PURPOSE: To evaluate the magnitude of cervix regression and motion during external beam chemoradiation for cervical cancer. METHODS AND MATERIALS: Sixteen patients with cervical cancer underwent computed tomography scanning before, weekly during, and after conventional chemoradiation. Cervix volumes were calculated to determine the extent of cervix regression. Changes in the center of mass and perimeter of the cervix between scans were used to determine the magnitude of cervix motion. Maximum cervix position changes were calculated for each patient, and mean maximum changes were calculated for the group. RESULTS: Mean cervical volumes before and after 45 Gy of external beam irradiation were 97.0 and 31.9 cc, respectively; mean volume reduction was 62.3%. Mean maximum changes in the center of mass of the cervix were 2.1, 1.6, and 0.82 cm in the superior-inferior, anterior-posterior, and right-left lateral dimensions, respectively. Mean maximum changes in the perimeter of the cervix were 2.3 and 1.3 cm in the superior and inferior, 1.7 and 1.8 cm in the anterior and posterior, and 0.76 and 0.94 cm in the right and left lateral directions, respectively. CONCLUSIONS: Cervix regression and internal organ motion contribute to marked interfraction variations in the intrapelvic position of the cervical target in patients receiving chemoradiation for cervical cancer. Failure to take these variations into account during the application of highly conformal external beam radiation techniques poses a theoretical risk of underdosing the target or overdosing adjacent critical structures.
PURPOSE: To evaluate the magnitude of cervix regression and motion during external beam chemoradiation for cervical cancer. METHODS AND MATERIALS: Sixteen patients with cervical cancer underwent computed tomography scanning before, weekly during, and after conventional chemoradiation. Cervix volumes were calculated to determine the extent of cervix regression. Changes in the center of mass and perimeter of the cervix between scans were used to determine the magnitude of cervix motion. Maximum cervix position changes were calculated for each patient, and mean maximum changes were calculated for the group. RESULTS: Mean cervical volumes before and after 45 Gy of external beam irradiation were 97.0 and 31.9 cc, respectively; mean volume reduction was 62.3%. Mean maximum changes in the center of mass of the cervix were 2.1, 1.6, and 0.82 cm in the superior-inferior, anterior-posterior, and right-left lateral dimensions, respectively. Mean maximum changes in the perimeter of the cervix were 2.3 and 1.3 cm in the superior and inferior, 1.7 and 1.8 cm in the anterior and posterior, and 0.76 and 0.94 cm in the right and left lateral directions, respectively. CONCLUSIONS: Cervix regression and internal organ motion contribute to marked interfraction variations in the intrapelvic position of the cervical target in patients receiving chemoradiation for cervical cancer. Failure to take these variations into account during the application of highly conformal external beam radiation techniques poses a theoretical risk of underdosing the target or overdosing adjacent critical structures.
Authors: Karen Lim; Beth Erickson; Ina M Jürgenliemk-Schulz; David Gaffney; Carien L Creutzberg; Akila Viswanathan; Lorraine Portelance; Sushil Beriwal; Aaron Wolfson; Walter Bosch; Jennifer De Los Santos; Catheryn Yashar; Anuja Jhingran; Mahesh Varia; Issam El Naqa; Bronwyn King; Anthony Fyles Journal: Pract Radiat Oncol Date: 2015-07-02
Authors: Ann H Klopp; Jennifer Moughan; Lorraine Portelance; Brigitte E Miller; Mohammad R Salehpour; Evangeline Hildebrandt; Jenny Nuanjing; David D'Souza; Luis Souhami; William Small; Rakesh Gaur; Anuja Jhingran Journal: Int J Radiat Oncol Biol Phys Date: 2013-05-01 Impact factor: 7.038
Authors: Alexander J Lin; Elizabeth Kidd; Farrokh Dehdashti; Barry A Siegel; Sasa Mutic; Premal H Thaker; Leslie S Massad; Matthew A Powell; David G Mutch; Stephanie Markovina; Julie Schwarz; Perry W Grigsby Journal: Int J Radiat Oncol Biol Phys Date: 2018-11-14 Impact factor: 7.038