Preoperative Single-photon Emission Computed Tomography Research Articles

Virtual reality-based training and pre-operative planning for head and neck sentinel lymph node biopsy

ObjectiveSentinel lymph node biopsy (SLNB) is crucial for managing head and neck skin cancer. However, variable lymphatic drainage can complicate SLN detection when using Single-Photon Emission Computed Tomography (SPECT) or lymphoscintigraphy. Virtual Reality (VR) can contribute to pre-operative planning by simulating a realistic 3D model, which improves orientation. VR can also facilitate real-patient training outside the operating room. This study explored using a VR platform for pre-operative planning in head and neck skin cancer patients undergoing SLNBs and assessed its value for residential training. Materials and methodsIn this prospective technology pilot study, attending surgeons and residents who performed 21 SLNB operations on patients with head and neck skin cancers (81% males, mean age 69.2 ± 11.3) used a VR simulation model based on each patient's pre-operative SPECT scan to examine patient-specific anatomy. After surgery, they completed a questionnaire on the efficiency of the VR simulation as a pre-operative planning tool and training device for residents. ResultsThe attending surgeons rated the VR model's accuracy at 8.3 ± 1.6 out of 10. Three-quarters (76%) of residents reported increased confidence after using VR. The physicians rated the platform's contribution to residents' training at 7.4 ± 2.1 to 8.9 ± 1.3 out of 10. ConclusionA VR SLNB simulation can accurately portray marked sentinel lymph nodes. It was rated high as a surgical planning and teaching tool among attending surgeons and residents alike and may play a role in pre-operative planning and resident training. Further studies are needed to explore its applications in practice.

178 Adjunctive Use of Preoperative SPECT Imaging for Evaluation of Chronic Cervical and Lumbar Pain

INTRODUCTION: Radionuclide bone scintigraphy with single photon emission computed tomography (SPECT) has been used to evaluate foci of inflammation within the spinal axis. Studies have reported its use as an tool for recognition of pain foci and spondolytic change. As an adjunctive test SPECT may prove to give valuable insight into areas of focal inflammation within the spinal axis and therefore serve as a tool for guiding operative and nonoperative intervention in patients with degenerative spine disease. METHODS: We performed a retrospective case series to identify patients with chronic neck/back pain who underwent SPECT imaging for pre-operative evaluation. Patient demographics, area of uptake, correlation with pain morphology, type of intervention, and degree of symptom resolution were quantified. Patients were excluded if they had prior surgery/intervention at the level corresponding to symptomatology. RESULTS: Thirty-two patients underwent SPECT imaging. Patients presented with axial back pain (97%) and radicular pain (42%). Radiotracer uptake was seen in facet and/or disc space at the level of symptomology in 44% of patients, facet alone (22%), disc space alone (22%), and uncovertebral joint (12%). Interventions included facet injections (26 patients), basovertebral plexus ablation (7 patients), and open/minimally-invasive surgery (9 patients). Two patients underwent anterior cervical discectomy and the remainder of our cohort underwent lumbar instrumentation and fusion. All but one surgical patient (97%) reported significant relief of symptoms. CONCLUSIONS: SPECT imaging may be useful adjunctive imaging modality to evaluate for focal areas of inflammation not readily observed on MRI or CT. Our experience suggests that SPECT can identify areas of pathology that responsive to various types of intervention.

Efficacy of arterial spin labeling magnetic resonance imaging with multiple post-labeling delays to predict postoperative cerebral hyperperfusion in carotid endarterectomy

