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Original Article

The association of the uterine motion with bladder volume during
radiotherapy in gynecological malignancies

Bhandari Virendra, Mutneja Abhinav, Gurjar Omprakash, Saadvik Raghuram, Bagdare Priyusha,
Gupta Krishnlal, Singh Kanchan
Department of Radiation Oncology, Sri Aurobindo Medical College and PG Institute, Indore 452001, India.
Correspondence to: Dr. Bhandari Virendra, Department of Radiation Oncology, Sri Aurobindo Medical College and PG Institute, 401, Samyak Towers,
16/3 Old Palasia, Indore 452001, India. E-mail: virencancer@yahoo.co.in

A B S T R AC T
Aim: This study was performed to assess the extent of interfraction uterine motion during radiotherapy for cervical cancer and
uterine body carcinoma while maintaining a strict bladder filling protocol. Methods: Twenty-four patients with cervical cancer or
uterine body carcinoma who were treated on a linear accelerator, were recruited. During the course of external beam radiotherapy,
cone beam computed tomographic scans were taken, once at the start of treatment and then weekly until the completion of the
radiotherapy course. Patients were instructed to maintain a strict bladder filling protocol. After negating the effect of patient’s
setup error by offline cone beam computed tomographic imaging, the position of the uterus was defined in the clinical target
volume. Then the position of the uterus was compared in the following weekly scans. The position of the uterus was also correlated
with the position and the filling of the bladder. This change in uterus position was measured separately in the anterioposterior
(AP), superioinferior (SI), and lateral directions. Results: According to calculations based on weekly imaging, The mean values of
shift in AP, SI, and lateral directions were respectively 0.67, 0.29, and 0.23 The mean extent of motion in the uterine position on a
daily basis for individual patients ranged from -2.28 to +1.3 in AP, -0.56 to +0.71 in SI, and from -0.6 to +0.45 in lateral directions.
Conclusion: At least once a week cone beam computed tomography might be necessary to minimize the geometrical miss and
deliver the planned doses to the target tissue and normal structure provide best results with minimum toxicity by maintaining
a bladder volume of about 100 mL and an empty rectum during the whole course of treatment. The daily anatomical shift and
contour of the patients maintaining a bladder volume of approximately 100 mL with an empty rectum may result in asymmetrical
conforming to the planning target volume and hence appropriate and adequate planning target volume margins are required.

Key words: Uterine motion; weekly computed tomographic evaluation; intensity modulated radiotherapy; inter-fraction variation;
bladder volume

INTRODUCTION spare the adjacent organs; however, it does not account for
interfraction and intrafraction motion of various organs as
External beam radiotherapy (EBRT) plays a great role in well as reduction in tumor volume during treatment.
the management of female gynecologic cancers. Intensity
modulated radiotherapy (IMRT) and image guided This phenomenon did not need to be considered in the
radiotherapy (IGRT) are considered the treatment of choice conventional technique as it provided a uniform dose to all
for cervical cancer and uterus carcinomas. These new the structures included in the treatment field which avoids a
techniques have overtaken the conventional four-field box geometrical miss of the tumor. Therefore, motion of organs
technique as the preferred modality of treatment and have within the treatment area is a vital issue in IMRT and three
proven more efficacious in various studies. [1-3] The IGRT dimensional conformal radiotherapy (3D-CRT). During the
further reduces the radiation dose to the organs at risk (OAR) treatmenta steep dose gradient is usually present that uses
and thus further reduces toxicities. On the other hand, IMRT
has very strict clinical and planning target volumes (CTV This is an open access article distributed under the terms of the Creative
and PTV respectively) conforming to a particular volume to Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows
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How to cite this article: Virendra B, Abhinav M, Omprakash G,
Raghuram S, Priyusha B, Krishnlal G, Kanchan S. The association
of the uterine motion with bladder volume during radiotherapy in
DOI: gynecological malignancies. J Cancer Metasta Treat 2016;2:139-43.
10.20517/2394-4722.2015.68
Received: 03-09-2015; Accepted: 19-12-2015.

©2016 Journal of Cancer Metastasis and Treatment ¦ Published by OAE Publishing Inc. 139