8th Baltic Congress of Radiology

Interventional Radiology

oral abstract

Objectives of the study foremost is to evaluate organ dynamics in distance radiotherapy for gynecological patients. Objectives also include summation and analysis of literature on pelvic organ anatomy, tumors and treatment methods,compile and analyse literature on the treatment of gynecological tumors using radiotherapy, analyse literature on patient preparation and procedure in external radiotherapy ,analyse internal organ dynamics in external beam therapy and lastly summarize data obtained in the study and make a conclusion. Hypothesis tested , patient preparation – following diet, preparation of the bladder and rectum before the procedure promotes quality radiation therapy.

Prospective research method was used for the study in one of the largest hospitals in Latvia. The study analyses data from 250 Cone beam computed tomography images or CBCT in short of 50 gynecological patients who have completed treatment. For each patient out of 24 fractions, six fractions or 20% of the course of treatment corresponding to one week of treatment is analysed and in terms of the total number of patients studied is sufficient to confirm or deny the hypothesis.

Results show that the movement of uterus and cervix depends on the patient's level of preparedness. From the data obtained from analyzing 250 CBCT images, 38% of patients had an accurately filled bladder. In 5% of cases, the bladder was overfilled, promoting deviation in the ventral (z-axis) and caudal (y-axis) directions for uterus and cervix. Unfilled bladder, on the other hand, accounted for 4% of dorsal deviations of the uterus and cervix. Patients had a well-prepared rectum in 31% of cases, while the intestinal gas and incomplete bowel movements in 38% of cases. As with the bladder, the contents in the rectum shift the target volume in ventral direction. In some cases, the rectum shifts laterally (x axis). According to the observations, the contents in the colon or gases far from the target can also affect the localization of the uterus and cervix - when the filled colon puts pressure on the bladder,bladder shifts the target volume in the ventral direction. The exact position of the symphysis is no less important factor in quality radiotherapy. After analysis of the data, in 5% of cases the condition of the symphysis was more ventral or dorsal compared to the planning CBCT images. The main influencing factors of the uterus and cervix are the bladder, which, when not fully filled up or overfilled causes an average difference of up to 0.4 cm between planning CT images. The next main reason is the condition of the symphysis, which causes an average difference of up to 0.3 cm. It should be noted that the condition of the symphysis may increase or decrease the size of the difference, depending on the state of the other pelvic organs. The smallest difference was caused by the intestines where incomplete bowel movements caused 0.2cm difference. As with symphysis, the incomplete bowel movements depending on the location and size may increase the difference.

In conclusion Performing CBCT prior to each radiotherapy session provides information on the actual localization of the uterus and cervix relative to the planning CT images and eliminates the possibility of positioning errors. Making corrections for each session using CBCT, the intended dose is delivered at the target location reducing the side effects of radiotherapy and the risk to the surrounding healthy tissues and organs. Analyzing the obtained data, a correlation was observed between the dynamics of the uterus, cervix and intestinal and bladder filling. To ensure quality radiotherapy, patients should follow a prescribed diet and undergo a preparatory process prior to radiotherapy.

''Preparation of gynecological patients in external beam therapy'' objectives are to evaluate organ dynamics in distance radiotherapy for gynecological patients. Hypothesis tested , patient preparation – following diet, preparation of the bladder and rectum before the procedure promotes quality radiation therapy. Research was done in one of the largest hospitals in Latvia. The study analysed data from 250 images from 50 gynecological patients who have completed treatment

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