Outcome of ablation of thyroid remnants with l00mCi [3.7GBq] iodine-131 in patients with thyroid cancer

Aim of the study: to determine the efficacy of a 100mCi dose for ablation of thyroid remnants; the influence of pre-therapy scanning; correlation between cervical uptake and efficacy; and the necessity of diagnostic scan for the patients with low serum Tg in the follow-up after remnant ablation

Patients and Methods: a retrospective study was conducted on 98 patients with differentiated thyroid cancer without metastases who received an ablative dose of 100mCi [3.7GBq] of iodine- 131 after total thyroidectomy

Results: six months to one year after ablation, 81/98 patients [82.6%] had a negative scan. Diagnostic scanning with 5mCi [185MBq] performed 72h or 3 months before ablation did not interfere with treatment success compared to patients not submitted to pre-therapy scanning. Pre-ablation cervical uptake values <2 %wer e associated with a higher ablation efficacy [92.8%], from 2 to 5% showed 79% success and values >5%, 57.1 % [p<0.05]. There were no significant differences between the responsive and non responsive groups in terms of age, sex, histological type or size of the primary tumor. 10.5% of the patients with low stimulated Tg [<2ng/ml] presented discrete thyroid bed uptake on follow-up diagnostic scan [<0.5%] without definitive residual disease and 79.4% had negative uptake on scan. The patients with Tg >2ng/ml presented thyroid bed [46] or ectopic [216] uptake on followup diagnostic scan

Conclusion: an ablative dose of 100mCi shows a high rate of efficacy, especially when cervical uptake is <2%, no difference was noted between patients assessed by scan within 72h or 3 months before treatment and those not scanned; follow-up diagnostic scan can be avoided in low risk patients with stimulated Tg <2ng/ml

SPECT myocardial perfusion imaging long-term prognostic value in diabetic patients with and without coronary artery disease

To determine the long-term prognostic value of SPECT myocardial perfusion imaging [MPI] for the occurrence of cardiovascular events in diabetic patients. SPECT MPI of 210 consecutive Caucasian diabetic patients were analysed using Kaplan-Meier event-free survival curves and independent predictors were determined by Cox multivariate analyses. Follow-up was complete in 200 [95%] patients with a median period of 3.0 years [0.8-5.0]. The population was composed of 114 [57%] men, age 65 +/- 10 years, 181 [90.5%] type 2 diabetes mellitus, 50 [25%] with a history of coronary artery disease [CAD] and 98 [49%] presenting chest pain prior to MPI. The prevalence of abnormal MPI was 58%. Patients with a normal MPI had neither cardiac death, nor myocardial infarction, independently of a history of coronary artery disease or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal MPI [p<0.0001], followed by history of CAD [Hazard Ratio [HR]=15.9; p=0.0001], diabetic retinopathy [HR=10.0; p=0.001] and inability to exercise [HR=7.7; p=0.02]. Patients with normal MPI had a low revascularisation rate of 2.4% during the follow up period. Compared to normal MPI, cardiovascular events increased 5.2 fold for reversible defects, 8.5 fold for fixed defects and 20.1 fold for the association of both defects. Diabetic patients with normal MPI had an excellent prognosis independently of history of CAD. On the opposite, an abnormal MPI led to a >5-fold increase in cardiovascular events. This emphasizes the value of SPECT MPI in predicting and risk-stratifying cardiovascular events in diabetic patients

Single photon emission computed tomography of technetium 99m tetrofosmin myocradial perfusion imaging in patients with sytemic lupus erythematosus: a preliminary report

This study was to evaluate the utility of single-photon emission computed tomography [SPECT] of Technetium 99m tetrofosmin [Tc-99m TF] myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus [SLE] Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardia] perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TP myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs

Early change of thyroid hormone concentration after 131I treatment in patients with solitary toxic noudule

