The Importance of Quality in Ventilation-Perfusion Imaging.

As the health care environment continues to change and morph into a system focusing on increased quality and evidence-based outcomes, nuclear medicine technologists must be reminded that they play a critical role in achieving high-quality, interpretable images used to drive patient care, treatment, and best possible outcomes. A survey performed by the Quality Committee of the Society of Nuclear Medicine and Molecular Imaging Technologist Section demonstrated that a clear knowledge gap exists among technologists regarding their understanding of quality, how it is measured, and how it should be achieved by all practicing technologists regardless of role and education level. Understanding of these areas within health care, in conjunction with the growing emphasis on evidence-based outcomes, quality measures, and patient satisfaction, will ultimately elevate the role of nuclear medicine technologists today and into the future. The nuclear medicine role now requires technologists to demonstrate patient assessment skills, practice safety procedures with regard to staff and patients, provide patient education and instruction, and provide physicians with information to assist with the interpretation and outcome of the study. In addition, the technologist must be able to evaluate images by performing technical analysis, knowing the demonstrated anatomy and pathophysiology, and assessing overall quality. Technologists must also be able to triage and understand the disease processes being evaluated and how nuclear medicine diagnostic studies may drive care and treatment. Therefore, it is imperative that nuclear medicine technologists understand their role in the achievement of a high-quality, interpretable study by applying quality principles and understanding and using imaging techniques beyond just basic protocols for every type of disease or system being imaged. This article focuses on quality considerations related to ventilation-perfusion imaging. It provides insight on appropriate imaging techniques and protocols, true imaging variants and tracer distributions versus artifacts that may result in a lower-quality or misinterpreted study, and the use of SPECT and SPECT/CT as an alternative providing a high-quality, interpretable study with better diagnostic accuracy and fewer nondiagnostic procedures than historical planar imaging.

Cost of care for malignant and benign renal masses.

BACKGROUND: Limitations of current diagnotic techniques may allow some patients with presumed renal cell carcinoma (RCC) to undergo nephrectomy without definitive confirmation of malignancy. OBJECTIVES: To confirm previous estimates of postnephrectomy renal mass diagnosis and to assess the economic impact of nephrectomy. METHODS: This retrospective cohort analysis identified commercial enrollees who underwent nephrectomy with a diagnosis of RCC between July 1, 2000, and March 30, 2008. Study subjects were stratified based on medical claims for benign or malignant disease after the nephrectomy date. Cohorts were compared on resource utilization before and after nephrectomy, occurrence of postsurgical complications, and associated 1-year costs of care. RESULTS: Of 10,404 patients undergoing nephrectomy for presumed RCC, 1613 (15.5%) were subsequently identified as having benign disease, despite median presurgical diagnostic expenditures of $1311 per patient (interquartile range [IQR], $467-$2606). Median expenditures for the 12 months postnephrectomy were $26,920 per patient (IQR, $16,851-$46,982) for those with malignant disease and $23,951 per patient (IQR, $14,873-$38,190) for those with benign disease (P<.0001). For patients with benign disease, 17.5% experienced a postsurgical adverse event, resulting in a 1.5-fold increase in expenditures (median $31,838 per patient for those with event vs $22,770 per patient for those without event; P<.0001). CONCLUSIONS: In this study, approximately 1 in 6 patients were found to have a benign renal mass postnephrectomy. Given the risk of surgical complications and related economic consequences, methods for better identifying malignant versus benign disease prior to surgery could provide significant benefits to patients and payers.

Dose escalation study of no-carrier-added 131I-metaiodobenzylguanidine for relapsed or refractory neuroblastoma: new approaches to neuroblastoma therapy consortium trial.