ABSTRACT Introduction: Cerebral hyperperfusion (CHP) syndrome is one of the most deleterious complications after carotid endarterectomy (CEA). Arterial spin labeling (ASL) is a promising non-invasive method to evaluate various hemodynamic parameters in cerebrovascular diseases. The aim of this study was to clarify whether ASL with multiple post-labeling delays (PLDs) can predict postoperative CHP after CEA. Methods: Sixty-one patients with carotid artery stenosis treated by CEA were retrospectively analyzed. The asymmetry index of the preoperative CBF was obtained from ASL using 3 PLDs (1525 ms, 2025 ms, and 2525 ms) and single-photon emission computed tomography (SPECT). Cerebrovascular reactivity (CVR) was measured from SPECT with acetazolamide challenge. The slope of the regression line obtained from the asymmetry index of three PLDs was defined as the slope index. Results: The CHP phenomenon was observed in seven patients (11.5%), one of whom developed CHP syndrome (1.6%). Using the CHP phenomenon as a reference standard, the area under the receiver operating characteristics (ROC) was 0.68 for the asymmetry index of the preoperative SPECT, 0.71 for the asymmetry index of the preoperative ASL,0.73 for CVR, and 0.78 for the slope index. Using the cutoff value obtained by ROC analysis, the slope index demonstrated a sensitivity of 85%, specificity of 74%, positive predictive value of 30% and the negative predictive value of 98% for predicting CHP. Conclusions: The slope index calculated by ASL with multiple PLDs is a useful screening tool to predict postoperative CHP after CEA.

The value of myocardial perfusion imaging in screening coronary artery disease before kidney transplantation.

The value of myocardial single-photon emission computed tomography (SPECT) in pre-transplant evaluation of kidney transplant recipients is controversial. We assessed whether myocardial SPECT predicts major adverse cardiac events (MACE) and determined whether SPECT findings affected transplant recipients' medical and invasive treatment. We analyzed 301 patients referred for myocardial SPECT before kidney transplantation and combined the results with information from patient files and the Transplantation Registry. During the median follow-up time of 96months (IQR 70.75-118.25months), the incidence of MACE was higher in patients (n=37) with severely abnormal SPECT (>10% reversible perfusion defect) than in patients (n=35) with mildly abnormal or normal SPECT (51.4%, 29.4%, and 27.0%, respectively, P=.011). Severely abnormal SPECT findings predicted long-term MACE in a univariable analysis but not after adjusting for other risk factors. Following SPECT, 29 patients (9.6%) underwent coronary angiography and 14 (4.6%) were revascularized. New antithrombotic or statin medication was prescribed to 7.3% of patients with ischemia in SPECT. Kidney transplantation patients are at high long-term risk of MACE even with normal preoperative myocardial SPECT. Abnormal SPECT did not predict MACE when adjusted for other risk factors. Minority of the patients underwent coronary revascularization or had changes in preventive medication before transplantation.

Prediction of the Cerebral Hyperperfusion Phenomenon after Carotid Endarterectomy Using a Transit Time Flowmeter.

The purpose of this study was to investigate the relationship between the cerebral hyperperfusion phenomenon (CHP) and carotid artery flow volume as measured by a transit time flowmeter during carotid endarterectomy (CEA). We retrospectively investigated 74 patients who underwent both transit time flowmetry and single photon emission computed tomography (SPECT). The flow volumes of the internal carotid artery (ICA) before and after the endarterectomy were recorded during surgery as the pre- and the post-ICA (mL/min), respectively. We defined the difference between the pre- and the post-ICA as the ΔIC (mL/min). Two independent board-certified neurosurgeons analyzed the asymmetry index (affected side/contralateral side) of regional qualitative cerebral blood flow before and after the CEA respectively. We defined the CHP as an excessive increase in this asymmetry index between preoperative and postoperative SPECT. The CHP was observed in five of the 74 patients (6.8%). The pre-ICA of the CHP cases was significantly lower than that of the non-CHP cases (in mL/min, median 29 vs. 97; P = 0.01). The ΔIC of the CHP cases was significantly higher than that of the non-CHP cases (in mL/min, median 154 vs. 50; P = 0.002). The cut-off value of the ΔIC was 81 mL/min (sensitivity 100%, specificity 78.3%, area under the curve 0.912). The findings of this study suggest that the ΔIC is associated with the CHP. The transit time flowmeter is useful to predict the CHP during surgery.

