An inter–individual comparision of radiotherapy in prone and supine positioning in patients of carcinoma cervix – a prospective study

Dr. Swarnendu Biswas; Dr. Tapas Kumar Das

Volume : IX, Issue : II, February - 2020

An inter–individual comparision of radiotherapy in prone and supine positioning in patients of carcinoma cervix – a prospective study

Dr. Swarnendu Biswas, Dr. Tapas Kumar Das

Abstract :

Background: Radical radiotherapy along with concurrent chemotherapy followed by achytherapy is the standard of care of advanced carcinoma cervix. This treatment carries a risk of inadvertent normal tissue irradiation of the small bowel, bladder and rectum. Various efforts have been made to reduce bowel toxicity by pelvic radiotherapy. Among them radiotherapy in prone position have been matter of interest for long. objectives : To compare the dose volume histograms of organs at risk (small bowel, bladder and rectum ) and planning target volumes in supine and prone positions. Materials & methods: A total 60 histologically proven newly diagnosed cases of carcinoma cervix stage I – IVA, age 18 – 70 years, ECOG score 0 – 1, with informed consent were randomized in two groups ( prone & supine position) for radical radiotherapy at dose 50 Gy in 25 fractions , over 5 weeks, with Concurrent cisplatin 40 mg/m2 weekly for 5 weeks followed by Intracavitory achytherapy for all patients with 7 Gy in 3 fractions. 30 patients were treated in prone and 30 were treated in supine position with proper CTV & PTV contouring. Dosimetric analysis was done with Dose Volume Histogram and toxicity of bladder, bowel was assessed. Results & Discussion: In my study I found significant less bowel volume receiving more than 20 Gy in prone position than in supine position, though no statistically significant different was seen in dose <=20 Gy. Dose received by 195 cc of bowel bag was significantly more in supine position than in prone position with a P Value of <0.001, also 45 Gy dose received by Bowel volume was more in supine position than in prone position mean V45 in prone position was 193 cc with STD.DEV of 13, and in supine position mean V45 was 216cc with STD.Dev of 12 cc,P–value <0.001. Volume of PTVmean in prone position 890.25 cc with STD.DEV. of 83.11 and in supine position PTVmean was 958 with STD Dev. Of 231.91, P–Value being 0.01. Conclusion : Prone position can be used instead of supine position for Pelvic field radiation, in patients of Carcinoma Cervix for better bowel protection.