Early response assessment using 3'-deoxy-3'-[18F]fluorothymidine-positron emission tomography in high-grade non-Hodgkin's lymphoma.
OBJECTIVE
To evaluate 3'-deoxy-3'-[(18)F]fluorothymidine-positron emission tomography (FLT-PET) for early monitoring response of high-grade non-Hodgkin's lymphoma to treatment with cyclophosphamide-adriamycin-vincristine-prednisone chemotherapy with or without rituximab immunotherapy (R-CHOP/CHOP).


METHODS
Twenty-two patients with histologically proven high-grade non-Hodgkin's lymphoma scheduled to undergo first line treatment with R-CHOP/CHOP were included. All patients received baseline imaging before therapy with FLT-PET. For noninvasive assessment of treatment response, FLT-PET was repeated at following time points: group 1 (n = 6), 1 and 6 weeks after R-CHOP/CHOP; group 2 (n = 16), 2 days after rituximab and 2 days after CHOP application. Emission images were acquired 45 min after injection of 300 to 370 MBq of FLT. FLT uptake was quantified by region-of-interest technique on a lesion basis. Maximum standardized uptake values (SUV) for FLT were calculated using circular region of interest (diameter, 1.5 cm).


RESULTS
In all patients, morphologically proven lesions showed initially high FLT uptake (mean SUV, 8.1 +/- 3.9). In group 1, mean FLT SUV decreased 7 days after R-CHOP/CHOP by 77% (P < 0.001), the reduction in FLT SUV from baseline was 85% after 40 days (P = 0.003). In group 2, FLT uptake in patients without dexamethasone pretreatment revealed no significant reduction after rituximab (P = 0.3) but significantly decreased 2 days after CHOP to 32% compared with the baseline value (P = 0.004).


CONCLUSIONS
Administration of R-CHOP/CHOP is associated with an early decrease in lymphoma FLT uptake. Interestingly, there was no reduction of FLT uptake after rituximab alone, indicating no early antiproliferative effect of immunotherapy. FLT-PET seems to be promising for early evaluation of drug effects in lymphoma.
Herrmann
Ken
K
Department of Nuclear Medicine, Technische Universität München, Munich, Germany. ken.herrmann@web.de
Wieder
Hinrich A
HA
Buck
Andreas K
AK
Schöffel
Marion
M
Krause
Bernd-Joachim
BJ
Fend
Falko
F
Schuster
Tibor
T
Meyer zum Büschenfelde
Christian
C
Wester
Hans-Jürgen
HJ
Duyster
Justus
J
Peschel
Christian
C
Schwaiger
Markus
M
Dechow
Tobias
T
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D058846:Antibodies, Monoclonal, Murine-Derived; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003520:Cyclophosphamide / Q000627:therapeutic use; D004317:Doxorubicin / Q000627:therapeutic use; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011241:Prednisone / Q000627:therapeutic use; D019275:Radiopharmaceuticals; D000069283:Rituximab; D013936:Thymidine; D016896:Treatment Outcome; D014750:Vincristine / Q000627:therapeutic use
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone; D013936:Thymidine