In spite of extensive use of 131I for treatment hyperthyroidism, the results of early outcome are variable. To test whether 131 I induced necrosis causing clinical aggravation of hyperthyroidism and increasing the free thyroid Hormone concentration in the serum of patients with solitary nodule not pretreated with antithyroid drugs. Thirty consecutive patients were treated with 925 MBq 131 I. Serum concentration of thyrotropin [SH] free thyroxine [fT4], free triiodothyronine [fT3], Thyroglobuline [Tg], and interleukin-6 [IL-6] were measured A'lure and after application of 131 I. After application of 131 I no clinical worsening I was observed. FT4 and fT3 concentration did not change significantly within the first five days, whereas both of them significantly decreased after 12 days [p<0.0001]. Slight and clinically irrelevant increase in the level of the two thyroid innones was observed in 9 patients. Furthermore, we observed a prolonged increase in Tg concentration and a transient [iirrease in IL-6 concentration. Neither evidence of any clinical aggravation hyperthyroidism nor any significant increase in thyroid inrmone concentration by 131 I induced necrosis of thyroid cells was found. Therefore, the application of 131 I may be concidered as a safe and effective treatment for patients with typerthyroidism due to toxic adenoma.

Three basic patterns of changes in serum thyroid hormone levels in graves' disease during the one-year period after radioiodine therapy

Was to clarify the characteristic patterns of the thyroid hormonal changes in Graves' disease during the one-year period after [131]I therapy considering that few serial hormonal data during this period are available in the literature. The levels of serum T[3], T[4] and FT[4] before and during one year were plotted as a function of time in 86 therapy courses of 70 patients without subsequent antithyroid or steroid therapy. 35 euthyroid, 6 hypothyroid and 29 hyperthyroid states were obtained during one year after therapy. Although individual patients had individual hormonal changing patterns, 3 common basic patterns were observed from baseline to one month [early] and thereafter [late], respectively. The early patterns were a decrease in 54 [77%], a minimum change in 8 [11.5%] and an increase in 8 [11.5%]. The late patterns were a stable state after an initial decrease with a bottom followed by an increase [valley pattern] in 47 [67%], a stable state after an initial increase with a peak followed by a decrease with a bottom and a subsequent re-increase [mountain pattern] in 12 [17%] and a late stable state after a gradual slow decrease without an obvious bottom near or till one year [downhill pattern] in 11 [16%]. The bottom level and the degree of hormonal recovery from the bottom determined the stable euthyroid, hypothyroid or hyperthyroid state in 49 [86%] of 59 with the valley or mountain pattern. Most of the bottom levels [81%] and transient abnormal changes including transient hypothyroidism [93%, 13/14], peak or hyperthyroidism [85%, 11/13] and euthyroidism [67%, 10/15] appeared within 6 months. The posttherapeutic stable euthyroid, hypothyroid or hyperthyroid state could be judged from the hormonal patterns in 57% [39/68] from 2.5 to 6 months, in 18% [12/68] from 6 to 9 months and in 25% [17/68] thereafter. Although the changes in thyroid hormones are not constant in Graves' disease during one year after [131]I therapy, there are three basic patterns; valley, mountain and downhill patterns from one month after therapy. The post-therapeutic stable state can be judged by the hormonal level recovered from the bottom in most patients

Mediastinal Ga-67 uptake in patients with lymphoma following chemotherapy

Scintigraphic imaging with [67]Ga remains an important tool in evaluating the response of lymphoma to therapy. Scintigraphic characteristics of lung hilar Ga-67 uptake [HU] and their relationship with the etiology [benign vs. malignant] of the hilar lesions in lymphoma patients following chemotherapy were retrospectively investigated. A total of 161 lymphoma patients were included in the study. The presence/absence of HU and if present, symmetry/asymmetry and intensity of HU [on the basis of a 3 scale grading system] were visually and semi-quantitatively assessed on transaxial sections of thorax Ga-67 SPECT. By drawing ROIs over right and left hilum, asymmetry index [AI%] was also calculated. HU was categorized as benign or malignant depending on the radiological correlation and clinical follow-up. In the malignant group, the majority of patients [85.7%] had grade 2 or grade 3 uptake and all had asymmetric pattern. However, in the benign group, grade 1 uptake was more common [66%] and was mainly symmetric [94.6%] in appearance. AI% in the malignant group [73.7 +/- 36.6] was significantly higher than in the benign group [5.7 +/- 4.9] confirming the marked asymmetry in malignant patients. Lung HU is a common finding in patients with lymphoma following chemotherapy and frequently benign in origin, particularly if HU is symmetric and its intensity is less than that of sternum. Asymmetry index [AI%] as proposed in the present study can be used when visual assessment for the symmetry of HU is inconclusive

