Ano-rectal wall dose-surface maps localize the dosimetric benefit of hydrogel rectum spacers in prostate cancer radiotherapy
| Autor: | Ben G. L. Vanneste, Aswin L. Hoffmann, Florian Buettner, Michael Pinkawa, Philippe Lambin |
|---|---|
| Přispěvatelé: | RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy, Radiotherapie, Promovendi ODB, Precision Medicine |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
medicine.medical_treatment
MODULATED RADIATION-THERAPY Brachytherapy CONFORMAL RADIOTHERAPY R895-920 Rectum HISTOGRAMS Dose constraints Dose-surface maps BALLOON Article 030218 nuclear medicine & medical imaging Rectum spacer POLYETHYLENE-GLYCOL HYDROGEL 03 medical and health sciences Prostate cancer Medical physics. Medical radiology. Nuclear medicine 0302 clinical medicine QUALITY-OF-LIFE medicine Radiology Nuclear Medicine and imaging RC254-282 Radiotherapy business.industry BRACHYTHERAPY Toxicity reduction Neoplasms. Tumors. Oncology. Including cancer and carcinogens medicine.disease 3. Good health Radiation therapy REDUCTION medicine.anatomical_structure Oncology Rectal wall 030220 oncology & carcinogenesis GASTROINTESTINAL TOXICITY Sphincter TRIAL business Complication Nuclear medicine |
| Zdroj: | Clinical and Translational Radiation Oncology, Vol 14, Iss, Pp 17-24 (2019) Clinical and Translational Radiation Oncology 14(2019), 17-24 Clinical and Translational Radiation Oncology, 14, 17-24. Elsevier Ireland Ltd Clinical and Translational Radiation Oncology |
| ISSN: | 2405-6308 |
| Popis: | Highlights • Implantable rectum spacers (IRS) separate the ano-rectal wall (ARW) from the prostate. • Dose-surface maps (DSMs) are a tool to take spatio-dosimetric info into account. • Spatio-dosimetric differences in ARW DSMs exist comparing IMRT with and without IRS. • IRS reduces the lateral and longitudinal extent of areas >50 Gy. • IRS reduces these high-dose areas in anterior and superior-inferior directions. Background and purpose To evaluate spatial differences in dose distributions of the ano-rectal wall (ARW) using dose-surface maps (DSMs) between prostate cancer patients receiving intensity-modulated radiation therapy with and without implantable rectum spacer (IMRT+IRS; IMRT−IRS, respectively), and to correlate this with late gastro-intestinal (GI) toxicities using validated spatial and non-spatial normal-tissue complication probability (NTCP) models. Materials and methods For 26 patients DSMs of the ARW were generated. From the DSMs various shape-based dose measures were calculated at different dose levels: lateral extent, longitudinal extent, and eccentricity. The contiguity of the ARW dose distribution was assessed by the contiguous-DSH (cDSH). Predicted complication rates between IMRT+IRS and IMRT−IRS plans were assessed using a spatial NTCP model and compared against a non-spatial NTCP model. Results Dose surface maps are generated for prostate radiotherapy using an IRS. Lateral extent, longitudinal extent and cDSH were significantly lower in IMRT+IRS than for IMRT−IRS at high-dose levels. Largest significant differences were observed for cDSH at dose levels >50 Gy, followed by lateral extent at doses >57 Gy, and longitudinal extent in anterior and superior-inferior directions. Significant decreases (p = 0.01) in median rectal and anal NTCPs (respectively, Gr 2 late rectal bleeding and subjective sphincter control) were predicted when using an IRS. Conclusions Local-dose effects are predicted to be significantly reduced by an IRS. The spatial NTCP model predicts a significant decrease in Gr 2 late rectal bleeding and subjective sphincter control. Dose constraints can be improved for current clinical treatment planning. |
| Databáze: | OpenAIRE |
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