Lack of tumor uptake of 131-I labeled rituximab in a patient with a CD20 positive lymphoma lesion.
Radioimmunotherapy has emerged as a treatment modality for patients with CD20 positive B-cell non-Hodgkin's lymphoma (NHL). Prior to administration of a therapeutic dose, confirmation of uptake of the radiolabeled compound in tumor locations and calculation of an appropriate dose can be performed using a diagnostic dose and subsequent imaging. We report the case of a 69-year-old male with a relapsed mantle cell lymphoma scheduled for radioimmunotherapy, where diagnostic imaging with 131-I labeled rituximab revealed unexpected new insights with implications for treatment. Persistence of the mantle cell lymphoma in a lymph node in the left arm was demonstrated by an 18-F fluorodeoxyglucose scan. However, a scan after a diagnostic dose of 131-I labeled rituximab did not show any uptake of the tracer, even though subsequent cytological analysis unequivocally confirmed a CD20 positive B-cell population in the lesion. The administration of a therapeutic dose of 131-I labeled rituximab was therefore cancelled. We here discuss the mechanisms that may explain lack of targeting in a proven CD20-positive lymphoma and provide recommendations for further studies.
Department of Pharmacy & Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, The Netherlands.
L
L
Tran
A D R
AD
Huitema
W V
WV
Vogel
J H
JH
Beijnen
J W
JW
Baars
D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018951:Antigens, CD20 / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D006801:Humans; D000922:Immunotoxins / Q000008:administration & dosage / Q000493:pharmacokinetics; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000493:pharmacokinetics; D020522:Lymphoma, Mantle-Cell / Q000378:metabolism* / Q000532:radiotherapy*; D008297:Male; D016499:Radioimmunotherapy / Q000379:methods; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D000069283:Rituximab
D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D000922:Immunotoxins; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D000069283:Rituximab