Prostate – brachytherapy and cyberknife
Optimization of hypofractionated treatment for early stage prostate cancer.
Scope and outline
Research on linac-based external beam radiotherapy for prostate cancer is focused on (1) Currently, early stage prostate cancer is routinely treated with interstitial High Dose Rate (HDR) Brachytherapy as monotherapy, delivering 4 fractions of 9.5 Gy. Patients not eligible for HDR monotherapy may be treated at the robotic Cyberknife unit, also with 4 x 9.5 Gy. The investigations in this project focus on (technical) development and improvement of hypofractionated prostate treatment using HDR brachytherapy or image-guided external beam treatment with the Cyberknife. Clinical evaluation of outcomes and toxicity based on dosimetric data is an important prospective part of it.
Ultrasound-guided prostate implantation using a template and needles.
In HDR Brachytherapy, 4 fractions of 9.5 Gy are delivered within 36 hours. Prior to each fraction a lateral X-ray is made to check for displacements of the implant in caudal direction, and the position of the implant is adjusted if needed. About 25% of patients have catheter displacements of 5 mm or more before one or more fractions. The figure shows the dosimetric impact of simulated implant displacements on the target for five patients.
Highly non-coplanar Cyberknife treatment plan that mimics a HDR dose distribution. Also visible are two of the four implanted markers used for imaged-guided steering of the Cyberknife robot to correct for both inter- and intra-fraction prostate movements.
Selected publications
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Y Seppenwoolde, IKK Kolkman-Deurloo, D Sipkema, M de Langen, JO Praag, PP Jansen, BJM Heijmen. HDR prostate monotherapy - Dosimetric effects of implant deformation due to posture change between TRUS- and CT-imaging. Radiotherapy and Oncology, vol. 86(1), 114-119, 2008.
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IKK Kolkman-Deurloo, XGJ Deleye, PP Jansen, PCM Koper. Anatomy based inverse planning in HDR prostate brachytherapy. Radiotherapy and Oncology, vol.73(1), 73-77, 2004.
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G Kovács, R Pötter, T Loch, J Hammer, IKK Kolkman-Deurloo, JMCH de la Rosette, H Bertermann. GEC/ESTRO-EAU recommendations on temporary brachytherapy using stepping sources for localized prostate cancer. Radiotherapy and Oncology, vol.74(2), 137-148, 2005.
Contacts
Dr. S. Aluwini and Dr.Ir. I.K.K. Kolkman-Deurloo