Estimation of post-revascularization left ventricular ejection fraction an ischemic heart disease patients by using cavity to myocardial ratio of thallium reinjection image

Background: we reported the high correlation between cavity-to-myocardial [CM] count ratio at stress and rest thallium SPECT, and stress-rest ejection fraction [EF] calculated by MUGA test, this was confirmed by others. This correlation was explained partially by the functional mass. On the other hand, two important prognostic parameters should be considered before any revascularization technique: [1] Identification of viable myocardium and its amount, [2] Prediction of EF improvement post revascularization

Aim of the Study: correlating EF[C/M] on rest-redistribution [RD] and reinjection [RI] images [EF[RD]and EF[RI]] image to actual EF pre-revascularization [EF[1]] and 1-year post revascularization EF[2]

Patients and Methods: 78 patients with CAD [68 males and 10 females with mean age of 54.2 +/- 9 years] had been subjected to [1] Standard RD-RI thallium SPECT with assessment of reversible or fixed perfusion defects and calculation of CM and consequently the EFCM at the three settings. [2]Assessment of EF by MUGA at rest pre and 1-year post revascularization EF[1] and EF[2] respectively. These patients had been subjected to revascularization either by PTCA and stent [23/78 i.e. 29.5%] or by CABG [55/78, i.e. 70.5%]

Results: out of the 1560 myocardial segments [20 segments X 78 patients], 780 [50%] segments had abnormal resting wall motion. 441/780 [56.5%] of these segments were either of normal thallium uptake or with reversible perfusion defects while the rest [43.5%] showed fixed defects. 233/441 [52.8%] of those normal uptake or reversible segments showed recovery of wall motion post revascularization [PRV] while only 29/339 [15.1%] showed similar improvements. EFRI was found higher than EFRD in 44/78 of patients, no change in 23/78 patients and worsened in 11/78 patients with total agreements of 63/78 [80.8%] with EF2. On the other hand, EFRD was matched with EF1 in 64/78 of patients. 30/64 [46.9%] showed higher EF2, 23/64 [35.9%] showed similar EF2 while 11164 [17.2%] showed lower EF2. The rest of cases 14/78 showed mismatch between EFRD and EF1 with higher values of EFRD. These patients still had higher values of EFRI and EF2 than EFRD

Conclusion: [1] Mismatch between EFRD and EF1 is an indication of presence of stunning myocardium and of good prognosis. [2] EF[RI] can be used to predict EF2 and so helps on selecting patients who can benefit from revascularization

Comparative study between low dose dobutamine echocardiography and low dose dobutamine gated single photon emission computed tomography [gSPECT] in detection of myocardial viability

The identification of severely dysfunctional but viable myocardium is of particular importance for the selection of patients with depressed left ventricular function who will benefit from coronary revascularization. Assessment of inotropic reserve with dobutamine has recently been used for this purpose. Comparing the accuracy of low-dose dobutamine [LDD] gated myocardial SPECT [gSPECT] with the accuracy of low dose dobutamine echocardiography [DSE] and resting perfusion single photon emission computed tomogra phytomography [SPECT] for the identification of viable myocardium in patients with previous myocardial infarction. Resting and low-dose dobutamine [7.5 micro g/kg/min] gated 99mTc-tetrofosmin gSPECT [TI and T2 respectively] and echocardiography [at rest and during low dose dobutamine] [R and DSE] and resting post-revascularization echocardiography [PRecho] [3 months later] were prospectively studied in 33 patients with previous myocardial infarction and severely depressed regional [function. Revascularization had been done either by CABG or PTCA for all patients. Nitroglycarine had been administered 15 min for all patients before 99m Tc-tetroforminT2. Wall motion assessment was done using 4 point score with 1 normal and 4 dyskinetic and viable tissue was diagnosed by presence of contractile response [CD] during LDD infusion in hoth echocardiography and gated SPECT using 17 segment model. Viability was defined in perfusion study by a relative Uptake 50% of tile maximum uptake. Viability in "SPECT depended upon both end-diastolic [ED] image [perfusion] and End-systolic [ES] [Contractility] images. Out of the 561 myocardial segments resting echo [R] revealed 367 segments with normal wall motion [NWM], 109 hypokinetic with CD in 83, 52 akinetic with CD in 24, 33 dyskinetic with CD in 3. Post-revascularization echo revealed 476 segments with NWM, 26 hypo, 29 ak., and 30 dyskinetic. Concerning gSPECT, out of the 194 segments with abnormal wall motion. T1 and T2 revealed 16 and 23 with normal uptake, 11 and 18 with complete reversibility, 60 and 96 with partial reversibility with overall detection of viability in 44.8%: and 70.% respectively. Degree of matching between DSE and T1 and T2 was found to be 70.6% and 80.9% respectively. Compared to PR echo., degree of matching was 69.6%, 92.3% and 85.6% for TI, T2 and DSE respectively. Pharmacological enhancement for detecting viability either by gSPECT or echocardiography. Combined Perfusion and functional assessment compensates for lower sensitivity of [99m]Tc-tetrofosmin

