Magnetic resonance imaging and 67Ga scan versus computed tomography in the staging and in the monitoring of mediastinal malignant lymphoma: a prospective pilot study.

PURPOSE: To assess the potential value of magnetic resonance imaging (MRI) combined with 67Ga single-photon emission computed tomography (SPECT) versus computed tomography (CT) in the staging and in the monitoring of mediastinal malignant lymphoma. MATERIALS AND METHODS: Twenty-three patients, referred to our institute for the evaluation of lymphoma, underwent CT, 67Ga scan, and MRI between April 1993 and February 1996 at sequential intervals. The tests studied (MRI, 67Ga, and CT) were performed according to the following schedule: 1) before start of therapy; 2) after four courses of chemotherapy; and 3) 2, 6, 12, and 18 months after the end of treatment. RESULTS: All patients studied at the time of diagnosis had abnormal gallium accumulation in the mediastinum as well as pathologic CT and pathologic signal intensity at MRI. Six months after the end of treatment full consistency was found between the results of MRI and SPECT, whereas during treatment and 2 months after the end of therapy MRI and 67Ga scan were not in agreement in nine patients. In the 23 patients in follow-up, in CT there were nine false-positive and three false-negative findings; in SPECT three false negatives; in MRI one false positive and one false negative. CONCLUSION: MRI can give morphologic information similar to CT, even superior due to multiplanarity and with major precision in the distinction between fibrosis and active disease. MRI is thus an alternative to CT. The association with SPECT allows a great diagnostic accuracy in the positive and negative predictive value.

A brain metastasis, with no uptake of 99mTc-ECD, secondary to Hurtle cell carcinoma of the thyroid.

Visualization of cerebral perfusion with Single Photon Emission Computed Tomography (SPET) needs lipophil radiotracers which are able to cross the intact blood-brain-barrier (BBB); moreover local uptake must reflect regional cerebral blood flow. In the last decade many radiopharmaceuticals have been suggested and employed for this purpose. Recently a new molecule has been synthesized: technetium-99m-labeled ethyl cysteinate dimer (99mTc-ECD). Commonly, SPET of the brain with perfusion tracers is performed to identify ischemic regions. We describe a patient with a bulky cerebral metastasis, secondary to Hurthle cell carcinoma of the thyroid, which concentrated radioiodine. Brain metastases secondary to differentiated carcinoma of the thyroid are very rare and when treated with 131-I may provoke serious neurological problems. Therefore we decided to perform a brain SPET with 99mTc-ECD to exclude regional perfusion defects and deafferentation phenomena. Brain CT showed only the large metastasis. SPET images, reconstructed according to standard tomographic planes of the head: transverse, coronal and sagittal revealed no uptake of 99mTc-ECD within the metastasis and no regional perfusion defects related to compression phenomena or deafferentation. 99mTc-ECD has never been used to image cerebral neoplasm of whatever origin.

Radioiodine-131 therapy for well-differentiated thyroid cancer--a quantitative radiation dosimetric approach: outcome and validation in 85 patients.

For almost five decades, 131I treatment of thyroid cancer has been based empirically on administered activity rather than on actual radiation doses delivered. In 1983, we defined radiation dose thresholds for successful treatment. This report is concerned with the subsequent validation of those thresholds in 85 patients. The successful ablation of thyroid remnants occurred after a single initial 131I administration in 84% of inpatients and in 79% of outpatients when treatment was standardized to a radiation dose of at least 30,000 cGy (rad). Administered activities low enough to permit outpatient therapy could be used in 47% of the patients. Lymph node metastases were treated successfully in 74% of patients with a single administration of 131I calculated to deliver at least 8,500 cGy (rad). For athyrotic patients with nodal metastases only, success was achieved in 86% of patients at tumor doses of at least 14,000 cGy (rad). These success rates are equal to or better than those reported with empiric methods of 131I administration. The individualized treatment planning selectively allocates hospitalization and higher exposures to 131I to those patients who require them.

Bone scintigraphy in preschool children with lower extremity pain of unknown origin.

Small children often cannot describe the location of bone pain for parents or physicians. Bone scans were performed in 56 children under five years of age with lower extremity pain and/or gait abnormalities of unknown etiology. Patients with fever, and those known to have infection, child abuse, malignancy, and/or radiographic abnormalities were excluded. Thirty patients had abnormal bone scans. Abnormalities included evidence of hip synovitis (4), femoral head avascularity (2), various proximal femoral abnormalities (3), knee synovitis (3), toddler's fracture (1), various tibial or fibular abnormalities (4), and various abnormalities of the tarsal bones (16). Tarsal bone abnormalities included four with abnormal calcaneal uptake and nine with abnormal uptake in or adjacent to the cuboid bone. Correlative imaging studies were available for 26 sites, and focal bone findings were noted at only five locations. Tarsal bone abnormalities accounted for over half of the scintigraphic abnormalities in these preschool children with gait abnormalities. Abnormal uptake in/or adjacent to the cuboid bone was common and probably represented stress injury.

