Yuanwei Li MSc, BEng, Abstract Co-Author: Nothing to Disclose

Mengxing Tang, Abstract Co-Author: Nothing to Disclose

Daksha Patel, Abstract Co-Author: Nothing to Disclose

Mary Elizabeth Roddie MD, Abstract Co-Author: Nothing to Disclose

Guillaume Barrois, Abstract Co-Author: Nothing to Disclose

Adrian Kuok Pheng Lim MD, FRCR, Presenter: Luminary, Toshiba Corporation

Philip Savage, Abstract Co-Author: Nothing to Disclose

Michael Seckl MD, Abstract Co-Author: Nothing to Disclose

Gestational trophoblastic neoplasia (GTN) is curable if given appropriate chemotherapy treatment. However, in a proportion of patients, the FIGO score fails to accurately stratify low risk patients who develop chemoresistance after initial chemotherapy. The degree of tumour vascularisation is a key factor in risk assessment and therefore quantifying tumour vascularisation may provide an important non-invasive way of complementing risk assessment.

187 FIGO staged, low risk GTN patients were prospectively recruited. Baseline power Doppler ultrasound was analysed using a quantification program written in MATLAB. Four diagnostic indicators were obtained consisting of the number of colour pixels (NCP), mean dB, power Doppler quantification (PDQ), and the percentage of colour pixels (%CP). The performance of each indicator was then assessed to determine if they could distinguish the subset of low risk patients who became chemoresistant to first line treatment.

There were 111 non-resistant patients and 76 resistant patients. The NCP performed best at distinguishing these two group where the non-resistant group had an average value of 3435(±2060) and the resistant group 6151(±3192) pixels (p<0.001). PDQ and %CP also showed significant differences (p<0.001) but had poorer performance (area under the receiver operator curves were 72% and 67% respectively compared with 75% for NCP). The mean dB index did not reach significance (p=0.133).

Power Doppler ultrasound quantification shows much potential as a non-invasive method of assessing tumour vascularity in patients with GTN and can distinguish low risk patients who become chemoresistant from those who have an uncomplicated course with first line treatment.

Low risk GTN patients who become chemoresistant to single agent therapy can be more accurately staged at outset and thus given the appropriate chemotherapeutic regime at start of treatment.

Li, Y, Tang, M, Patel, D, Roddie, M, Barrois, G, Lim, A, Savage, P, Seckl, M, Power Doppler Quantification in Assessing Gestational Trophoblastic Neoplasia.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011113.html