1273Efficacy and safety of prehabilitation before coronary artery bypass grafting

Abstract Purpose To evaluate the effectiveness and safety of high intensity prehabilitation included in the routine preoperative management of patients with coronary artery disease (CAD) for elective on-pump coronary artery bypass grafting (CABG). Methods 38 male patients with stable CAD referred to on-pump CABG who either underwent prehabilitation or not were assigned into two study groups. Group 1 patients (n=20, the mean age 61.5 years [55; 64] underwent high intensity treadmill exercises. Group 2 patients (n=18, the mean age 62.0 years [56; 65]) underwent routine preoperative management without prehabilitation. Treadmill exercises in Group 1 patients were performed under hemodynamic control and ECG monitoring. The training power of a workout was calculated based on cardiopulmonary exercise test (CPET) performed before preoperative exercises, and was estimated as 80% of the maximal power obtained during the exercise test. Adenosine loading single-photon emission computed tomography (SPECT) was used to measure the parameters of myocardial perfusion before preoperative exercises and on days 5–7 after CABG in both study groups. Biochemical markers of myocardial damage (troponin I, NT-proBNP) were measured before the training session, after it and then in the postoperative period to assess the safety of the prehabilitation program. In-hospital postoperative complications were recorded and analyzed. Results Both study groups were comparable in the main clinical and demographic parameters, intraoperative clinical parameters as well as in preoperative CPET and SPECT results. There were no cases of complications during prehabilitation. The analysis of myocardial perfusion parameters demonstrated that patients who had undergone prehabilitation had significantly higher accumulation of radiopharmaceuticals than those in the control group in basal segments (74.9±3.98% vs. 70.3±7.40% p=0.04), middle (86.7±5.24% vs. 79.6±10.43%, p=0.03) and apical (85.8±5.03% vs. 79.0±8,67%, p=0.02) myocardium. The stress-induced ischemia (SDS) was less pronounced in Group 1 compared to Group 2 (0 scores and 0.9±0.53 scores, respectively, p=0.04). Myocardial perfusion defect significantly decreased during the infusion of adenosine (SSS) (p=0.013), as well as the SDS index (p=0.018) in the prehabilitation group after CABG compared with the baseline. Both groups had similar serum troponin I levels within the normal range before and after CABG. NT-pro BNP levels significantly increased in the postoperative period in patients who did not undergo prehabilitation (p=0.003). Patients who underwent prehabilitation had a significantly lower incidence of the in-hospital postoperative complications compared to patients without exercise trainings (p=0.002). Conclusion The inclusion of high intensity preoperative exercises in the routine preoperative management of patients referred to elective CABG is safe and effective method of cardioprotection improving surgical outcomes.

Effectiveness of Staged Angioplasty for Avoidance of Cerebral Hyperperfusion Syndrome After Carotid Revascularization

A multicenter, retrospective review was performed from October 2007 to March 2014. During this period, 523 patients (8%) from 44 Japanese centers were considered at high risk of cerebral hyperperfusion syndrome by the findings from single-photon emission computed tomography (SPECT) or other studies. Of 530 atherosclerotic lesions, 428 were treated by single-stage carotid artery stenting (CAS) and 102 by carotid artery angioplasty using a 3-mm-diameter balloon, followed by delayed, or staged, CAS (SAP) 2 to 4 weeks later. The preoperative mean carotid artery stenosis and SPECT parameters were worse in the SAP group than in the single-stage CAS group. All cases were performed via the transfemoral approach and embolic protection devices. The rate of cerebral hyperperfusion syndrome was significantly less in the SAP group (4%) compared with the single-stage CAS group (10%; P = .47). Multivariate analysis showed that SAP was negatively related to hyperperfusion syndrome. The composite rate of transient ischemic attack and ischemic stroke was about the same in both groups (9%). Carotid angioplasty followed by staged CAS might be effective for preventing hyperperfusion syndrome.

Reduced Hypoxic Tissue and Cognitive Improvement after Revascularization Surgery for Chronic Cerebral Ischemia

