Conventional dose rate spatially-fractionated radiation therapy (SFRT) treatment response and its association with dosimetric parameters-A preclinical study in a Fischer 344 rat model

Autor: Anthony S. Abrantes, Judith N. Rivera, Paul A. Dayton, Thomas M. Kierski, Sha Chang, Sandeep K. Kasoji
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Topography
Physiology
Fibrosarcoma
medicine.medical_treatment
Cancer Treatment
Toxicology
Pathology and Laboratory Medicine
Diagnostic Radiology
030218 nuclear medicine & medical imaging
Mathematical and Statistical Techniques
0302 clinical medicine
Ultrasound Imaging
Medicine and Health Sciences
Medicine
Fractionation
Multidisciplinary
Radiology and Imaging
Statistics
Tumor Burden
Separation Processes
Treatment Outcome
Oncology
Physiological Parameters
030220 oncology & carcinogenesis
Physical Sciences
Toxicity
Regression Analysis
Female
Research Article
Valleys
Clinical Oncology
Treatment response
Imaging Techniques
Science
Rat model
Radiation Therapy
Linear Regression Analysis
Research and Analysis Methods
03 medical and health sciences
Diagnostic Medicine
Linear regression
Animals
Irradiation
Statistical Methods
Radiometry
Fractionated radiation
Landforms
business.industry
Proportional hazards model
Body Weight
Dose fractionation
Biology and Life Sciences
Geomorphology
Rats
Inbred F344
Rats
Radiation therapy
Disease Models
Animal
Earth Sciences
Dose Fractionation
Radiation
Clinical Medicine
Nuclear medicine
business
Dose rate
Mathematics
Zdroj: PLoS ONE, Vol 15, Iss 6, p e0229053 (2020)
PLoS ONE
ISSN: 1932-6203
Popis: PurposeTo identify key dosimetric parameters that have close associations with tumor treatment response and body weight change in SFRT treatments with a large range of spatial-fractionation scale at dose rates of several Gy/min.MethodsSix study arms using uniform tumor radiation, half-tumor radiation, 2mm beam array radiation, 0.3mm minibeam radiation, and an untreated arm were used. All treatments were delivered on a 320kV x-ray irradiator. Forty-two female Fischer 344 rats with fibrosarcoma tumor allografts were used. Dosimetric parameters studied are peak dose and width, valley dose and width, peak-to-valley-dose-ratio, volumetric average dose, percentage volume directly irradiated, and tumor- and normal-tissue EUD. Animal survival, tumor volume change, and body weight change (indicative of treatment toxicity) are tested for association with the dosimetric parameters using linear regression and Cox Proportional Hazards models.ResultsThe dosimetric parameters most closely associated with tumor response are tumor EUD (R2=0.7923, F-stat=15.26*; z-test=−4.07***), valley/minimum dose (R2=0.7636, F-stat=12.92*; z-test=−4.338***), and percentage tumor directly irradiated (R2=0.7153, F-stat=10.05*; z-test=−3.837***) per the linear regression and Cox Proportional Hazards models, respectively. Tumor response is linearly proportional to valley/minimum doses and tumor EUD. Average dose (R2=0.2745, F-stat=1.514 (no sig.); z-test=−2.811**) and peak dose (R2=0.04472, F-stat=0.6874 (not sig.); z-test=−0.786 (not sig.)) show the weakest associations to tumor response. Only the uniform radiation arm did not gain body weight post-radiation, indicative of treatment toxicity; however, body weight change in general shows weak association with all dosimetric parameters except for valley/min dose (R2=0.3814, F-stat=13.56**), valley width (R2=0.2853, F-stat=8.783**), and peak width (R2=0.2759, F-stat=8.382**).ConclusionsFor a single-fraction SFRT at conventional dose rates, valley, not peak, dose is closely associated with tumor treatment response and thus should be used for treatment prescription. Tumor EUD, valley/min dose, and percentage tumor directly irradiated are the top three dosimetric parameters that exhibited close associations with tumor response.
Databáze: OpenAIRE
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