BERKELEY, CA (UroToday.com) - Brachytherapy is a form of internal radiotherapy, by which the prostate affected with a malignant tumor is treated with a radioactive source. The advantage of brachytherapy compared to external beam radiotherapy is that the prostate can be treated from inside out, without causing too much harm to the surrounding healthy tissues. In the operating room, multiple perineal catheters are placed in the prostate to enable the radioactive source to enter the gland. The placement of these catheters enables local treatment, with minimal dose to the organs at risk. However, it is still common practice to treat the whole prostate gland because prostate cancer is often a multi focal disease. Another reason to treat the whole gland is because it is still hard to identify the malignant foci for treatment with the available imaging techniques.
Recently the call for identification of the tumor lesions has grown, allowing for more targeted therapy of the prostate cancer. Brachytherapy can be used as a focal treatment in early disease or as a means of intensifying the treatment for more advanced disease. In early-disease patients with PSA < 15 ng/ml and Gleason 6-7, focal treatment might be a good alternative for those patients who do not accept active surveillance. A partial treatment of a part of the prostate, or even only the index lesions, might reduce the toxicity in these patients. In 20 to 30% of the patients with stage II or III prostate cancers, relapses occur primarily in the primary tumor region. These patients might benefit from a local dose escalation with brachytherapy.
In our study, we performed a preliminary research on the applicability of contrast-enhanced ultrasound with hexafluoride micro-bubbles to detect tumor lesions within the prostate. This is a promising technique in brachytherapy of the prostate, because for most hospitals, ultrasound is still the only imaging modality available in the operating room. Although, in this study, a fusion was necessary for the contrast-enhanced ultrasound and the ultrasound made in the operating room, the technique is also immediately applicable to the ultrasound made in the operating room. By making the tumor lesions visible on ultrasound imaging in the operating room, the catheter placement can be adopted in such a way as to enable further treatment modulation in relation to the visible tumor lesions. This study shows that using CEUS optimization of a brachytherapy plan, to the target volume, is possible without increasing dose to the organs at risk.
Written by:
Bradley Pieters, MD, PhD, Hessel Wijkstra, PhD, Marcel van Herk, PhD, Ruud Kuipers, Emmie Kaljouw, MSc, Jean de la Rosette, MD, PhD, and Caro Koning, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Radiotherapy Department, Academic Medical Center/University of Amsterdam, Amsterdam, The Netherlands
Contrast-enhanced ultrasound (CEUS) as support for prostate brachytherapy treatment planning - Abstract
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