Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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The two main modalities to deliver high dose to the prostate and prevent high doses to neighboring organs are intensity modulated radiotherapy (IMRT) or external beam radiotherapy combined with brachytherapy. Because of the different biological effectiveness the physical dose distributions were converted to 3-dimensional linear quadratic dose at 2 Gy per fraction (EQD(2)). From the latter, cumulative EQD(2)-volume histograms were determined for comparison of the modalities. ⋯ Because of the high doses within an implant, the dose in 50% of the prostate volume is much higher with the brachytherapy modalities than IMRT-only which may have clinical consequences. With brachytherapy the doses to the OAR are lower or similar to IMRT-only. Dose escalation for prostate tumors is more easily achieved with brachytherapy than with IMRT alone. Therefore, brachytherapy might be the preferred modality to achieve further dose escalation.
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The aim of the study was to analyze health-related quality of life changes after postoperative radiotherapy (RT) for prostate cancer. ⋯ In contrast to bowel symptoms, acute urinary problems recover very soon after the end of postoperative RT. After >1 year, only minor HRQOL changes occurred in comparison to baseline scores.
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To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. ⋯ Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes.
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Lower urinary tract symptoms are frequently observed after I-125 seed implantation of the prostate. More knowledge about causes and predictors is necessary to be able to develop less toxic implantation techniques. The aim of this study was to identify implantation related factors that contribute to post-implant urinary morbidity. ⋯ Bladder hotspot dose appears to be an important dosimetric predictor for urinary morbidity both at 3 months and at 6 months after implantation. Other predictors are prostate volume, or equivalently, the number of implanted seeds.