Background: Hypoxic but viable neural tissue is seen on 1-(2–¹⁸F-fluoro-1-[hydroxymethyl]ethoxy) methyl-2-nitroimidazole (¹⁸F-FRP170) positron emission tomography (PET) in patients with chronic cerebral ischemia with a combination of misery perfusion and moderately reduced oxygen metabolism. Cognitive function sometimes improves after revascularization surgery in patients with chronic cerebral ischemia. Objectives: We used brain perfusion single-photon emission computed tomography (SPECT) and ¹⁸F-FRP170 PET to determine whether hypoxic tissue was reduced following the restoration of cerebral perfusion after carotid endarterectomy (CEA) in patients with severe stenosis of the cervical internal carotid artery (ICA) and whether the reduction in hypoxic tissue was associated with cognitive improvement. Method: Eighteen patients with abnormally reduced cerebral blood flow (CBF) in the affected cerebral hemispheres on preoperative brain perfusion SPECT ­underwent CEA. They underwent ¹⁸F-FRP170 PET and neuropsychological tests preoperatively and 6 months postoperatively. Brain perfusion SPECT was also performed 6 months postoperatively. Regions of interest were placed in the bilateral middle cerebral artery territories on SPECT and PET images, and the ratio of values in the affected versus contralateral hemispheres was calculated. Results: The CBF ratio (p = 0.0006) and ¹⁸F-FRP170 ratio (p = 0.0084) were significantly increased and reduced, respectively, after surgery compared to the corresponding ratios before surgery. The difference in the ¹⁸F-FRP170 ratio (postoperative – preoperative value) was negatively correlated with the difference in the CBF ratio (ρ = –0.695; p = 0.0009). The difference in the ¹⁸F-FRP170 ratio was significantly lower in patients with postoperative improved cognition compared to that in those without (p = 0.0007). The area under the receiver operating characteristics curve for the difference in the ¹⁸F-FRP170 ratio for detecting postoperative improved cognition was significantly greater than that for the difference in the CBF ratio (difference between areas, 0.278; p = 0.0248). Conclusions: Hypoxic tissue is reduced following the restoration of cerebral perfusion with revascularization surgery in patients with severe atherosclerotic stenosis of the cervical ICA. The reduction in hypoxic tissue is associated with cognitive improvement in such patients.

Single photon emission computed tomography (SPECT) for planning of surgical tactics in advanced liver resections

Aim. To determine the indications for staged treatment in planning of advanced liver resections using SPECT. Material and methods. There were 26 patients for the period 2007–2016 who required advanced liver resections at the surgical clinic of the Botkin Hospital. Anatomic FLR (aFLR) was less than 30% in all cases that is an indication for right portal branch embolization. Two-stage treatment has been applied in 15 patients (group 1) for the period 2007–2014. Preoperative examination has included SPECT since 2015. Indication for two-stage treatment was functioning FLR (fFLR) less than 30% (group 2). The second group included 11 patients. Results. In the first group (n = 15), all patients underwent right portal branch embolization. Nine of them underwent surgery including advanced right-sided hemihepatectomy in 5 cases and right-sided hemihepatectomy in 4 cases.Acute postoperative liver failure occurred in 1 (11.1%) patient (ISGLS class A). In the second group (n = 11) need for portal embolization was determined after SPECT. In 5 patients fFLR was over 30%. Thus, advanced right-sided hemihepatectomy and conventional right-sided hemihepatectomy were carried out in 2 and 3 cases, respectively. Six patients had fFLR less than 30% and two-stage approach was indicated. Five patients underwent radical surgery: advanced right-sided hemihepatectomy and conventional right-sided hemihepatectomy were carried out in 2 and 3 cases, respectively. There were no cases of acute postoperative liver failure and mortality in this group. Conclusion. Preoperative SPECT is able to predict high risk of acute postoperative liver failure after advanced liver resection. Therefore, certain measures for prevention of this complication may be considered.

Objective evaluation of cerebrovascular reactivity for acetazolamide predicts cerebral hyperperfusion after carotid artery stenting: Comparison with region of interest methods

