title: Power Doppler Quantification in Assessing Gestational Trophoblastic Neoplasia.
abstract: OBJECTIVE
  The FIGO score cannot accurately stratify low-risk gestational trophoblastic neoplasia (GTN) patients who develop chemoresistance to single agent methotrexate chemotherapy. Tumour vascularisation is a key risk factor and its quantification may provide non-invasive way of complementing risk assessment.
  
  
  METHODS
  187 FIGO-staged, low-risk GTN patients were prospectively recruited. Power Doppler ultrasound was analysed using a quantification program. Four diagnostic indicators were obtained comprising the number of colour pixels (NCP), mean dB, power Doppler quantification (PDQ), and percentage of colour pixels (%CP). Each indicator performance was assessed to determine if they could distinguish the subset of low-risk patients who became chemoresistant.
  
  
  RESULTS
  There were 111 non-resistant and 76 resistant patients. NCP performed best at distinguishing these two groups where the non-resistant group had an average 3435 (± 2060) pixels and the resistant group 6151 (± 3192) pixels (p < 0.001). PDQ and %CP showed significant differences (p < 0.001) but had poorer performance (area under ROC curves were 72 % and 67 % respectively compared with 75 % for NCP). The mean dB index was not significantly different (p = 0.133).
  
  
  CONCLUSIONS
  Power Doppler ultrasound quantification shows potential for non-invasive assessment of tumour vascularity and can distinguish low-risk GTN patients who become chemoresistant from those who have an uncomplicated course with first line treatment.
authors.affiliation: Bioengineering, Imperial College London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Yuanwei
authors.initials: Y
authors.lastname: Li
authors.affiliation: Bioengineering, Imperial College London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Meng Xing
authors.initials: MX
authors.lastname: Tang
authors.affiliation: Medical Oncology, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Roshan
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: Imaging, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Daksha
authors.initials: D
authors.lastname: Patel
authors.affiliation: Bioengineering, Imperial College London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Eckersley
authors.affiliation: Bioengineering, Imperial College London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Barrois
authors.affiliation: Imaging, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Roddie
authors.affiliation: Medical Oncology, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Linda
authors.initials: L
authors.lastname: Dayal
authors.affiliation: Medical Oncology, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Savage
authors.affiliation: Medical Oncology, Charing Cross Hospital, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Seckl
authors.affiliation: Imaging, Imperial College, London, United Kingdom of Great Britain and Northern Ireland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Lim
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols; D019008:Drug Resistance, Neoplasm; D005260:Female; D031901:Gestational Trophoblastic Disease; D006801:Humans; D008727:Methotrexate; D008875:Middle Aged; D011247:Pregnancy; D012307:Risk Factors; D018608:Ultrasonography, Doppler
chemical_list: D008727:Methotrexate