Impotence and Incontinence Reduced with High Dose Rate Brachytherapy and Image-Guided Technology

High-dose rate (HDR) brachytherapy used in combination with an innovative new image-guidance technology was shown to be just as effective as conventional therapies, but much less likely to cause the common side effects of impotence and incontinence.

Conventional treatments for prostate cancer are surgery (prostatectomy) to remove the prostate, and radiotherapy. Typically, radiotherapy is delivered from an external source situated at a distance (a process known as teletherapy or external beam therapy), and is, therefore, directed over the entire prostate area. This makes it nearly impossible to avoid penetrating healthy tissue, including the sensitive urethra running through the middle of the prostate, and the neurovascular bundles (on either side at the base of the prostate) that control penile function. After surgery or conventional teletherapy, between 40-100% of men will be left impotent, and 35% of surgery patients will suffer incontinence.

In brachytherapy, on the other hand, the tumor is irradiated from the inside. In prostate cancer therapy, this is achieved by introducing small tubes into the prostate at specific points, and then inserting a radioactive isotope either temporarily (HDR) or permanently (tiny implants) into each tube to deliver the appropriate dose.

Until recently, the precision of HDR brachytherapy was determined by positioning the tubes based on computed tomography (CT) imaging. However, CT scans tend to generate indistinct images of the prostate. Furthermore, the images have to be captured after, rather than during the tube insertion, and so can prove inaccurate with respect to the position of the prostate and to other internal adjacent organs, where it may move.

A new technology to further improve the precision of HDR brachytherapy was therefore developed by a multidisciplinary team of radiation oncologists and medical physicists together with Nucletron (Veenendaal, The Netherlands), a manufacturer of radiotherapy equipment and software. The real-time image-guidance technology that they created has now made it possible to view crucial features of the procedure in real time, instead of relying on past images. This means that clinicians can view the position of the organs, check whether the tubes are following the right insertion pathways, and amend the dose to more accurately target the tumor while avoiding susceptible areas.

The outcome of the study featuring this new technology, comprising over 300 patients, was announced in June 2007 at the 12th International Conference on Optimal Use of Advanced Radiotherapy on Multimodality Oncology in Rome, Italy. The study was performed by Professors. Zamboglou, Tunn, and Baltas from the University Hospital in Offenbach, Germany.


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