Background and purposeHemodynamic impairments are considered risk factors of cerebral hyperperfusion after carotid artery stenting (CAS); measurement by Single-photon emission computed tomography (SPECT) using a subjective region of interest (ROI) method lacks consistency and reproducibility. Materials and methodsThe present study compared objective perfusion analysis (stereotactic extraction estimation [SEE] method) with the ROI method for preoperative SPECT to predict the hyperperfusion phenomenon (HPP) after CAS. Preoperative resting asymmetry index (cerebral blood flow [CBF] ratio from the affected to unaffected hemisphere) and cerebrovascular reactivity (CVR) to acetazolamide were measured by N-isopropyl-p-[123I]-iodoamphetamine SPECT using the SEE and ROI method in 84 patients. CBF was also measured the day after CAS. Perfusion data with the highest area under the curve (AUC) by receiver-operating characteristic (ROC) analysis was considered a perfusion risk factor of HPP. Multivariate analyses for clinical characteristics and perfusion risk factors were performed to determine predictors of HPP. ResultsThe HPP was observed in 10 patients (11.9%). Female sex, contralateral stenosis, and degree of stenosis were significantly associated with HPP development on univariate analysis, and symptomatic stenosis was not found to be a significant factor. On SPECT analysis, CVR in the MCA area by SEE method had the highest AUC (0.981). Multivariate analysis showed that CVR in the MCA area was a significant predictor of HPP (P=0.041). To predict hyperperfusion, the ROC curve of the CVR showed a cutoff value of –0.60%, sensitivity of 94.6%, and specificity of 100% (P<0.001). ConclusionsObjective SEE method had better a predictive capability than ROI method to identify risk of hyperperfusion after CAS.

Feasibility of sentinel lymph node dissection using Tc-99m phytate in papillary thyroid carcinoma

PurposeVarious methods of sentinel lymph node (SLN) biopsy in thyroid cancer have been introduced. Tc-99m phytate as a radiotracer has been successfully utilized for SLN biopsy in breast, cervix, and endometrial cancer. We assessed the feasibility of SLN dissection using Tc-99m phytate in papillary thyroid carcinoma (PTC).MethodsSeventeen patients with PTC were prospectively enrolled. Ultrasound-guided peritumoral injection of 55.5 MBq Tc-99m phytate in 0.25-mL normal saline was performed. Preoperative single-photon emission-computed tomography (SPECT) and intraoperative gamma-probe were used for SLN detection during operation.ResultsIdentification rate of SLNs was 70.6% (12 of 17) with SPECT, and 88.2% (15 of 17) with gamma-probe. Combined SPECT and gamma-probe had identification rates of 88.2% (15 of 17). Identification rates of SLNs in central LN compartments were 82.4% (14 of 17) and 41.2% (7 of 17) in lateral LN compartments. Overall sensitivity, specificity, positive predictive value, and negative predictive value of the results of SLN biopsy were 91.6%, 100%, 88.4%, and 100%, respectively. Eight patients (47.1%) had metastasis in SLNs; all patients had SLN metastasis in the central compartment and 2 patients had SLN metastasis in both the central and lateral compartments.ConclusionCombined SPECT and gamma-probe could detect SLNs with an 88.2% identification rate in PTC. SLN biopsy using Tc-99m phytate is technically feasible. Further investigation is warranted for clinical application of Tc-99m phytate in PTC.

Cerebral Hyperperfusion after Revascularization Inhibits Development of Cerebral Ischemic Lesions Due to Artery-to-Artery Emboli during Carotid Exposure in Endarterectomy for Patients with Preoperative Cerebral Hemodynamic Insufficiency: Revisiting the "Impaired Clearance of Emboli" Concept.

The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA. Microembolic signals (MES) were identified using transcranial Doppler during carotid exposure. Diffusion-weighted magnetic resonance imaging (DWI) was performed within 24 h after surgery. Of 32 patients with a combination of reduced cerebrovascular reactivity to acetazolamide on preoperative brain perfusion SPECT and MES during carotid exposure, 14 (44%) showed cerebral hyperperfusion (defined as postoperative CBF increase ≥100% compared with preoperative values), and 16 (50%) developed DWI-characterized postoperative cerebral ischemic lesions. Postoperative cerebral hyperperfusion was significantly associated with the absence of DWI-characterized postoperative cerebral ischemic lesions (95% confidence interval, 0.001–0.179; p = 0.0009). These data suggest that cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during carotid exposure in CEA, supporting the “impaired clearance of emboli” concept. Blood pressure elevation following carotid declamping would be effective when embolism not accompanied by cerebral hyperperfusion occurs during CEA.

Sensitivity and Specificity of Dual-Isotope 99mTc-Tetrofosmin and 123I Sodium Iodide Single Photon Emission Computed Tomography (SPECT) in Hyperparathyroidism.

