ORLANDO—A novel prostate brachytherapy technique that avoids the central zone may sharply reduce periurethral prostate radiation (XBT) and significantly reduce posttreatment urinary obstruction/irritation. In addition, this approach may significantly reduce long-term urinary incontinence, according to a prospective study presented at the Genitourinary Cancers Symposium.
“We wanted to investigate whether a brachytherapy plan that avoids the central zone and the transition zone can minimize urinary toxicity and perhaps most importantly long-term urinary incontinence,” said lead study investigator James Talcott, MD, associate professor of medicine at Massachusetts General Hospital, Boston. “We followed the patients for 5 years and we found that by avoiding the central zone you are able to decrease the acute urinary obstruction/irritation, and it resolves about a year or two earlier.”
Talcott said these findings may be of particular interest to oncology nurses because the results suggest that this type of brachytherapy can be used at any institution and help lower morbidity associated with prostate brachytherapy.
The investigators compared urinary outcomes of patients who received sharply reduced XBT with outcomes of patients treated with standard brachytherapy techniques (SBT). They surveryed newly diagnosed, untreated patients with clinically localized prostate cancer before brachytherapy.
Talcott and his colleagues gathered demographic information as well as clinical and quality-of-life information. They also conducted follow-up interviews at 1, 3, 12, 24, 36, 48, and 60 months posttreatment. A total of 263 patients were enrolled in the study. The XBT patients tended to be slightly younger and reported more baseline urinary obstruction/irritation, but the treatment groups were otherwise similar before treatment.
The investigators found that urinary obstruction/irritation was increased for 24 months in both treatment groups. However, the XBT patients reported lower increases and their problems with urinary obstruction/irritation resolved earlier. Talcott said overall urinary incontinence appeared to rise at 60 months after SBT but not XBT. He said of the patients who reported complete pretreatment urinary control, 33% of SBT compared with 15% of XBT patients reported some incontinence.
“The other interesting thing we found was that sexual dysfunction appears to increase for 5 years,” said Talcott in an interview with The Oncology Nurse-APN/NP. “Most of the data I have seen indicate that sexual dysfunction appears to be less of a problem with brachytherapy alone compared with other modalities (external beam radiotherapy and surgery). However, it may be that it is developing a little later. There appears to be an ongoing increase in sexual dysfunction, which tells me the question remains open.”
He said the findings suggest that after 3 years the problem of urinary obstruction/irritation goes away with XBT. However, urinary incontinence may be a late complication and more studies are needed to evaluate how prevalent this side effect is long term. Talcott said that oncology nurses now have data they can share with their patients when it comes to educating them about sexual dysfunction after brachytherapy that avoids the central zone.
“The take-home message [for patients] is that urinary obstruction/irritation is part of the territory, as they know, but they don’t have to worry about it long term (with XBT). In terms of sexual dysfunction at 3 years, which is usually defined as long term, that is not long enough. [Patients] are probably going to get greater sexual dysfunction after 3 years,” said Talcott. “We didn’t know this until now.”