Hatef Mehrabian1, Kimberly L Desmond2, Sofia Chavez3, Colleen Bailey4, Radoslaw Rola5, Arjun Sahgal6, Gregory J Czarnota7, Hany Soliman8, Anne L Martel9, Greg J Stanisz10. 1. Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada. Electronic address: hatef.mehrabian@sri.utoronto.ca. 2. Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada. 3. Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada. 4. Computer Science Department, University College London, London, United Kingdom. 5. Neurosurgery and Pediatric Neurosurgery, Medical University, Lublin, Poland. 6. Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. 7. Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. 8. Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. 9. Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada. 10. Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Neurosurgery and Pediatric Neurosurgery, Medical University, Lublin, Poland.
Abstract
PURPOSE: This study was designed to evaluate whether changes in metastatic brain tumors after stereotactic radiosurgery (SRS) can be seen with quantitative MRI early after treatment. METHODS AND MATERIALS: Using contrast-enhanced MRI, a 3-water-compartment tissue model consisting of intracellular (I), extracellular-extravascular (E), and vascular (V) compartments was used to assess the intra-extracellular water exchange rate constant (kIE), efflux rate constant (kep), and water compartment volume fractions (M0,I, M0,E, M0,V). In this prospective study, 19 patients were MRI-scanned before treatment and 1 week and 1 month after SRS. The change in model parameters between the pretreatment and 1-week posttreatment scans was correlated to the change in tumor volume between pretreatment and 1-month posttreatment scans. RESULTS: At 1 week kIE differentiated (P<.001) tumors that had partial response from tumors with stable and progressive disease, and a high correlation (R=-0.76, P<.001) was observed between early changes in the kIE and tumor volume change 1 month after treatment. Other model parameters had lower correlation (M0,E) or no correlation (kep, M0,V). CONCLUSIONS: This is the first study that measured kIE early after SRS, and it found that early changes in kIE (1 week after treatment) highly correlated with long-term tumor response and could predict the extent of tumor shrinkage at 1 month after SRS.
PURPOSE: This study was designed to evaluate whether changes in metastatic brain tumors after stereotactic radiosurgery (SRS) can be seen with quantitative MRI early after treatment. METHODS AND MATERIALS: Using contrast-enhanced MRI, a 3-water-compartment tissue model consisting of intracellular (I), extracellular-extravascular (E), and vascular (V) compartments was used to assess the intra-extracellular water exchange rate constant (kIE), efflux rate constant (kep), and water compartment volume fractions (M0,I, M0,E, M0,V). In this prospective study, 19 patients were MRI-scanned before treatment and 1 week and 1 month after SRS. The change in model parameters between the pretreatment and 1-week posttreatment scans was correlated to the change in tumor volume between pretreatment and 1-month posttreatment scans. RESULTS: At 1 week kIE differentiated (P<.001) tumors that had partial response from tumors with stable and progressive disease, and a high correlation (R=-0.76, P<.001) was observed between early changes in the kIE and tumor volume change 1 month after treatment. Other model parameters had lower correlation (M0,E) or no correlation (kep, M0,V). CONCLUSIONS: This is the first study that measured kIE early after SRS, and it found that early changes in kIE (1 week after treatment) highly correlated with long-term tumor response and could predict the extent of tumor shrinkage at 1 month after SRS.
Authors: John H Suh; Rupesh Kotecha; Samuel T Chao; Manmeet S Ahluwalia; Arjun Sahgal; Eric L Chang Journal: Nat Rev Clin Oncol Date: 2020-02-20 Impact factor: 66.675