Comparison of radiation dose estimation for myeloablative radioimmunotherapy for relapsed or recurrent mantle cell lymphoma using (131)I tositumomab to that of other types of non-Hodgkin's lymphoma.
Patients with relapsed or refractory mantle cell lymphoma (MCL) demonstrate poor survival after standard treatment. Myeloablative radioimmunotherapy (RIT) using (131)I tositumomab (anti-CD20) has the ability to deliver specific radiation-absorbed dose to antigen-bearing tumor. We reviewed normal organ radiation- absorbed doses in MCL patients.


METHODS
Records of patients with MCL (n =25), who received myeloablative RIT between January 1996 and December 2003 were reviewed. Individual patient radiation dosimetry was performed on all patients after a trace-labeled infusion of (131)I tositumomab (mean = 348 MBq), to calculate the required amount of radioactivity for therapy, based on medical internal radiation dose (MIRD) schema.


RESULTS
Mean organ residence times (hour) corrected for computed tomography (CT) derived organ volumes for MCL, were as follows: Lungs: 9.0; Liver: 12.4; Kidneys: 1.7; Spleen: 2.17; Whole Body: 62.4 and mean radiation absorbed doses mGy/Mbq were: Lungs: 1.2; Liver: 1.1; Kidneys: 0.85; Spleen: 1.7; Whole Body: 0.21. This is similar to patients with other non-Hodgkin's lymphoma (NHL). Patients received a mean activity of 21 GBq of (131)I (range, 11.5-41.4) for therapy estimated to deliver 25 Gy to the normal organ receiving the highest radiation-absorbed dose.


CONCLUSIONS
Myeloablative RIT using (131)I tositumomab results in normal organ radiation-absorbed doses similar to those in patients with other non-Hodgkin's lymphoma, and is suitable for treating patients with relapsed or refractory MCL.
Rajendran
Joseph
J
Department of Radiology, University of Washington, Seattle, WA 98195, USA. rajan@u.washington.edu
Gopal
Ajay
A
Durack
Lawrence
L
Fisher
Darrell
D
Press
Oliver
O
Eary
Janet
J
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000276:immunology / Q000532:radiotherapy*; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000532:radiotherapy; D019653:Myeloablative Agonists / Q000627:therapeutic use; D009364:Neoplasm Recurrence, Local; D009928:Organ Specificity; D011829:Radiation Dosage; D016499:Radioimmunotherapy; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D019653:Myeloablative Agonists; C119496:tositumomab I-131