PurposeDespite recommendations for 99mTc-tetrofosmin dual tracer imaging for hyperparathyroidism in current guidelines, no report was published on dual-isotope 99mTc-tetrofosmin and 123I sodium iodide single-photon-emission-computed-tomography (SPECT). We evaluated diagnostic accuracy and the impact of preoperative SPECT on the surgical procedures and disease outcomes.MethodsAnalysis of 70 consecutive patients with primary hyperparathyroidism and 20 consecutive patients with tertiary hyperparathyroidism. Imaging findings were correlated with surgical results. Concomitant thyroid disease, pre- and postoperative laboratory measurements, histopathological results, type and duration of surgery were assessed.ResultsIn primary hyperparathyroidism, SPECT had a sensitivity of 80% and a positive predictive value of 93% in patient-based analysis. Specificity was 99% in lesion-based analysis. Patients with positive SPECT elicit higher levels of parathyroid hormone and higher weight of resected parathyroids than SPECT-negative patients. Duration of parathyroid surgery was on average, approximately 40 minutes shorter in SPECT-positive than in SPECT-negative patients (89±46 vs. 129±41 minutes, p=0.006); 86% of SPECT-positive and 50% of SPECT-negative patients had minimal invasive surgery (p = 0.021). SPECT had lower sensitivity (60%) in patients with tertiary hyperparathyroidism; however, 90% of these patients had multiple lesions and all of these patients had bilateral lesions.ConclusionDual-isotope SPECT with 99mTc-tetrofosmin and 123I sodium iodide has a high diagnostic value in patients with primary hyperparathyroidism and allows for saving of operation time. Higher levels of parathyroid hormone and higher glandular weight facilitated detection of parathyroid lesion. Diagnostic accuracy of preoperative imaging was lower in patients with tertiary hyperparathyroidism.

Prediction of hyperperfusion after carotid artery stenting based on preoperative estimation of the cerebral blood flow (according to the Kuroda grading system) by single photon emission computed tomography

This study was conducted to investigate whether preoperative estimation of the cerebral blood flow (CBF) by single photon emission computed tomography (SPECT) can allow identification of patients at risk for hyperperfusion (HP) after carotid artery stenting (CAS). In 40 patients scheduled to undergo CAS, the CBF and cerebral vascular reserve (CVR) were measured prior to the intervention by resting and acetazolamide loading SPECT. The SPECT findings were classified into 4 types: Type 1, normal CBF in the resting state (CBFrest) and normal CVR; Type 2, normal CBFrest and reduced CVR; Type 3, reduced CBFrest and reduced CVR; and Type 4, reduced CBFrest and normal CVR. Four patients presented with HP after CAS. Patients with high proportions of Type 2 and Type 3 had high risk of HP after CAS. (ROC analysis: AUC=0.94, cutoff value of 75.8% had PPV of 75.0%, NPV of 97.2% and odds ratio of 105.0). The proportions of Type 2 and Type 3 in preoperative SPECT may identify patients at risk for the development of HP.

Post-Stress Perfusion Abnormalities Detected on Myocardial Perfusion Single-Photon Emission Computed Tomography Predict Long-Term Mortality After Elective Abdominal Aortic Aneurysm Repair

After abdominal aortic aneurysm (AAA) repair, relatively low survival during long-term follow-up remains an unresolved issue. Stress myocardial perfusion single-photon emission computed tomography (SPECT) well predicts future mortality overall, as well as providing diagnoses of coronary artery disease. The prognostic value of myocardial SPECT findings after AAA repair, however, remains unclear. This study followed 285 patients, all undergoing preoperative pharmacologic stress myocardial perfusion SPECT to determine summed stress score (SSS), then elective AAA repair by open AAA repair or endovascular aneurysm repair. The endpoint of the study was cardiac death. The median follow-up duration was 925 days (range, 541-1,095 days). Twenty-four (8%) died during follow-up. Kaplan-Meier analysis showed that patients with SSS≥9 had a significantly poorer prognosis than those with SSS<9 (76% vs. 93%, P=0.003). Multivariate Cox proportional hazards analysis indicated that SSS≥9, diabetes, and chronic kidney disease≥stage 3 could significantly and independently predict long-term cardiovascular mortality in patients after AAA repair (hazard ratio [HR], 4.2; 95% confidence interval [CI]: 1.8-9.7, P=0.001; HR, 3.0; 95% CI: 1.2-7.4, P=0.020; and HR, 4.1; 95% CI: 1.7-10.1, P=0.029, respectively). Preoperative pharmacologic stress myocardial perfusion SPECT is a useful method to predict long-term cardiovascular mortality for patients undergoing elective AAA repair.

