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Multi-drug resistance (MDR) is a major challenge in the treatment of multiple myeloma (MM). There is low sensitivity of technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) whole body scan (WBS) in the detection of active MM lesions, because (99m)Tc-MIBI is washed out from malignant cells in the presence of P-glycoprotein (PGP). The objective of the present cohort study was to evaluate of (99m)Tc-MIBI WBS in the prediction of MDR in MM patients during a course of one year follow up. Thirty four patients with MM (25 male, 9 female of mean age 54.12+/-11.46 years) entered the study. Thirteen patients had no previous history of treatment and 21 had a history of previous chemo-radiotherapy. The diagnosis and staging of the disease were based upon routine laboratory and clinical criteria like bone marrow plasma cell count, serum M component, calcium, albumin, beta(2)-microglobulin. Measurements of PGP and WBS using (99m)Tc-MIBI were performed before initialization of treatment and the response to treatment was assessed one year later. The baseline (99m)Tc-MIBI WBS were considered positive for the detection of active lesions when at least one area of non-physiologic increased activity was noted. The follow up (99m)Tc-MIBI WBS was positive for MDR when the patient had active disease but normal WBS. Our results showed that for WBS, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy in active state for the diagnosis of MDR were 38.9%, 62.5%, 70%, 31.2% and 46.1%, respectively. Also the above values for the detection of MDR, using PGP values were 50%, 50%, 69.2%, 30.8% and 50%, respectively. The relative risk of resistant to multiple regimens of chemotherapy after one year follow up in patients with negative to patients with positive (99m)Tc-MIBI WBS was 1.02 (0.60-1.72). In conclusion, we found a low sensitivity of WBS and of PGP in the detection of MDR in patients with active MM. However, both WBS and PGP have 70% and 69% positive predictive value for MDR.

Background: The ability of low dose dobutamine (LDD) has been established in exploiting the reserved contractility of ischemic myocardium. This study was designed to assess the value of a new protocol, with an additional stress imaging during LDD infusion instead of the rest images, for evaluation of coronary artery disease (CAD) and perfusion reversibility., Methods: A total of 51 patients (42 men, 9 women; 57.2 +/- 11.3 years) were included in the study and underwent three sequential steps of imaging; the first step-stress gated SPECT with Tc-99m sestamibi, immediately followed by the second step-gated SPECT during constant infusion of 7.5 microg/kg/min dobutamine and finally the third step-rest phase scan following trinitroglycerine administration in the next day. The findings were interpreted using the images in three sets of display; first vs. second step-single injection-double acquisition gated SPECT before and during LDD (SIDAGS-LDD), first vs. third step-standard stress/rest protocol, and only first step-gated stress-only SPECT. In all cases, the Visual perfusion index of each protocols were calculated by summating the premeditated 5-point scale (5: normal, 4: completely reversible, 3: partially reversible, 2: nontransmural fixed and 1: transmural fixed defects) of 17 standard myocardial segments. The accuracy as well as the correlation and agreement of protocols for detecting perfusion abnormality and corresponding reversibility were statistically analyzed., Results: Calculated sensitivity, specificity, positive predictive value, negative predictive value and accuracy regarding the presence of CAD in both SIDAGS-LDD and standard protocols were 90.9% (40/44), 71.4% (5/7), 95.2% (40/42), 55.6% (5/9) and 88.2% (45/51), respectively. The extent and localization of perfusion abnormality with the new protocol were correlated well with standard method. The estimation of reversibility, however, was considerably improved by SIDAGS-LDD, especially in those with history of previous myocardial infarction (MI)., Conclusion: Our proposed protocol demonstrates good correlation and agreement with standard method and even is superior in some cases especially for estimation of viability after MI. Regarding no need for the rest phase radiotracer injection and imaging, this protocol can be more convenient (except the need for close monitoring of the patient during LDD infusion), less time-consuming, less expensive and moreover with less radiation burden to the patients and personnel.

