Chira Ranjan K1, Shivakumar G1, Lavanya N1, Supriya C1, Reena E1, Rajesh K1, Chetana V1, Vivek S1, Dandpani E1 and Umesh M2*
1Department of Radiation Oncology, Homi Bhabha National Institute, India
2Department of Radiation Oncology, Homi Bhabha Cancer Hospital and Research Centre, India
Introduction: Utero-cervical organ motion during External Beam Radiotherapy (EBRT) of cervical cancers poses a major challenge in treatment delivery. Accurate assessment of such organ motion is essential to derive appropriate internal target volume. We evaluated Trans-Abdominal Ultrasonography (TAUS) based image-guided radiotherapy system - ‘Clarity® (Elekta)’ for cervical cancer to estimate the magnitude and directions of the utero-cervical organ motion. Methods: Fifteen patients of locally advanced cervical cancers planned for radical radio (chemo) therapy consented to this observational study. All underwent TAUS to determine the position of utero-cervical complex using the Clarity system during radiotherapy simulation. At the time of radiotherapy treatment delivery, the set-up errors were corrected using Cone-Beam Computed Tomography (CBCT), and then the position of utero-cervical complex was compared to that of simulation again using the Clarity TAUS system. The shifts of utero-cervical complex were documented in various directions and compiled for analysis. Results: A total of 72 (73%) of 98 image sets were evaluable. The mean shifts for utero-cervical motion ranged from 3.2 (± 7.6) mm to 10.7 (± 10.5) mm. The organ motion was higher in anterior and superior directions [10.7 (± 10.5) mm and 9.7 (± 17.9) mm respectively] and also was higher during the latter part of the radiation treatment course. Conclusion: TAUS combined with CBCT appears to be a feasible tool for image guidance and to assess uterocervical organ motion during EBRT for cervical cancers. In our initial results, organ motion appears to be variable depending on the direction of motion and timeline during the course of treatment.
Chira Ranjan K, Shivakumar G, Lavanya N, Supriya C, Reena E, Rajesh K, et al. Transabdominal Ultrasonography-Based Image Guidance during External Beam Radiotherapy for Cervical Cancer - An Initial Experience. J Gynecol Oncol. 2021; 4(1): 1051.