Clinical Appraisal of 99mTechnetium-Sestamibi SPECT/CT Compared to Conventional SPECT in Patients with Primary Hyperparathyroidism and Concomitant Nodular Goiter

Although 99m Technetium-sestamibi scintigraphy with single-photon emission computed tomography (SPECT) and, recently, hybrid SPECT/computed tomography (CT) have been claimed to be the preoperative methods of choice for parathyroid localization in patients with primary hyperparathyroidism (PHPT) and concomitant nodular goiter (NG), they have never been compared in this setting. We aimed at testing the hypothesis that SPECT/CT may be superior to SPECT for parathyroid localization in patients with PHPT and NG. Thirty-three patients with PHPT and NG (one or more nodular lesions based on cervical ultrasound) who underwent open parathyroidectomy during 2004-2009 were reviewed. All patients had preoperative 99m Tc-sestamibi planar scintigraphy and SPECT (18 patients) or SPECT/CT (15 patients) after cervical ultrasound. Sensitivity, specificity, and positive predictive value (PPV) (for both correct neck side and quadrant identification) were calculated for the two procedures through comparison with intraoperative findings. In addition, operative times were assessed if the surgery was only for PHPT and not for the six patients who also had thyroidectomy. The sensitivity of SPECT/CT for correctly identifying the neck side containing an abnormal parathyroid was 93.7% versus 80% for SPECT (p = 0.21, not significant [ns]). The specificity and PPV for this attribute were 92.9% and 93.7%, respectively, for SPECT/CT versus 87.5% and 88.9%, respectively, for SPECT (p = 0.75 and 0.8, ns). SPECT/CT showed higher sensitivity than SPECT (87.5% vs. 55.6%; p = 0.0001) and higher PPV (87.5% vs. 62.5%; p = 0.0022) for correctly identifying the neck quadrant affected by PHPT. The specificity for this was 95.5% for SPECT/CT versus 88.5% for SPECT (p = 0.26, ns). Mean operative time was shorter after SPECT/CT than after SPECT (38 vs. 56 minutes; p = 0.034). One of the patients having SPECT/CT had double adenomas, and two had ectopic parathyroid glands, all of which were recognized preoperatively by this technique. Two of the patients having SPECT had double adenomas, and two had ectopic glands, none of which were recognized preoperatively. No patient had persistent or recurrent PHPT. SPECT/CT is superior to SPECT for preoperative imaging of patients with PHPT and NG. We recommend the routine use of SPECT/CT for work-up of all such patients, particularly if minimally invasive parathyroid surgery is planned.

Gated myocardial perfusion SPECT for preoperative risk stratification in patients with noncardiac vascular disease

Myocardial perfusion single photon emission computed tomography (SPECT) is useful for preoperative cardiac risk stratification. We investigated the value of preoperative pharmacologic stress electrocardiographic (ECG)-gated myocardial perfusion SPECT for noncardiac vascular surgery. To assess the perioperative cardiac risk for noncardiac vascular surgery, preoperative pharmacologic stress ECG-gated myocardial perfusion SPECT was performed in 211 consecutive patients who underwent noncardiac aortic surgery. We examined myocardial perfusion and left ventricular function by the quantitative gated SPECT (QGS), and the correlation with perioperative cardiac events was investigated. Perioperative cardiac events occurred in 9 of 211 patients (4.3%). On the basis of univariate analysis, significant predictors for preoperative cardiac risk stratification included history of heart failure (P < 0.05), history of coronary artery revascularization (P < 0.05), summed stress score (SSS) (P < 0.0001), summed rest score (SRS) (P < 0.005), SSS > or = 7 (P < 0.005), end-diastolic volume (EDV) > or = mean + 2 standard deviation (SD) (134 ml for men and 93 ml for women) (P < 0.005), end-systolic volume (ESV) > or = mean + 2 SD (60 ml for men and 37 ml for women) (p < 0.0001), left ventricular ejection fraction (EF) < or = mean - 2 SD (48% for men and 55% for women) (P < 0.005) and wall motion abnormality (P < 0.05). On the basis of multivariate analysis, ESV > or = mean + 2 SD was the only independent predictor for perioperative cardiac events (P < 0.005). Pharmacologic stress ECG-gated myocardial perfusion SPECT, which permits assessment of both myocardial perfusion and cardiac function, is useful for preoperative risk stratification of noncardiac vascular surgery.

