Mullan, Brian P.

PURPOSE: Samarium-153 ethylene diamine tetramethylene phosphonate (153Sm-EDTMP), a bone-seeking radiopharmaceutical, provides therapeutic irradiation to osteoblastic bone metastases. Because the dose-limiting toxicity of 153Sm-EDTMP is thrombocytopenia, a dose-escalation trial using peripheral-blood progenitor cells (PBPCs) or marrow support was conducted to treat metastatic bone cancer. PATIENTS AND METHODS: Patients with locally recurrent or metastatic osteosarcoma or skeletal metastases avid on bone scan were treated with 1, 3, 4.5, 6, 12, 19, or 30 mCi/kg of 153Sm-EDTMP. RESULTS: Thirty patients were treated with 153Sm-EDTMP. Transient symptoms of hypocalcemia were seen at 30 mCi/kg. Estimates of radioisotope bound to bone surfaces and marrow radiation dose were linear with injected amount of 153Sm-EDTMP. Cytopenias also occurred in all subjects and were dose-related. At day +13 after 153Sm-EDTMP, residual whole-body radioactivity was 1% to 65% of whole-body radioactivity considered safe for PBPC infusion, 3.6 mCi. After PBPC or marrow infusion on day +14 after 153Sm-EDTMP, recovery of hematopoiesis was problematic in two patients at the 30 mCi/kg dose infused with less than 2 × 106 CD34+/kg on day +14, but not in other patients. Reduction or elimination of opiates for pain was seen in all patients. Patients had no adverse changes in appetite or performance status. CONCLUSION: 153Sm-EDTMP with PBPC support can provide bone-specific therapeutic irradiation (estimates of 39 to 241 Gy). Hematologic toxicity at 30 mCi 153Sm-EDTMP/kg requires PBPC grafts with more than 2 × 106 CD34+/kg to overcome myeloablative effects of skeletal irradiation. Nonhematologic side effects are minimal.

AbstractIntroductionFocused parathyroidectomy in primary hyperparathyroidism (1°HPT) is possible with accurate preoperative localization and intraoperative PTH monitoring (IOPTH). The added benefit of multimodal imaging techniques for operative success is unknown.MethodPatients with 1°HPT, who underwent parathyroidectomy in 2012–2014 at a single institution, were retrospectively reviewed. Only the patients who underwent the standardized multimodal imaging workup consisting of 123I/99Tc‐sestamibi subtraction scintigraphy, SPECT, and SPECT/CT were assessed.ResultsOf 360 patients who were identified, a curative operation was performed in 96 %, using pre‐operative imaging and IOPTH. Imaging analysis showed that 123I/99Tc‐sestamibi had a sensitivity of 86 % (95 % CI 82–90 %), positive predictive value (PPV) 93 %, and accuracy 81 %, based on correct lateralization. SPECT had a sensitivity of 77 % (95 % CI 72–82 %), PPV 92 % and accuracy 72 %. SPECT/CT had a sensitivity of 75 % (95 % CI 70–80 %), PPV of 94 %, and accuracy 71 %. There were 3 of 45 (7 %) patients with negative sestamibi imaging that had an accurate SPECT and SPECT/CT. Of 312 patients (87 %) with positive uptake on sestamibi (93 % true positive, 7 % false positive), concordant findings were present in 86 % SPECT and 84 % SPECT/CT. In cases where imaging modalities were discordant, but at least one method was true‐positive, 123I/99Tc‐sestamibi was significantly better than both SPECT and SPECT/CT (p < 0.001). The inclusion of SPECT and SPECT/CT in 1°HPT imaging protocol increases patient cost up to 2.4‐fold.Conclusion123I/99Tc‐sestamibi subtraction imaging is highly sensitive for preoperative localization in 1°HPT. SPECT and SPECT/CT are commonly concordant with 123I/99Tc‐sestamibi and rarely increase the sensitivity. Routine inclusion of multimodality imaging technique adds minimal clinical benefit but increases cost to patient in high‐volume setting.

Tc-99m ethyl cysteinate diethylester (ECD) and Tc-99m hexamethyl propylene amine oxime (HMPAO) are commonly used for single-photon emission computed tomography (SPECT) studies of a variety of neurologic disorders. Although these tracers have been very helpful in diagnosing and guiding treatment of neurologic disease, data describing the distribution and laterality of these tracers in normal resting brain are limited. Advances in quantitative functional imaging have demonstrated the value of using resting studies from control populations as a baseline to account for physiologic fluctuations in cerebral perfusion. Here, we report results from 30 resting Tc-99m ECD SPECT scans and 14 resting Tc-99m HMPAO scans of normal volunteers with no history of neurologic disease. Scans were analyzed with regions of interest and with statistical parametric mapping, with comparisons performed laterally (left vs. right), as well as for age, gender, and handedness. The results show regions of significant asymmetry in the normal controls affecting widespread areas in the cerebral hemispheres, but most marked in superior parietotemporal region and frontal lobes. The results have important implications for the use of normal control SPECT images in the evaluation of patients with neurologic disease.