Haematologica 2003 - Supplements

187
Both F-18 FDG PET and Tc-99m sestamibi are
informative imaging modalities which frequently aid the
clinical management of patients with Multiple Myeloma
(MM).
Mileshkin L, Blum R, Seymour JF, Prince HM, Patrikeos A,
Hicks R
Peter MacCallum Cancer Institute, Melbourne, Australia
Objective: Multiple myeloma (MM) may be difficult to assess
due to: absent/small volume paraprotein; minimal bone marrow
infiltration/biopsy sampling variation; persisting pain or
abnormalities on plain skeletal surveys(SS) following therapy
which may not represent active disease. In previous small studies,
both FDG-PET(PET) and Tc-99m sestamibi scans(MIBI) have
identified sites of occult bony and soft tissue disease in MM. This
analysis aims to compare the results of PET and MIBI in MM.
Methods: Over Jan 1999–Aug 2002, 34 pts had PET, 21 of whom
had concurrent MIBI. Medical records and scan results were
reviewed to assess: (a)ability of the scans to identify otherwise
occult disease; (b)concordance between the scans; and (c)impact
on management.
Results: Disease state was: newly diagnosed (8pts), remission
(3pts), relapsed/refractory (17pts), MGUS (2pts), isolated
plasmacytoma(4pts). 16 had scans at diagnosis or as baseline, 13
for suspected progression(PD), 3 for re-staging, and 2 to
investigate persistent fever. 14 (41%) had difficult to assess
disease with: small volume/absent paraprotein (10pts),
extramedullary disease only (3pts), disproportionate osteoporosis
(1pt). In 14/34 cases (41%), PET identified additional sites of
disease not seen on routine SS. Additional sites were soft tissue in
4 cases, and bony in 10. 11 of these 14 cases were pts with known
active disease at other sites. The additional sites were consistent
with myeloma, and confirmed with further imaging or biopsy in
5. 3 cases showed unexpected additional sites in pts thought to
have limited/stable disease. Additional imaging or biopsy
confirmed all were true positives. In 11/21 cases(52%), additional
sites of disease not seen on routine SS, were identified on
concurrent MIBI. Additional sites were soft tissue in 3, and bony
in 10(both in 2). 7 of 11 cases were pts with known active disease
at other sites. The additional sites were consistent with myeloma,
and confirmed with further imaging or biopsy in 4. 4 cases
showed unexpected additional sites in pts thought to have
limited/stable disease. Additional imaging/biopsy confirmed 2
true positives and 2 false positives. MIBI generally detected more
disease sites than PET: median #sites/case = 1 (0-4) vs 3 (0-8);
P=0.01. PET and MIBI were concordant in 8 cases (6 both
negative scans). In 10/21 cases, MIBI detected additional sites to
PET(all bony). In 3 cases, PET detected additional sites to
MIBI(2 bony, 1 soft tissue). In 15/34 cases(44%), scan results led
to a management change. In 8 cases, stable or responsive disease
was confirmed and pts continued their treatment plan. In 2 cases,
radiotherapy fields were altered to encompass active disease sites.
In 2 cases, treatment was changed due to detection of PD. In 3
cases of pts thought to have only isolated plasmacytoma, a
diagnosis of MM was made and systemic therapy commenced.
Conclusions: PET and MIBI are useful additional diagnostic tools
for detecting otherwise occult MM sites. Their use should be
considered in the work-up of pts with presumed solitary
plasmacytomas to exclude the presence of MM. MIBI detects
more additional disease sites than PET. However, PET scans
have detected sites of soft tissue disease not seen with other
imaging modalities.
188
Prospective Evaluation of 460 Patients from Total
Therapy II – Identification of Characteristics on
Baseline MRI Examinations of Prognostic Significance
– Importance of Focal Lesions (FL) in Multiple Myeloma
(MM)
Ronald Walker, MD1, Bart Barlogie, MD, PhD2, Joth
Jacobson, MS3, John Shaughnessy, PhD2, Joshua
Epstein, PhD2, Edguardo Angtuaco, MD1, Elias Anaissie,
MD2, Choon-Kee Lee, MD2, Raymond Thertulien, MD,
PhD2, Frits van Rhee, MD, PhD2, Maurizio Zangari, MD,
PhD2, Ernest Ferris, MD1, and Guido Tricot, MD, PhD2
2Myeloma Institute for Research and Therapy, 1Department of
Radiology, University of Arkansas for Medical Sciences, Little
Rock, AR 72205, and 3Cancer Research and Biostatistics, 1730
Minor Ave. STE 1900, Seattle, WA 98101-1468
MM frequently presents with focal plasmacytoma lesions (FL)
superimposed on diffuse infiltration of the marrow which can be
recognized on MRI (T1-weighted and STIR images). These
MRI-FL have previously been shown to contain malignant
plasma cells morphologically, by flow cytometry, cytogenetics
and FISH, and by gene expression profiling. These lesions can
be associated with or progress to osteolytic lesions (OL)
recognized on standard X-rays, and can progress when treatment
is ineffective. To evaluate the significance of diffuse and FL
patterns on MRI in MM patients enrolled in TT II (intensive
remission induction, tandem autotransplants with melphalan 200
mg/m2, consolidation chemotherapy for 1 year and interferon
maintenance, up-front randomization to +/- thalidomide), 460
baseline MRI examinations of the axial skeleton were
prospectively evaluated in terms of signal characteristics on T1-
weighted and short-tau inversion recovery (STIR) sequences for
the presence of hyper-, iso- or hypointense background,
homogeneous versus heterogeneous overall signal, and number of
FL present (FL being a sharply circumscribed region thought to
be myeloma measuring ≥5 mm in diameter). The only
statistically significant (p ≤0.01) prognostic characteristic of
baseline MRI was the number of FL in the spine and pelvis,
revealing significantly superior event-free survival (EFS) and
overall survival (OS) with < 5 FL. Four-year estimates of EFS
were 68% for < 5 FL, 54% for 5–20 FL, and 37% for FL ≥ 21
(p=0.0002). Similarly, 4 yr OS was 78% with < 5 FL compared
to 62% for 5-20 FL and 35% for FL ≥ 21 (p=0.001).
Examination with Cox multivariate regression for potential
associations with standard prognostic factors (SPF) such as β2M
≥ 4.0, CRP ≥ 4.0, LDH ≥ 190, cytogenetic abnormalities (CA),
albumin < 3.5, platelets < 150K, HGB < 10, and creatinine ≥ 2
revealed superior significance of number of FL ≥ 5 in OS (HR
1.9, CI 1.2, 3.1, p=0.008) and EFS (HR 1.9, CI 1.3, 2.8, p=0.002),
and of any CA in OS (HR 2.9, CI 1.7, 4.8, p