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Over the past 6 years, the authors evaluated 300 patients with hepatoma as part of phase 1 and 2 treatment protocol trials. Analysis of the available clinical data and radiographic studies revealed 22 patients (7.3%) with skeletal metastases demonstrated by radiography, computed tomography (CT), and/or nuclear scintigraphy. The plain film appearance of skeletal metastases from hepatoma was osteolytic in all cases. CT scanning best demonstrated the expansile, destructive nature of these metastases, which were often associated with large, bulky soft-tissue masses. Skeletal metastases from hepatomas demonstrated increased radiotracer uptake on standard bone scans and were gallium avid, similar to the hepatoma itself. In addition, they could be targeted therapeutically with I-131 antiferritin immunoglobulin. The most frequent sites of skeletal metastases were the ribs, spine, femur, pelvis, and humerus. An initial symptom in ten patients was skeletal pain corresponding to the osseous metastases. In five patients, pathologic fractures of the proximal femur or humerus developed and required total hip replacement or open-reduction internal fixation. Patients with long-standing cirrhosis or known hepatocellular carcinoma who also have skeletal symptoms should be evaluated for possible osseous metastases.

The circular harmonic transform (CHT) solution of the exponential Randon transform (ERT) is applied to single-photon emission computed tomography (SPECT) for uniform attenuation within a convex boundary. An important special case also considered is the linear (unattenuated) Radon transform (LRT). The solution is on the form of an orthogonal function expansion matched to projections that are in parallel-ray geometry. This property allows for efficient and accurate processing of the projections with fast Fourier transform (FFT) without interpolation or beam matching. The algorithm is optimized by the use of boundary conditions on the 2-D Fourier transform of the sinogram. These boundary conditions imply that the signal energy of the sinogram is concentrated in well-defined sectors in transform space. The angle defining the sectors depends in a direct way on the radius of the field view. These results are also obtained for fan-beam geometry and the linear Radon transform (the Fourier-Chebyshev transform of the sinogram) to demonstrate that the boundary conditions are a more general property of the Radon transform and a not a property unique to rectangular coordinates.

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One hundred five patients with hepatoma were treated with iodine 131 antiferritin in three sequential protocols in phase 1-2 trials. Therapy began in all trials with external beam irradiation and chemotherapy. The dosimetric results with 131I antiferritin indicated that 30 mCi (8 to 10 mCi/mg immunoglobulin G [IgG]) was sufficient to saturate the tumor. Tumor-effective half-life of the radioactive antibody was 3 to 5 days and was dependent on the species of animal from which the antibody was derived. This led to a 30 mCi on day 0 and 20 mCi on day 5 treatment schedule. Toxicity was predominantly thrombocytopenia. Due to clinical remission, cyclic therapy was next developed with antibodies from different species of animals. Rabbit, pig, monkey, and bovine antibodies were determined to produce the longest tumor-effective half-life and therefore the highest dose of radiation. Integration of 15 mg doxorubicin and 500 mg 5-fluorouracil (5-FU) with 131I antiferritin was accomplished next. Remission to external beam radiation was evaluated by computed tomography (CT) scan tumor volume computations that indicated that 22% of the patients had a partial remission (PR) from initial presentation to 1 month following external irradiation and chemotherapy. From the time of radioactive antibody administration, 48% of the patients (7% complete response [CR] and 41% PR) achieved remission to 131I antiferritin. Of 79 patients evaluated by CT scan tumor volumetrics 50% of the patients (7% CR and 43% PR) remitted to the entire treatment regimen. Patients not previously treated and without metastasis who were alpha fetoprotein positive (AFP+) had a 5-month median survival compared with AFP- median survival of 10 1/2 months. There were four CRs with one being 3 years and 6 months. The longest PR was 5 years and 8 months. These studies have demonstrated the toxicity and therapeutic activity of 131I antiferritin and the emerging role of radiolabelled antibody in cancer therapy.