Positron emission tomography/computed tomography findings during therapy predict outcome in patients with diffuse large B-cell lymphoma treated with chemotherapy alone but not in those who receive consolidation radiation.
OBJECTIVE
To assess the value of mid-therapy positron emission tomography (PET) findings for predicting survival and disease progression in patients with diffuse large B-cell lymphoma, considering type of therapy (chemotherapy with or without radiation therapy).


METHODS
We retrospectively evaluated 294 patients with histologically confirmed diffuse large B-cell lymphoma with respect to age, sex, disease stage, International Prognostic Index score, mid-therapy PET findings (positive or negative), and disease status after therapy and at last follow-up. Overall survival (OS) and progression-free survival (PFS) were compared according to mid-therapy PET findings.


RESULTS
Of the 294 patients, 163 (55%) were male, 144 (49%) were age >61 years, 110 (37%) had stage I or II disease, 219 (74%) had International Prognostic Index score ≤2, 216 (73%) received ≥6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, and 88 (30%) received consolidation radiation therapy. Five-year PFS and OS rates were associated with mid-therapy PET status: PFS was 78% for those with PET-negative (PET-) disease versus 63% for PET-positive (PET+) disease (P=.024), and OS was 82% for PET- versus 62% for PET+ (P<.002). These associations held true for patients who received chemotherapy only (PFS 71% for PET- vs 52% PET+ [P=.012], OS 78% for PET- and 51% for PET+ [P=.0055]) but not for those who received consolidation radiation therapy (PFS 84% PET- vs 81% PET+ [P=.88]; OS 90% PET- vs 81% PET+ [P=.39]).


CONCLUSIONS
Mid-therapy PET can predict patient outcome, but the use of consolidation radiation therapy may negate the significance of mid-therapy findings.
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Electronic address: bdabaja@mdanderson.org.
Bouthaina S
BS
Dabaja
Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Kenneth
K
Hess
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Ferial
F
Shihadeh
Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Donald A
DA
Podoloff
Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
L Jeffrey
LJ
Medeiros
Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Osama
O
Mawlawi
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Isidora
I
Arzu
Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Yasuhiro
Y
Oki
Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Fredrick B
FB
Hagemeister
Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Luis E
LE
Fayad
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Valerie K
VK
Reed
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Aziza
A
Kedir
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Christine F
CF
Wogan
Office of the Executive Vice President and Physician-in-Chief, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Alma
A
Rodriguez
D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D003520:Cyclophosphamide / Q000008:administration & dosage; D003561:Cytarabine / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D018450:Disease Progression; D004317:Doxorubicin / Q000008:administration & dosage; D004334:Drug Administration Schedule; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D019275:Radiopharmaceuticals; D012074:Remission Induction; D012189:Retrospective Studies; D000069283:Rituximab; D012737:Sex Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D017211:Treatment Failure; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
D058846:Antibodies, Monoclonal, Murine-Derived; C571759:R-CHOP protocol; D019275:Radiopharmaceuticals; D003561:Cytarabine; D019788:Fluorodeoxyglucose F18; D000069283:Rituximab; D014750:Vincristine; D003907:Dexamethasone; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone; D008727:Methotrexate