Purpose: Intraoperative radiation therapy (IORT) allows delivery of tumoricidal doses of radiation to areas of potential residual microscopic disease while minimizing doses to normal tissues. IORT using high-dose-rate (HDR) brachytherapy allows dose modulation and delivery of concomitant boosts to high-risk areas. This study describes a novel technique of HDR-IORT with dose painting (DP) (HDR-IORT-DP) and evaluates the clinical outcomes.
Methods And Materials: Sixteen patients with recurrent cancers received HDR-IORT-DP at the time of radical resection. Of these patients, 13 had colorectal cancer, 2 had head and neck cancer, and 1 had a gynecologic malignancy. All received external beam radiation previously. Negative margin (R0) was obtained in 12 patients (75%) and microscopically positive margins (R1) in 4 patients (25%).
Results: The median total target and boost area were 45 and 8.5cm(2), and HDR-IORT and boost dose were 1500 and 1750cGy, respectively. Median followup was 14.9 months. The 2-year local control and overall survival were 80% and 20%, respectively. Eleven patients (69%) developed distant metastasis and were deceased at the time of the last followup. A total of 13 patients (19%) developed Grade 3 toxicity related to HDR-IORT; no grade 4+ toxicities were observed.
Conclusions: HDR-IORT-DP technique is feasible, safe, and allows for dose escalation in locally advanced or recurrent previously irradiated tumors. To our knowledge, this is the first clinical report on HDR-IORT-DP. Further studies are warranted to evaluate efficacy in a larger patient cohort. Local control was encouraging in our patients.
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http://dx.doi.org/10.1016/j.brachy.2012.04.011 | DOI Listing |
Med Phys
January 2025
Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.
Background: A stemless plastic scintillation detector (SPSD) is composed of an organic plastic scintillator coupled to an organic photodiode. Previous research has shown that SPSDs are ideally suited to challenging dosimetry measurements such as output factors and profiles in small fields. Lacking from the current literature is a systematic effort to optimize the performance of the photodiode component of the detector.
View Article and Find Full Text PDFRadiother Oncol
December 2024
Section for Biomedical Physics, Department of Radiation Oncology, University of Tübingen, Tübingen, Germany; German Cancer Consortium (DKTK), partner site Tübingen, and German Cancer Research Center (DKFZ), Heidelberg, Germany; Cluster of Excellence "Machine Learning", University of Tübingen, Tübingen, Germany. Electronic address:
Purpose: To retrain a model based on a previously identified prognostic imaging biomarker using apparent diffusion coefficient (ADC) values from diffusion-weighted magnetic resonance imaging (DW-MRI) in a preclinical setting and validate the model using clinical DW-MRI data of patients with locally advanced head-and-neck cancer (HNC) acquired before radiochemotherapy.
Material And Methods: A total of 31 HNC patients underwent T2-weighted and DW-MRI using 3 T MRI before radiochemotherapy (35 x 2 Gy). Gross tumor volumes (GTV) were delineated based on T2-weighted and b500 images.
J Appl Clin Med Phys
December 2024
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
Tumor hypoxia significantly impacts the efficacy of radiotherapy. Recent developments in the technique of dose painting by numbers (DPBN) promise to improve the tumor control probability (TCP) in conventional radiotherapy for hypoxic cancer. The study initially combined the DPBN method with hypoxia-guided dose distribution optimization to overcome hypoxia for lung cancers and evaluated the effectiveness and appropriateness for clinical use of the DPBN plans.
View Article and Find Full Text PDFArch Toxicol
November 2024
Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestraße 9-11, 91054, Erlangen, Germany.
UV-P (2-(2H-Benzotriazol-2-yl)-p-cresol) is used as an ultraviolet (UV) light absorber in coating products, paints, adhesives, and sealants. Due to its widespread industrial and consumer uses, human exposure to UV-P is conceivable. In the study presented herein, initial data on its human in vivo metabolism were obtained for three study participants after single oral administration of 0.
View Article and Find Full Text PDFPharmaceuticals (Basel)
October 2024
Department of Silviculture, Forestry and Game Management Research Institute, Na Olivě 550, 517 73 Opočno, Czech Republic.
Zinc oxide nanoparticles are safe, non-toxic, and biocompatible. These NPs are used in food packaging materials, self-cleaning glass, ceramics, deodorants, sunscreens, paints, coatings, ointments, lotions, and as preservatives. This study explored the biological potential of ZnO nanoparticles synthesized using .
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