UNLABELLED: (131)I-metaiodobenzylguanidine (MIBG) is specifically taken up in neuroblastoma, with a response rate of 20%-37% in relapsed disease. Nonradioactive carrier MIBG molecules inhibit uptake of (131)I-MIBG, theoretically resulting in less tumor radiation and increased risk of cardiovascular toxicity. Our aim was to establish the maximum tolerated dose of no-carrier-added (NCA) (131)I-MIBG, with secondary aims of assessing tumor and organ dosimetry and overall response. METHODS: Eligible patients were 1-30 y old with resistant neuroblastoma, (131)I-MIBG uptake, and cryopreserved hematopoietic stem cells. A diagnostic dose of NCA (131)I-MIBG was followed by 3 dosimetry scans to assess radiation dose to critical organs and soft-tissue tumors. The treatment dose of NCA (131)I-MIBG (specific activity, 165 MBq/µg) was adjusted as necessary on the basis of critical organ tolerance limits. Autologous hematopoietic stem cells were infused 14 d after therapy to abrogate prolonged myelosuppression. Response and toxicity were evaluated on day 60. The NCA (131)I-MIBG was escalated from 444 to 777 MBq/kg (12-21 mCi/kg) using a 3 + 3 design. Dose-limiting toxicity (DLT) was failure to reconstitute neutrophils to greater than 500/µL within 28 d or platelets to greater than 20,000/µL within 56 d, or grade 3 or 4 nonhematologic toxicity by Common Terminology Criteria for Adverse Events (version 3.0) except for predefined exclusions. RESULTS: Three patients each were evaluable at 444, 555, and 666 MBq/kg without DLT. The dose of 777 MBq/kg dose was not feasible because of organ dosimetry limits; however, 3 assigned patients were evaluable for a received dose of 666 MBq/kg, providing a total of 6 patients evaluable for toxicity at 666 MBq/kg without DLT. Mean whole-body radiation was 0.23 mGy/MBq, and mean organ doses were 0.92, 0.82, and 1.2 mGy/MBq of MIBG for the liver, lung, and kidney, respectively. Eight patients had 13 soft-tissue lesions with tumor-absorbed doses of 26-378 Gy. Four of 15 patients had a complete (n = 1) or partial (n = 3) response, 1 had a mixed response, 4 had stable disease, and 6 had progressive disease. CONCLUSION: NCA (131)I-MIBG with autologous peripheral blood stem cell transplantation is feasible at 666 MBq/kg without significant nonhematologic toxicity and with promising activity.

Iodofiltic acid I 123 (BMIPP) fatty acid imaging improves initial diagnosis in emergency department patients with suspected acute coronary syndromes: a multicenter trial.

OBJECTIVES: The aim of this study was to assess the performance of beta-methyl-p-[123I]-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) to detect acute coronary syndromes (ACS) in emergency department patients with chest pain. BACKGROUND: Emergency department diagnosis of chest pain is problematic, often requiring prolonged observation and stress testing. BMIPP SPECT detects abnormalities in fatty acid metabolism resulting from myocardial ischemia, even many hours after symptom cessation. METHODS: Emergency department patients with suspected ACS were enrolled at 50 centers. Patients received 5 mCi BMIPP within 30 h of symptom cessation. BMIPP SPECT images were interpreted semiquantitatively by 3 blinded readers. Initial clinical diagnosis was based on symptoms, initial electrocardiograms, and troponin, whereas the final diagnosis was based on all available data (including angiography and stress SPECT) but not BMIPP SPECT. Final diagnoses were adjudicated by a blinded committee as ACS, intermediate likelihood of ACS, or negative for ACS. RESULTS: A total of 507 patients were studied and efficacy was evaluated in 448 patients with sufficient data. The sensitivity of BMIPP by 3 blinded readers for a final diagnosis of ACS and intermediate likelihood of ACS was 71% (95% confidence interval [CI]: 64% to 79%), 74% (95% CI: 68% to 81%), and 69% (95% CI: 62% to 77%); the corresponding specificity of BMIPP was 67% (95% CI: 61% to 73%), 54% (95% CI: 48% to 60%), and 70% (95% CI: 64% to 76%). Compared with the initial diagnosis alone, BMIPP+initial diagnosis increased sensitivity from 43% to 81% (p<0.001), negative predictive value from 62% to 83% (p<0.001), and positive predictive value from 41% to 58% (p<0.001), whereas specificity was unchanged (61% to 62%, p=NS). CONCLUSIONS: The addition of BMIPP data to the initially available clinical information adds incremental value toward the early diagnosis of an ACS, potentially allowing determination of the presence or absence of ACS to be made earlier in the evaluation process. (Safety and Efficacy Iodofiltic Acid I 123 in the Treatment of Acute Coronary Syndrome [Zeus-ACS]; NCT00514501).

90Y-edotreotide for metastatic carcinoid refractory to octreotide.

