Bakulev Scientific Center of Cardiovascular Surgery, Moscow, Russia

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18F-FDG PET in Patients with Lymphoma for the
Assessment of Therapy
L.A.Bokeria, I.P.Aslanidis, O.V.Mukhortova,
I.V.Shurupova, T.A.Katunina, Z.N.Shavladze,
D.L.Stroikovskii
Bakulev Scientific Center of Cardiovascular
Surgery, Moscow, Russia Reserch Center of Medical
Radiology, Obninsk, Russia Moscow City Oncologic
Hospital ?62, Moscow, Russia
Moscow 2006
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Background
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Purpose
The retrospective evaluation of 18F-FDG PET for
the assessment of therapy in patients with
lymphomas.
Material and Methods
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Baseline Characteristics
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Standard Protocol of Whole Body 18F-FDG PET
ECAT-EXACT-47 Siemens
Reconstraction of images an iterative algorithm
(OSEM) with attenuation correction
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Estimation of PET Results
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Results
The accuracy of PET was 89 (51/57 true positive
and true negative results).
PET altered the treatment approach in 63 of
patients (36/57).
Two main management changes from
planned radio- or chemotherapy to no treatment
from biopsy to no further
intervention.
An active management was changed to no
treatment in 21/36 patients.
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Results
PET accuracy depending on presence of baseline
PET (n 57)
TN true-negative TP true-positive FN
false-negative FP false-positive.
The baseline FDG-PET should be performed in
patients with low-grade or with infrequent
histological types of NHL when FDG-avidity is
less predictable.
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False-positive PET-result
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PET for treatment management
No changes of treatment
delayed scan (after hydrotation and 40 mg of
Lasix)
No viable tumor
B-cell abdominal NHL in 10 days after
chemotherapy
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PET for treatment management
From no treatment to continuation of chemotherapy
A viable tumor in residual mass
soiling of urine
Burkitt lymphoma, in 14 days after 6 cycles of
chemotherapy
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Time-point of PET-scans
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Results
PET accuracy depending on time point for scanning
(n 57)
A shorter interval between the completion of
chemotherapy and scanning doesnt decrease PET
accuracy for treatment assessment in lymphoma
patients.
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Results
Frequency of FDG uptake in the radiotherapy
area depending on time point for scanning (n
27).
PET in lymphoma patients should be performed in
the shortest time after completion of
radiotherapy before the non-specific treatment
effects appear.
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PET for the treatment assessment
Standard time-point of PET
Mediastinal HD
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PET for the treatment assessment
Standard time-point of PET
FDG uptake in the mediastinum
Esophageal stent
SUV max 2,7
Mediastinal HD, in 3 months after radiotherapy
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PET for the treatment assessment
The early time-point of PET
HD, III B st., in 6 days after radiotherapy
SUV max 1,6
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Conclusion
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Conclusion
The intensive FDG uptake in the area of fibrosis
is a most frequent reason of false-positive
results in lymphoma patients after radiotherapy.
The careful comparison of PET and CT results,
knowledge of radiotherapy ports helps to exclude
incorrect PET conclusions. PET scan obtained in
the shortest time after completion of
radiotherapy allows correct assessment of
treatment and may play an important role for
future management.
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PET for diagnostics of diffuse lesions
Hepato-splenomegalia on CT in patient with
relapse of HD.
Baseline
Post-therapeutic
Sclerosis in the lien!
No uptake in hepar!
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PET for treatment management
From chemotherapy to observation
No viable tumor
In 14 days after antirecurrent chemotherapy
Baseline PET
Relapse of B-cell NHL
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PET for treatment management
From no treatment to radiotherapy
A viable tumor in residual mass
Hodgkins disease, II B st., after 6 cycles of
chemotherapy