Uterine Artery Pulsatility Index as an Emerging Promising Marker in the Management of Gestational Trophoblastic Neoplasia

Abstract

Objective:Increasing new blood vessel formation (neoangiogenesis) within tumors is one of the adverse prognostic factors for survival in several cancers. Neoangiogenesis in vivo can be assessed by Doppler ultrasonography by measuring uterine artery pulsatility index (UAPI) in patients with gestational trophoblastic neoplasia (GTN). In this study we assessed whether UAPI can be an independent prognostic factor predictive of response to chemotherapy. Methods:This was a prospective observational study conducted in Medical College, Kolkata from May 2011 to December 2012. Twenty-two patients of GTN had their FIGO prognostic scoring done, 19 patients were of low risk (scored 6) and three patients were of high risk (score > 6). The 3 high risk GTN patients were excluded from the study. The study population therefore consisted of 19 low risk (scored 6) patients of GTN who were treated with fortnightly cycles of 50 mg of methotrexate IM on days 1, 3, 5 and 7 and with 15 mg of folinic acid rescue IM on days 2, 4, 6 and 8. Treatment was continued in all patients till hCG values were negative and 2 further cycles of chemotherapy were given. The patients were followed up with UAPI and serum -hCG levels every 2 weeks following chemotherapy to assess whether fall in -hCG correlated with rise in UAPI values following chemotherapy. Data collected were analyzed using standard statistical protocol. Results:The -hCG concentration of these patients at the time of diagnosis ranged from 1400 to 210,000 mIU/ml and UAPI varied from 0.47 to 2.1. The mean  hCG of these 19 patients before chemotherapy (week 0) was 63705.47 mIU/ml and subsequently following chemotherapy at the end of 16 weeks was 1.64 mIU/ml. The mean UAPI before chemotherapy (week 0) was 1.33 and following chemotherapy at the end of 16 weeks was 1.952. All patients achieved complete remission with chemotherapy. The fall in beta-hCG levels corelated with the rise in UAPI values. Conclusion:This study provides proof of principle that the UAPI can serve as a noninvasive in vivo measure of functional tumor vascularity, which independently can predict the response to chemotherapy.