PURPOSE: Due to the often quite extended treatment fields in cervical cancer radiotherapy, uncorrected rotational set-up errors result in a potential risk of target miss. This study reports on the residual rotational set-up error after using daily cone beam computed tomography (CBCT) to position cervical cancer patients for radiotherapy treatment. METHODS AND MATERIALS: Twenty-five patients with locally advanced cervical cancer had daily CBCT scans (650 CBCTs in total) prior to treatment delivery. We retrospectively analyzed the translational shifts made in the clinic prior to each treatment fraction as well as the residual rotational errors remaining after translational correction. RESULTS: The CBCT-guided couch movement resulted in a mean translational 3D vector correction of 7.4 mm. Residual rotational error resulted in a target shift exceeding 5 mm in 57 of the 650 treatment fractions. Three patients alone accounted for 30 of these fractions. Nine patients had no shifts exceeding 5 mm and 13 patients had 5 or less treatment fractions with such shifts. CONCLUSION: Twenty-two of the 25 patients have none or few treatment fractions with target shifts larger than 5mm due to residual rotational error. However, three patients display a significant number of shifts suggesting a more systematic set-up error.
PURPOSE: Due to the often quite extended treatment fields in cervical cancer radiotherapy, uncorrected rotational set-up errors result in a potential risk of target miss. This study reports on the residual rotational set-up error after using daily cone beam computed tomography (CBCT) to position cervical cancerpatients for radiotherapy treatment. METHODS AND MATERIALS: Twenty-five patients with locally advanced cervical cancer had daily CBCT scans (650 CBCTs in total) prior to treatment delivery. We retrospectively analyzed the translational shifts made in the clinic prior to each treatment fraction as well as the residual rotational errors remaining after translational correction. RESULTS: The CBCT-guided couch movement resulted in a mean translational 3D vector correction of 7.4 mm. Residual rotational error resulted in a target shift exceeding 5 mm in 57 of the 650 treatment fractions. Three patients alone accounted for 30 of these fractions. Nine patients had no shifts exceeding 5 mm and 13 patients had 5 or less treatment fractions with such shifts. CONCLUSION: Twenty-two of the 25 patients have none or few treatment fractions with target shifts larger than 5mm due to residual rotational error. However, three patients display a significant number of shifts suggesting a more systematic set-up error.
Authors: Luiza Bondar; Laura Velema; Jan Willem Mens; Ellen Zwijnenburg; Ben Heijmen; Mischa Hoogeman Journal: Strahlenther Onkol Date: 2014-08-27 Impact factor: 3.621
Authors: Richard Pötter; Kari Tanderup; Christian Kirisits; Astrid de Leeuw; Kathrin Kirchheiner; Remi Nout; Li Tee Tan; Christine Haie-Meder; Umesh Mahantshetty; Barbara Segedin; Peter Hoskin; Kjersti Bruheim; Bhavana Rai; Fleur Huang; Erik Van Limbergen; Max Schmid; Nicole Nesvacil; Alina Sturdza; Lars Fokdal; Nina Boje Kibsgaard Jensen; Dietmar Georg; Marianne Assenholt; Yvette Seppenwoolde; Christel Nomden; Israel Fortin; Supriya Chopra; Uulke van der Heide; Tamara Rumpold; Jacob Christian Lindegaard; Ina Jürgenliemk-Schulz Journal: Clin Transl Radiat Oncol Date: 2018-01-11