, the implantation of radioactive seeds near the prostate. The combination patients received brachytherapy in the form of an I-125 permanent prostate implant. None of the patients received androgen deprivation therapy (ADT)…
“ ‘In the past, men with prostate cancer expected to pay a high toll in loss of quality of life to achieve cure and were willing to accept that as necessary,’ said lead study author Patrick W. McLaughlin, MD, director of radiation oncology at University of Michigan Providence Cancer Institute in Novi, Mich. ‘This study makes it clear that even with combination radiation protocols, which are capable of curing the majority of prostate cancers more than 90 percent of the time, avoidance of critical adjacent tissues, such as vessel-sparing, makes cure and quality of life an achievable goal for many men.’ ”
“Combined brachytherapy and external beam therapy (EBRT) is associated with a high rate of five-year biochemical failure-free survival in men with high-risk prostate cancer (PCa), according to a Japanese study. The study included 206 patients with high-risk PCa treated with iodine-125 brachytherapy and EBRT. Of these, 101 (49%) also received neoadjuvant androgen deprivation therapy (ADT), but no patient received adjuvant ADT. The patients had a median follow-up of 60 months.”