Low dose dobutamine with thallium reinjection in evaluation of myocardial viability

Background: although both Thallium scintigraphy and dobutamine echocardiography have been used to assess left ventricular dysfunction in patients with coronary heart disease, the mechanisms by which these two methods identify viable myocardium are different

Aim of the Study: investigate the value and limitation of low dose dobutamine during stress echocardiography and Thallium scintigraphy and the cost benefit of each of the two-non invasive tests

Patients and Methods: forty patients of CAD [31 males and 9 females] with their mean age of 49 +/- 14 years were included in the study. All of them had clinical and angiographic proof of coronary artery disease. Patients underwent clinical examination, coronary angiography, resting and dobutamine echocardiography at rate of 5 and 10 ug/kg/min, and single photon emission computed tomographic Thallium scintigraphy, stress, redistribution, reinjection images were recorded then after 24 hours low dose dobutamine [5ug/kg/min] followed by reingection image was done. The LV was divided into 20 segments for analysis of echocardiographic and Thallium images

Results: out of 800 myocardial studied segments of the 40 patients, there were 320 abnormal segments during resting echocardiography. Whereas 178 [55.6%] segments were detected to be viable by LDD echocardiography versus 154 [48.1 %] segments which were detected to be viable by Thallium imaging. On the other hand, the two methods were in agreements in detection of 125 viable segments [39.1 %] and 113 nonviable segments [35.3%] i.e. 238/320 [74.4%] segments show agreements by the two methods [P <0.05]. On adding LDD to Thallium study, the number of viable segments which could be detected by Thallium imaging increased to be 197 [61.6%] versus 178 [55.6%] segments which could be detected to be viable by LDD echocardiography i.e. Thallium become more sensitive in detection of viable myocardium than before. Furthermore the two methods were in detection of 168 viable segments [52.2%] and 113 non-viable segments [35.3%] i.e. 281/320 [87.8%] segments show agreement by the two methods [P<0.001]

Conclusion: although both Thallium scintigraphy and dobutamine echocardiography have nearly the same cost, the proportion of segments with preserved Thallium uptake [with low dose dobutamine] is greater than those showing a positive response to dobutamine Echocardiography and despite the difference is statistically insignificant, yet its is physically significant

Role of stress thallium SPECT in detection of silent myocardial ischemia in hypertensive patients with left ventricular hypertrophy [LVH]

Background: Epidemiological evidence suggests that hypertensive patients with LVH are at risk of all manifestations of CAD. Recent interest focused on symptom-free hypertensive patients with LVH, since silent myocardial ischemia [SMI] perse, comprises an increased risk for cardiovascular morbidity and mortality

Aim of the Study: To assess the inicdnece of silent myocardial ischemia in hypertensive patients with LVH

Patients and Methods: Seventy five patients with systemic hypertension had been subdivided into two main groups: Group I [hypertensive with LVH 52/75] and group II [hypertensive without LVH 23/75]. All patients were subjected to: clinical assessment, non-invasive assessment [resting. ECG, ambulatory holter, exercise thallium] and invasive assessment [coronary angiography]

