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CT perfusion imaging in response assessment of pulmonary metastases undergoing stereotactic ablative radiotherapy
Author(s) -
Sawyer Brooke,
Pun Emma,
Samuel Michael,
Tay Huilee,
Kron Tomas,
Bressel Mathias,
Ball David,
Siva Shankar
Publication year - 2015
Publication title -
journal of medical imaging and radiation oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.31
H-Index - 43
eISSN - 1754-9485
pISSN - 1754-9477
DOI - 10.1111/1754-9485.12272
Subject(s) - medicine , sabr volatility model , perfusion , nuclear medicine , radiology , perfusion scanning , ablative case , radiosurgery , intraclass correlation , radiation therapy , volatility (finance) , clinical psychology , psychometrics , stochastic volatility , financial economics , economics
Stereotactic ablative body radiotherapy ( SABR ) is an emerging treatment technique for pulmonary metastases in which conventional R esponse E valuation C riteria in S olid T umours ( RECIST ) may be inadequate. This study aims to assess the utility of CT perfusion imaging in response assessment of pulmonary metastases after SABR . Methods In this ethics board‐approved prospective study, 11 patients underwent a 26‐Gy single fraction of SABR to pulmonary metastases. CT perfusion imaging occurred prior to and at 14 and 70 days post‐ SABR . Blood flow (mL/100 mL/min), blood volume (mL/100 mL), time to peak (seconds) and surface permeability (mL/100 mL/min), perfusion parameters of pulmonary metastases undergoing SABR , were independently assessed by two radiologists. Inter‐observer variability was analysed. CT perfusion results were analysed for early response assessment comparing day 14 with baseline scans and for late response by comparing day 70 with baseline scans. The largest diameter of the pulmonary metastases undergoing SABR was recorded. Results Ten patients completed all three scans and one patient had baseline and early response assessment CT perfusion scans only. There was strong level of inter‐observer agreement of CT perfusion interpretation with a median intraclass coefficient of 0.87 (range 0.20–0.98). Changes in all four perfusion parameters and tumour sizes were not statistically significant. Conclusion CT perfusion imaging of pulmonary metastases is a highly reproducible imaging technique that may provide additional response assessment information above that of conventional RECIST , and it warrants further study in a larger cohort of patients undergoing SABR .