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Introduction: Theoretically, the bisphosphonates used to treat metastatic bone disease could influence the results of nuclear bone scans which use the structurally similar technetium 99m methylene diphosphonate (99mTc MDP). A prospective clinical study was designed to explore this hypothesis., Patients and Methods: Patients with metastatic breast cancer receiving intravenous bisphosphonate (IVBP) therapy who had > or =3 osseous lesions on nuclear bone scan were eligible. A baseline bone scan (number 1) was performed as clinically indicated and IVBP with zoledronic acid was administered within 72 hours. A second bone scan (number 2) was performed within 72 hours of zoledronic acid dosing. Both bone scans were reviewed in a blinded fashion and assessed for changes in the number and intensity of osseous lesions. Ten patients were planned to yield at least 30 lesions., Results: Ten patients were enrolled. One patient withdrew consent and 1 was excluded due to protocol deviation. Among the 8 patients were 163 assessable osseous lesions. The median time from bone scan number 1 to IVBP was 1 day (range, 1-2 days). The median time from IVBP to bone scan number 2 was 2 days (range, 1-3 days). The paired imaging showed no changes in the total number of bone metastases. One hundred sixty-one lesions were identical in both scans; in 1 patient there were 2 lesions that were discordant, one more intense, the other less intense., Conclusion: These data do not support the hypothesis that IVBP therapy interferes with bone scan results.

For patients with metastatic prostate cancer, bone is the primary site of tumor localization and the major cause of disease-related morbidity and mortality. Hormonal therapy and chemotherapy alone cannot eradicate disease harbored in bone. The delivery of radiotherapy to the reservoir of disease is an approach previously only achievable using bone-seeking radiopharmaceuticals. Now, however, with the identification of tumor-specific targets, antibodies are being used to deliver radiotherapy to these sites. In this article, we review the rationale behind this approach, the targets being explored, the radiation sources available, and the antibodies currently under clinical development.

For patients with metastatic prostate cancer, bone is the primary site of tumor localization and the major cause of disease-related morbidity and mortality. Hormonal therapy and chemotherapy alone cannot eradicate disease harbored in bone. The delivery of radiotherapy to the reservoir of disease is an approach previously only achievable using bone-seeking radiopharmaceuticals. Now, however, with the identification of tumor-specific targets, antibodies are being used to deliver radiotherapy to these sites. In this article, we review the rationale behind this approach, the targets being explored, the radiation sources available, and the antibodies currently under clinical development.

We performed a retrospective [corrected] study to evaluate the imaging potential of thallium-201 as compared with other imaging modalities in differentiating residual/recurrent tumors from post-therapy changes in patients with musculoskeletal sarcomas. 201Tl scans, magnetic resonance imaging (17), X-ray computed tomography (6) or contrast angiography (6) studies in 29 patients previously treated for musculoskeletal sarcomas were correlated with either histopathologic findings (26 patients) or 2-year clinical follow-up (three patients). All imaging studies were acquired within 2 weeks. Ratios of 201Tl tumor uptake to the contralateral (28 patients) or adjacent region of interest were calculated. When qualitative interpretation was in doubt, only those cases with a ratio of 1.5 or more were considered suggestive of recurrent of residual viable tumor tissue. Residual or recurrent tumor tissue was verified in 21 patients by biopsy. All had true-positive 201Tl scans while the other imaging modalities were true-positive in 20 and equivocal in one. In eight patients, there was no evidence of viable tumor tissue as proven by biopsy in five and long-term clinical follow-up in three. 201Tl scan was false-positive (ratio 1.5) in one patient and true-negative in seven while the other imaging modalities had four false-positives. The average 201Tl ratios were 2.8+/-1.1 in the true-positive cases and 1.3+/-0.3 in the true-negative cases. The percentage sensitivities, specificities, and accuracy for 201Tl were 100%, 87.5%, and 96.5% versus 95%, 50%, and 82.7% respectively for other imaging modalities. These results indicate that 201Tl scintigraphy is more accurate than other imaging modalities in differentiating residual/recurrent musculoskeletal sarcomas from post-therapy changes.

Unlabelled: Our goal was to determine if a healing flare response seen on bone scintigraphy occurs following chemotherapy with Taxol (paclitaxel; Bristol-Myers Squibb Co., Princeton, NJ), a novel antimicrotubule agent for metastatic breast cancer., Methods: We performed 74 bone scans on 21 females with breast cancer and bone metastases entering a Phase II trial of Taxol chemotherapy with granulocyte colony stimulating factor (G-CSF). All patients had baseline scans within 6 wk prior to therapy, after the second cycle (4-6 wk) of Taxol, and then after 6-12 mo. All bone scans were reviewed by two nuclear medicine physicians, without knowledge of the patients' clinical history. Skeletal radiographs, CT and MRI scans, as well as clinical history were compared with scan findings., Results: Seven of the 21 patients showed improvement in bone scan findings. Of these seven, three had a flare response following two cycles (4-6 wk) of Taxol, characterized by increased activity in baseline lesions and the appearance of new lesions, followed by improvement on follow-up scans. Evidence of clinical response (> or = 50% reduction in tumor mass) was seen in all of these patients. Seven patients showed no change in baseline findings on follow-up bone scans. Seven patients had post-Taxol scans showing new lesions, with no overall improvement on later follow-up., Conclusion: Flare on bone scintigraphy may be seen shortly after commencing Taxol chemotherapy. Bone scans done within the first 3 mo must be interpreted with caution and should be correlated with clinical and radiological findings to avoid inappropriate discontinuation of Taxol chemotherapy.