PURPOSE: Metastatic carcinoid is an incurable malignancy whose symptoms, such as diarrhea and flushing, can be debilitating and occasionally life-threatening. Although symptom relief is available with octreotide, the disease eventually becomes refractory to octreotide, leaving no proven treatment options. The goal of this study was to evaluate the clinical effect of using (90)Y-edotreotide to treat symptomatic patients with carcinoid tumors. PATIENTS AND METHODS: Patients enrolled had metastatic carcinoid, at least one sign/symptom refractory to octreotide, and at least one measurable lesion. Study treatment consisted of three cycles of 4.4 GBq (120 mCi) (90)Y-edotreotide each, once every 6 weeks. RESULTS: Ninety patients were enrolled in the study. Using Southwest Oncology Group tumor response criteria, 67 (74.%) of 90 patients (95% CI, 65.4% to 83.4%) were objectively stable or responded. A statistically significant linear trend toward improvement was demonstrated across all 12 symptoms assessed. Median progression-free survival was significantly greater (P = .03) for the 38 patients who had durable diarrhea improvement than the 18 patients who did not (18.2 v 7.9 months, respectively). Adverse events (AEs) were reported in 96.7% (87 of 90) of patients. These AEs consisted primarily of reversible GI events (76 of 90), which could be caused in part by concomitant administration of amino acid solution given to reduce radiation exposure to the kidneys. There was one case each of grade 3 oliguria and grade 4 renal failure, each lasting 6 days. CONCLUSION: (90)Y-edotreotide treatment improved symptoms associated with malignant carcinoid among subjects with no treatment alternatives. Treatment was well-tolerated and had an acceptable expected AE profile.

Radiation dosimetry, pharmacokinetics, and safety of ultratrace Iobenguane I-131 in patients with malignant pheochromocytoma/paraganglioma or metastatic carcinoid.

This is a first of many phase 1 study of Ultratrace Iobenguane I-131 (Ultratrace 131I-MIBG; Molecular Insight Pharmaceuticals, Inc., Cambridge, MA). High-specific-activity Ultratrace 131I-MIBG may provide improved efficacy and tolerability over carrier-added 131I-MIBG. We investigated the pharmacokinetics (PK), radiation dosimetry, and clinical safety in 11 patients with confirmed pheochromocytoma/paraganglioma (Pheo) or carcinoid tumors. A single 5.0-mCi (185 MBq) injection of Ultratrace 131I-MIBG, supplemented with 185 microg of unlabeled MIBG to simulate the amount of MIBG anticipated in a therapeutic dose, was administered. Over 120 hours postdose, blood and urine were collected for PK, and sequential whole-body planar imaging was performed. Patients were followed for adverse events for 2 weeks. Ultratrace 131I-MIBG is rapidly cleared from the blood and excreted in urine (80.3% +/- 2.8% of dose at 120 hours). For a therapeutic administration of 500 mCi (18.5 GBq), our estimate of the projected dose is 1.4 Gy for marrow and 10.4 Gy for kidneys. Safety results showed 12 mild adverse events, all considered unrelated to study drug, in 8 of 11 patients. These findings support the further development of Ultratrace 131I-MIBG for the treatment of neuroendocrine tumors, such as metastatic Pheo and carcinoid.

Pharmacokinetics and safety of gadobenate dimeglumine (multihance) in subjects with impaired liver function.

RATIONALE AND OBJECTIVES: To characterize the pharmacokinetics of gadolinium and to evaluate the safety of gadobenate dimeglumine (Gd-BOPTA) compared with placebo, in subjects with impaired liver function. METHODS: Volunteer adult subjects with hepatic impairment (Child-Pugh classification B or C) received, randomly and in double-blind fashion, either 0.1 mmol/kg gadobenate dimeglumine (n = 11) or placebo (n = 5) by intravenous injection. Blood and urine gadolinium concentrations were determined by ICP-AES and data were analyzed by compartmental and noncompartmental modeling. A full safety evaluation was performed. No magnetic resonance imaging was performed. RESULTS: A bi-exponential model fit the gadolinium blood concentration-time data for 10 of 11 subjects administered Gd-BOPTA. The mean (CV%) distribution and elimination half-lives for these subjects were 0.18 (71.9) and 2.18 (44.2) hours, respectively. Non-parametric analysis of all 11 subjects revealed a mean (CV%) area under the curve [0-inf] of 138 (41.9) microg(Gd).h/mL. Mean (CV%) values for blood clearance, steady-state volume of distribution, and renal clearance were 172 (36.0) mL/minute, 22.9 (16.7) L, and 142 (49.0) mL/minute, respectively. A mean (CV%) of approximately 80% (24.5) of the administered dose was excreted in urine during 60 to 72 hours. No safety concerns were apparent. CONCLUSION: Hepatic impairment did not modify the pharmacokinetics of gadobenate dimeglumine compared with values reported elsewhere for healthy subjects. The contrast agent was well tolerated and safe with an overall incidence of adverse events comparable to that of placebo.