Preoperative Risk Stratification With Myocardial Perfusion Imaging in Intermediate and Low-Risk Non-Cardiac Surgery

Perioperative cardiac risk in high risk surgery is often stratified with myocardial perfusion single-photon emission computed tomography (SPECT). However, little and no data are available about intermediate and low-risk surgery, respectively. A total of 1,220 consecutive patients underwent electrocardiography-gated dipyridamole stress SPECT to evaluate myocardial perfusion and cardiac function before intermediate or low risk non-cardiac surgery. Variables predictive of perioperative cardiac events were determined and the usefulness of combining pretest information and the incremental prognostic value of SPECT was estimated. The frequency of all cardiac events depended on clinical risk factors and type of surgical procedures. After sorting the patients with clinical risk factors and surgical risk, assessment of myocardial perfusion or cardiac function yielded significant risk stratification in intermediate, but not in low-risk surgery. Adding functional data to perfusion variables offered an incremental prognostic value for patients with an intermediate clinical risk and scheduled intermediate risk surgery. Integrating information about clinical risk factors, type of surgery, myocardial perfusion and cardiac function allows detailed preoperative risk stratification. Preoperative SPECT provides an incremental prognostic value in intermediate, but not in low-risk surgery.

Correlation of preoperative thallium SPECT with histological grading and overall survival in adult gliomas

The management and prognosis of a glioma depend on the tumour's histological grade. Thus, preoperative prediction of the grade is routinely needed to indicate whether surgery or biopsies are required. It has been proposed that thallium single photon emission computed tomography (SPECT), in a relative short series, will aid this prediction. To confirm the correlation between the results of preoperative thallium SPECT and grade of tumour as well as patient survival, and to define the cut-off value of the optimal thallium index for the detection of high grade gliomas in a large series of patients. One hundred and eighteen patients treated for glioma were retrospectively included in this study. All patients underwent preoperative 201Tl SPECT upon initial presentation and were referred for neurosurgery. Initial scintigraphic findings were correlated with the histological grade of the tumour and overall patient survival. Thallium uptake was highly correlated with histological grade; the mean thallium indices for low grade and high grade gliomas were 1.8 and 4.9, respectively. On the basis of receiver operating characteristic analysis, the optimal cut-off value of the thallium index for the detection of high grade glioma was determined. By using 2.2 as the value for the threshold thallium index, the sensitivity and specificity were 93% and 72%, respectively. Kaplan-Meier estimates of the overall survival curves, as a function of the thallium index, indicated that it was correlated with the overall survival (P<0.001). Thallium SPECT provides useful information about the histological grade of the tumour and overall patient survival. Additionally, in spite of its relatively weak resolution, it appears to be a powerful routine clinical tool for the management of gliomas.

Usefulness of technetium-99m methoxyisobutylisonitrile single-photon emission computed tomography and computed tomography in the evaluation of cervical lymph node metastasis

The aim of this study was to compare the effectiveness of technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) single-photon emission computed tomography (SPECT) and computed tomography (CT) in evaluating cervical lymph node metastasis of head and neck cancer. Histopathologic results of 166 cervical lymph node levels in 31 neck-dissected patients were compared with pre-operative CT and (99m)Tc-MIBI SPECT findings about cervical lymph node metastasis, retrospectively. Sensitivity, specificity and predictability of CT and (99m)Tc-MIBI SPECT were 68.2, 93.1 and 89.8 per cent and 59.1, 87.5 and 83.7 per cent, respectively. When analysing CT and(99m)Tc-MIBI SPECT together, sensitivity and specificity were 86.4 and 99.3 per cent, respectively. The combined use of (99m)Tc-MIBI SPECT and CT could increase the accuracy of cervical lymph node metastases detection, compared with separate use of either (99m)Tc-MIBI SPECT or CT.