Whole-body diffusion-weighted MR imaging for assessment of treatment response in myeloma.
OBJECTIVE
To determine the feasibility of whole-body diffusion-weighted (DW) magnetic resonance (MR) imaging for assessment of treatment response in myeloma.


METHODS
This prospective single-institution study was HIPAA-compliant with local research ethics committee approval. Written informed consent was obtained from each subject. Eight healthy volunteers (cohort 1a) and seven myeloma patients (cohort 1b) were imaged twice to assess repeatability of quantitative apparent diffusion coefficient (ADC) estimates. Thirty-four additional myeloma patients (cohort 2) underwent whole-body DW imaging before treatment; 26 completed a posttreatment imaging. Whole-body DW data were compared before and after treatment by using qualitative (ie, observer scores) and quantitative (ie, whole-body segmentation of marrow ADC) methods. Serum paraproteins and/or light chains or bone marrow biopsy defined response.


RESULTS
Whole-body DW imaging scores were significantly different between observers (P < .001), but change in scores between observers after treatment was not (P = .49). Sensitivity and specificity for detecting response according to observer scores were 86% (18 of 21 patients) and 80% (4 of 5 patients) for both observers. ADC measurement was repeatable: mean coefficient of variation was 3.8% in healthy volunteers and 2.8% in myeloma patients. Pretreatment ADC in cohort 2 was significantly different from that in cohort 1a (P = .03), but not from that in cohort 1b (P = .2). Mean ADC increased in 95% (19 of 20) of responding patients and decreased in all (five of five) nonresponders (P = .002). A 3.3% increase in ADC helped identify response with 90% sensitivity and 100% specificity; an 8% increase (greater than repeatability of cohort 1b) resulted in 70% sensitivity and 100% specificity. There was a significant negative correlation between change in ADC and change in laboratory markers of response (r = -0.614; P = .001).


CONCLUSIONS
Preliminary work demonstrates whole-body DW imaging is a repeatable, quantifiable technique for assessment of treatment response in myeloma.
From the Departments of Magnetic Resonance Imaging (S.L.G., C.M., D.J.C., V.A.M., C.J.S., N.M.D.) and Haemato-oncology (S.W., F.E.D., G.J.M.), Royal Marsden Hospital, Downs Rd, Sutton, Surrey SM2 5PT, England; and Departments of Clinical Magnetic Resonance (D.J.C., N.M.D.) and Molecular Pathology (F.E.D., G.J.M.), Institute of Cancer Research, Sutton, Surrey, England.
Sharon L
SL
Giles
Christina
C
Messiou
David J
DJ
Collins
Veronica A
VA
Morgan
Catherine J
CJ
Simpkin
Sharon
S
West
Faith E
FE
Davies
Gareth J
GJ
Morgan
Nandita M
NM
deSouza
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001897:Boronic Acids / Q000008:administration & dosage; D000069286:Bortezomib; D003520:Cyclophosphamide / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage; D006801:Humans; D000077269:Lenalidomide; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000473:pathology*; D010865:Pilot Projects; D011446:Prospective Studies; D011719:Pyrazines / Q000008:administration & dosage; D015203:Reproducibility of Results; D013792:Thalidomide / Q000008:administration & dosage / Q000031:analogs & derivatives; D016896:Treatment Outcome; D051598:Whole Body Imaging / Q000379:methods*
D001897:Boronic Acids; D011719:Pyrazines; D016179:Granulocyte Colony-Stimulating Factor; D013792:Thalidomide; D000069286:Bortezomib; D003907:Dexamethasone; D003520:Cyclophosphamide; D000077269:Lenalidomide