Prospective SPECT-CT Organ Dosimetry-Driven Radiation-Absorbed Dose Escalation Using the In-111 (In)/Yttrium 90 (Y) Ibritumomab Tiuxetan (Zevalin) Theranostic Pair in Patients with Lymphoma at Myeloablative Dose Levels.

Purpose: We prospectively evaluated the feasibility of SPECT-CT/planar organ dosimetry-based radiation dose escalation radioimmunotherapy in patients with recurrent non-Hodgkin's lymphoma using the theranostic pair of In and Y anti-CD20 ibritumomab tiuxetan (Zevalin) at myeloablative radiation-absorbed doses with autologous stem cell support. We also assessed acute non-hematopoietic toxicity and early tumor response in this two-center outpatient study.

Methods: 24 patients with CD20-positive relapsed or refractory rituximab-sensitive, low-grade, mantle cell, or diffuse large-cell NHL, with normal organ function, platelet counts > 75,000/mm, and <35% tumor involvement in the marrow were treated with Rituximab (375 mg/m) weekly for 4 consecutive weeks, then one dose of cyclophosphamide 2.

Initial Experience with Tositumomab and I-131-Labeled Tositumomab for Treatment of Relapsed/Refractory Hodgkin Lymphoma.

Purpose: To determine the maximum tolerated dose (MTD) of [I]tositumomab in patients with refractory/recurrent Hodgkin lymphoma (HL) and to preliminarily determine if [I]tositumomab has activity against HL and if positron emission tomography (PET) with 2-deoxy-2-[F]fluoro-D-glucose ([F]DG) performed 6 weeks post-therapy predicted 12-week response.

Procedures: Separate dose-finding studies were performed for patients with and without prior transplant. A single therapeutic total body radiation dose (TBD) of [I]tositumomab was administered.

Comparison of organ residence time estimation methods for radioimmunotherapy dosimetry and treatment planning--patient studies.

The estimation of organ residence time is essential for high-dose myeloablative regimens in radioimmunotherapy (RIT). Frequently, this estimation is based on a series of simple planar scans and planar processing. The authors previously performed a simulation study which demonstrated that the accuracy of this methodology is limited compared to a hybrid planar/SPECT residence time estimation method.

18F-FDG PET/CT for monitoring the response of lymphoma to radioimmunotherapy.

Unlabelled: We retrospectively evaluated 18F-FDG PET/CT for monitoring the response of non-Hodgkin's lymphoma to radioimmunotherapy.

Methods: A total of 33 clinical patients received 131I-tositumomab (n=23) or 90Y-ibritumomab tiuxetan (n=10) and underwent 18F-FDG PET/CT scans before radioimmunotherapy and at 12 wk after radioimmunotherapy. A third scan was performed on 13 patients at 24 wk after radioimmunotherapy, 12 of whom did not receive interval therapy.

Comparison of 90Y-ibritumomab tiuxetan and 131I-tositumomab in clinical practice.

Unlabelled: We retrospectively evaluated our single-center clinical experience with (90)Y-ibritumomab tiuxetan and (131)I-tositumomab for therapy of refractory non-Hodgkin's lymphoma (NHL). We evaluated the hypothesis that the patient-specific dosing regimen used with (131)I-tositumomab results in less bone marrow toxicity than does the weight-based dosing regimen used with (90)Y-ibritumomab tiuxetan.

Methods: Thirty-eight patients (25 male and 13 female; median age, 64 y) received radioimmunotherapy for NHL (20 received (90)Y-ibritumomab tiuxetan; 18 received (131)I-tositumomab).