Results: Group I revealed two main subgroups: one subgroup with no evidence of myocardial ischemia by etither non-invasive or invasive tests [11/52] [group IA] and second group [IB] with positive non-invasive tests for myocardial ischemia [41/52]. However, 6/41 cases showed normal coronaries [IB1] and 35/41 showed CAD [IB2]. On the other hand, group II revealed negative both noninvasive and invasive tests for ischemia

Conclusion: Positive stress thallium test in hypertensive patients with LVH is an indication of myocardial ischemia even with normal coronary angiography. Patients of group IB1 explains ECG findings with strain

Correlation between dobutamine stress echocardiography and thallium SPECT [stress-redistribution-reinjection protocol] in identifying patients with hibernating myocardium

Background: Identifying areas of myocardium with depressed but potentially reversible contractile functions may bear an important significance in the therapeutic strategy and prognosis of patients with coronary artery disease

Aim of the Study: Comparing the predictive value of dobutamine stress Echocardiography [DE] and Thallium- 201 SPECT [Stress-redistribution-reinjection] in identifying hibernating myocardium in patients with chronic CAD and severe LV dysfunction resulting in overt heart failure

Patients and Methods: Forty patients with CAD and rest LV dysfunction, already scheduled for PTCA, were screened and prospectively enrolled in the present study. They were subjected to Dobutamine stress echocardiography and stress-redistribution-reinjection thallium SPECT followed by PTCA then resting echocardiogram with correlation of pre-revascularization DSE and Thallium SPECT findings with the postrevascularization resting echocardiogram

Results: DSE could detect viable myocardium in 113/126 [78.8%] hypokinetic segments and 60/157 [38.2%] of the akinetic segments with 64.1% sensitivity and 100% specificity. On the other hand, Thallium SPECT protocol could detect viable myocardium in 225/306 [73.5%] abnormal segments with sensitivity of 100% and specificity of 70.5%. Concerning degree of matching between both tests, it was found that they agreed in 609/680 [89.6%] of the myocardial segments with p <0.001

Conclusion: Thallium myocardial perfusion is more sensitive in detection of viable myocardium while DSE is more specific in predicting recovery post-revasculization, with the conclusion that they can be used together as complementary to each other to get the most valuable information in determining therapeutic strategy and predicting prognosis

Efficacy and outcome of transmyocardial revascularization [TMR]: initial egyptian experience

In this study, 37 patients [with age 52 +/- 10.1, 31 males and 6 females] with severe coronary artery disease [CAD] and intractable angina were subjected to TMR. Nineteen patients had prior myocardial infarction [MI]. The mean angina class was 3.4 +/- 0.5. All patients were subjected to stress-redistribution reinjection [ST-RD-RI] Thallium SPECT protocol and rest 99 mTc-RBG MUGA just before, 3, 6, 9 and 12 months after TMR, aiming to assess the degree of change in perfusion in the ischemic area using semiquantitative score [I = normal and 4 = absent uptake] and to assess the function. The study concluded that TMR can be used effectively in cases of severe CAD, which could not be managed by either CABG or PTCA. Myocardial perfusion imaging is a good method to assess TMR results

Transmyocardial revascularization [TMR] versus medical treatment in patients with exensive coronary artery disease [12 months follow-up]

The aim of this study was to compare the efficacy of TMR versus medical management in cases of severe CAD not amenable to percutaneous transluminal coronary angioplasty [PTCA] or coronary artery bypass grafting [CABG]. Sixty-six patients with severe CAD were treated randomly, either by TMR or medical treatment. Accordingly, they were divided into two groups: Group 1 included 26 patients who were treated medically, while group 2 included 40 patients who were treated by TMR. All patients were subjected to clinical assessment and stress-redistribution-reinjection [ST-KD-RI] Thallium SPECT protocol pre and post TMR [3, 6, 9 and 12 months]. The study concluded that TMR has been proved to be effective in the management of severe cases of CAD concerning the quality of life and survival. Transmyocardial revascularization is a treatment option for patients with medically refractory angina who are not candidates for conventional revascularization