Background: Mustard agents are of the major chemical agents used during Iran-Iraq war. There are no reports concerning long-term cardiac effects. The aim was to assess the scintigraphic pattern of myocardial perfusion in patients intoxicated with blistering gases., Method: We analyzed myocardial perfusion scans of 22 consecutive intoxicated patients (21 male and 1 female, all < 44 years) and compared results with 14 controls. Only those patients and controls were entered whose 10-year risk of coronary artery disease (Framingham criteria) was <5%. Also only those patients were experimented upon that had currently other confirmed complications of intoxication (respiratory, cutaneous and ocular complications). All patients underwent a 1-day stress and rest protocol using (99m)Tc-MIBI. Images were assessed visually and quantitatively using Cedars Sinai program., Results: The prevalence of nonhomogeneity of uptake and left and right ventricular enlargement in both visual and quantitative analyses were higher in the mustard exposed patients than unexposed controls. The prevalence of ischemia was higher in the exposed patients (P < 0.05). Cavity to myocardium ratio, as an established and validated measure of ejection fraction, was also significantly lower in the warfare patients than the controls., Conclusion: In so far it lies in our knowledge, this is the first report concerning the scintigraphic pattern of myocardial perfusion in mustard intoxicated patients. Based on the results, the pattern of myocardial perfusion in these patients is significantly different from normal controls, which could resemble either coronary artery disease or mild cardiomyopathic changes.

Background: Left ventricular ejection fraction (EF) is a major determinant of survival in patients with coronary artery disease (CAD). Comparative accuracy of numerous modalities in calculating EF is not well investigated., Method: We compared EF as calculated by rest and post-stress Cedars automated quantitative gated SPECT (AQGS), rest and post-stress semi-automatically processed gated SPECT (MQGS), echocardiography and contrast ventriculography (LVG) to those determined by rest and post-stress cavity-to-myocardium ratio (CMR) in 109 patients. Gated SPECT was performed based on a 2-day protocol using Tc-MIBI., Results: Mean EF in LVG, echo, post-stress CMR, rest CMR, post-stress AQGS, rest AQGS, post-stress MQGS and rest MQGS were 41.8%+/-12.1, 44.8%+/-11.8, 38.1%+/-10.7, 35.7%+/-12.1, 44.5%+/-15.1, 46.9%+/-14.7, 40.1%+/-14.3 and 43.5%+/-14.3 respectively. Although significant differences were observed between some of these methods, good and excellent linear correlations were present among values (all Pearson correlations >0.63). Considering LVG as the 'gold standard', we defined two groups: EF <35% (class 1) and >35% (class 2). Discriminant analysis showed that SPECT has the ability to predict patients' classes. In 4/18 of patients with normal SPECT (on both visual and quantitative analyses, SSS <4), EF on QGS showed a significant decrease on post-stress compared with rest., Conclusion: There is a good correlation in calculating EF by LVG, QGS and echocardiography, regardless of EF value. Whenever QGS is impossible, CMR is a reliable indirect indicator of EF. Gating of both phases (and when impossible, CMR of both phases) has an additional value in diagnosis of CAD.

Technetium-99m methoxy-isobutyl-isonitrile (99mTc-MIBI) has been proposed as an in-vivo marker of various active malignant diseases. The goal of this study was to evaluate the 99mTc-MIBI whole body scintiscan for the early detection of multiple myeloma (MM), active or in remission. We have studied 43 patients with MM, 32 men and 11 women aged 52+/-10 years. Group A patients had active MM disease (29 cases) and Group B patients had MM disease in remission (14 patients). Plasma proteins, serum immuno-electrophoresis, bone marrow biopsy, whole body 99mTc-MIBI scan and serum bio-chemical tests (ESR, and serum alkaline phosphatase) were carried out in each patient for the diagnosis of active or relapsed disease, or remission. Clinical and laboratory evaluation was made by two oncologists. Scintigraphic images were interpreted by three nuclear physicians who were blinded to the patients' clinical condition. The extension scale of the lesions on scintigraphy (E-score) was categorized into E0-E3. The intensity of radiotracer uptake throughout the skeleton (I-score) was also classified from I0-I3 as compared to the intensity of myocardial uptake. All patients were followed for at least one year and reassessed by the end of the year for confirming active-relapsed disease or remission. One-way analysis of variances and Spearman correlation coefficient were used for statistical data analysis. The sensitivity, specificity, positive and negative predictive values and accuracy of the 99mTc-MIBI scan for determining active or relapsed cases were: 69%, 100%, 100%, 61% and 79%, respectively. There were significant differences in scan pattern, intensity, and extension of the lesions in patients with active-relapsed disease versus those in remission (P<0.001). It is concluded that the pattern of extension and intensity of 99mTc-MIBI uptake in MM patients is associated with disease activity. Hence, in addition to the hematological and pathological findings, the 99mTc-MIBI scan may be considered as a relatively accurate non-invasive technique for the differential diagnosis of active-relapsed from in remission MM.