I-131 MIBG imaging after bone marrow transplantation for neuroblastoma.

Thirty-one children with stage III and IV neuroblastoma were studied with iodine-131 metaiodobenzyl-guanidine (MIBG) scintigraphy, technetium-99m medronate scintigraphy, skeletal plain radiography, and computed tomography (CT) before and after bone marrow transplantation (BMT). Twenty-six pre-BMT and 90 post-BMT studies were reviewed. Fourteen patients were alive without tumor, and one patient died at 4 months while free of tumor. I-131 MIBG scans obtained before and after BMT were negative in eight of the 15 patients. Seven had positive I-131 MIBG scans obtained before BMT that became negative after BMT. Six of 15 patients had small, questionable lesions on CT scans of the chest or abdomen that never increased in size, and the I-131 MIBG scans remained negative. Sixteen children had progressive disease or relapse, including four in whom I-131 MIBG scans showed new abnormalities, four with persistently positive I-131 MIBG scans, and three who had negative I-131 MIBG scans at relapse. Two of the 16 patients initially had small lesions seen on abdominal CT scans that were not seen on I-131 MIBG scans; mass lesions were later seen at CT in these locations. Detectable I-131 MIBG uptake in abdominal and thoracic lesions was related to the diameter of the lesion. Both I-131 MIBG scintigraphy and CT should be used to evaluate patients with neuroblastoma who have undergone BMT.

Safety and efficacy of repeated sequential administrations of Re-186(Sn)HEDP as palliative therapy for painful skeletal metastases. Initial case reports of two patients.

Single intravenous injections of 30 to 35 mCi (1,110 to 1,295 MBq) of Re-186(Sn)HEDP previously have been shown to result in palliation of painful skeletal metastases from prostate cancer. There are no reports of patients receiving repetitive Re-186(Sn)HEDP therapy. We have followed two such patients who received multiple (five to seven) injections of Re-186(Sn)HEDP at 2-month intervals. Each experienced a sustained decrease in both pain and analgesic intake. The only evident clinical or biochemical toxicity was a mild progressive decline in their total platelet counts.

Rhenium-186 hydroxyethylidene diphosphonate for the treatment of painful osseous metastases.

Rhenium-186 (tin)hydroxyethylidene diphosphonate (HEDP) is a new radiopharmaceutical that localizes in skeletal metastases in patients with advanced cancer. A single intravenous administration of approximately 34 mCi (1,258 MBq) resulted in significant improvement in pain in 33 of 43 evaluable patients (77%) following the initial injection, and in 7 of 14 evaluable patients (50%) following a second treatment. Patients responding to treatment experienced an average decrease in pain of about 60%, with one in five treatments resulting in a complete resolution of pain. The only adverse clinical reaction was the occurrence after about 10% of the administered doses of a mild, transient increase in pain within a few days following injection. Statistically significant but clinically unimportant decreases in total white blood cell counts and total platelet counts were observed within the first 8 weeks following the injection; no other toxicity was apparent. Rhenium-186(Sn)HEDP is a useful new compound for the palliation of painful skeletal metastases.

Rhenium-186(Sn)HEDP for treatment of painful osseous metastases: results of a double-blind crossover comparison with placebo.

Rhenium-186 (tin) hydroxyethylidene diphosphonate (HEDP) is a new radiopharmaceutical that simultaneously localizes in multiple skeletal metastases in patients with advanced cancer. A single intravenous administration of 30-35 mCi (1110-1295 MBq) is associated with a prompt, significant relief of osseous pain in about 80% of such patients. The efficacy of this new compound was evaluated further by utilizing a double-blind crossover comparison with 99mTc-methylene diphosphonate (MDP) as a radioactive placebo. The new rhenium compound resulted in a significantly (p less than 0.05) greater decrease in pain than did treatment with the radioactive placebo. Rhenium-186(Sn)HEDP appears to be a useful new compound for the palliation of painful skeletal metastases.

[Bone scintigraphy in mastectomized patients with and without chemotherapy]. / La scintigrafia ossea in pazienti mastectomizzate, sottoposte o no a chemioterapia.

Follow'ups were conducted on 130 mastectomized patients, periodically subjected to bone scintigraphy in addition to conventional tests. 89 of the patients had received chemotherapy and 41 had not. The results obtained show the value of scintigraphy for both accurate staging and follow-up in such patients.