A majority of patients receiving radical radiation therapy are treated with 1.8-2.0-Gy fractions, a dose that has evolved from clinical experience. However, other fractionation schemes can be advantageous. When fractionation is altered, the total dose prescribed should lead to equivalent or higher tumor control with the same or less tissue toxicity. To facilitate the use of different fractionation schemes, the authors compiled tables for equivalent biologic doses for late toxicity in normal tissues and tumoricidal doses for epithelial tumors, for various fraction sizes. The linear quadratic model according to Fowler was used. It is shown how these tables should be modified for proliferation of tumors during the course of radiation therapy. The tables make the use of different fractionation schemes easy. They also allow adjustment of total dose if fractionation needs to be changed during the course of treatment.
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http://dx.doi.org/10.1148/radiology.179.2.2014314 | DOI Listing |
Int J Radiat Oncol Biol Phys
January 2025
Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Purpose: Randomized trials have demonstrated similar local tumor control in patients treated with accelerated partial-breast irradiation (APBI) compared with whole-breast irradiation. However, the optimal APBI dose for maximizing tumor control and minimizing toxicity is uncertain.
Methods And Materials: We enrolled patients ≥18 years of age with grade 1 or 2 ductal carcinoma in situ or stage I invasive breast cancer and resection margins ≥2 mm between 2003 and 2011 to a sequential dose-escalation trial using 3-dimensional conformal external beam APBI giving twice daily 4 Gy fractions with total doses of 32 Gy, 36 Gy, and 40 Gy.
Int J Biol Macromol
January 2025
Beijing Key Laboratory of Lignocellulosic Chemistry, and Engineering Research Center of Forestry Biomass Materials and Energy, Ministry of Education, Beijing Forestry University, Beijing 100083, China. Electronic address:
Nat Commun
January 2025
Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.
Catheter-based pulmonary artery denervation (PADN) has achieved promising outcomes to treat pulmonary hypertension (PH). We herein present stereotactic body radiotherapy (SBRT) as a novel noninvasive approach for PADN. A single fraction of 15 Gy, 20 Gy or 25 Gy was delivered for PADN in a thromboxane A2 (TxA2) - induced acute PH swine model.
View Article and Find Full Text PDFNMR Biomed
February 2025
MR Methodology, Department for Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland.
The purpose of this study was to produce metabolite-specific T and concentration maps in a clinically compatible time frame. A multi-TE 2D MR spectroscopic imaging (MRSI) experiment (multi-echo single-shot MRSI [MESS-MRSI]) deployed truncated and partially sampled multi-echo trains from single scans and was combined with simultaneous multiparametric model fitting. It was tested in vivo for the brain in five healthy subjects.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands.
Background/objectives: Extracting spatial features (texture analysis) from dose distributions (dosiomics) for outcome prediction is a rapidly evolving field in radiotherapy. To account for fraction size differences, the biological effective dose (BED) is often calculated. We evaluated the impact and added value of the BED in the dosiomics prediction modelling of grade ≥ 2 late rectal bleeding (LRB) probability within 5 years after treatment in three parts.
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