Investigation of the Impact of Vaginal Marker Utilization on Radiotherapy Treatment Plans Created with Various...

Our aim is to compare treatment plans with vaginal markers used in radiotherapy target volume definition with those without markers, which we have not encountered in our literature searches, and to investigate whether patients with endometrial cancer (EC) can undergo treatment with a single simulation tomography.

A total of twenty patients with EC were randomly selected. All patients underwent a computerized tomography in the supine position. During the scan, the arms were folded over the chest, and the feet were fixed with a foot immobilizer. Tomography scans were performed with a vaginal marker. A total of four treatment plans were made by a medical physicist using tomography images with both vaginal markers (CT Set 1) and 0 Hounsfield units assigned to the vaginal marker (CT Set 2) under the same conditions.

The mean doses of maximum and mean of planning target volume (PTV) and critical organs were derived from the data obtained from the treatment plans created using CT Set 1 and CT Set 2. No significant differences were observed regarding PTV or critical organs when comparing the plans of CT Set 1 and CT Set 2 in both Treatment Planning Systems.

Dosimetric comparison of plans with and without vaginal markers, no difference was found in terms of dosimetric parameters. Therefore, we suggested that a clinical decision can be made to plan with vaginal markers, thus ensuring that the patient does not receive an unnecessary second tomography dose.