This poster is a theoretical calculation of mortality risk from a BWH CT lung cancer screening exam. The calculation used radiation dose measurements . These patient radiation dose measurements using TLD are the only experiential contributions of this presentation. The rest of presentation uses published data. For me, an interesting technical issue remains (2009); how to calculate an effective dose from the measured entrance dose? This image from the poster of lung nodule phantom carrying set of thermal luminescent dosimeters (TLD) on a patient. The phantom with TLDs was placed on 5 patients during there lung cancer screening exam. The technique was 140 kVp, effective 20 mAs, 1 mm detector collimation, pitch 2. Mean dose was 7.3 mGy (.73 rads) with a coefficient of variation of 7%.  Should be able to use calculation of effective dose from chest radiograph to calculate effective dose. Calculate effective dose using several projection angles. This procedure has capabilities to manipulate patient size. |
