The Economic Value of Hybrid Single‐photon Emission Computed Tomography With Computed Tomography Imaging in Pulmonary Embolism Diagnosis

Abstract

ObjectiveThe objective was to quantify the potential economic value of single‐photon emission computed tomography (SPECT) with computed tomography (CT; SPECT/CT) versus CT pulmonary angiography (CTPA), ventilation–perfusion (V/Q) planar scintigraphy, and V/Q SPECT imaging modalities for diagnosing suspected pulmonary embolism (PE) patients in an emergency setting.MethodsAn Excel‐based simulation model was developed to compare SPECT/CT versus the alternate scanning technologies from a payer's perspective. Clinical endpoints (diagnosis, treatment, complications, and mortality) and their corresponding cost data (2016 USD) were obtained by performing a best evidence review of the published literature. Studies were pooled and parameters were weighted by sample size. Outcomes measured included differences in 1) excess costs, 2) total costs, and 3) lives lost per annum between SPECT/CT and the other imaging modalities. One‐way (±25%) sensitivity and three scenario analyses were performed to gauge the robustness of the results.ResultsFor every 1,000 suspected PE patients undergoing imaging, expected annual economic burden by modality was found to be 3.2 million (SPECT/CT), 3.8 million (CTPA), 5.8 million (planar), and 3.6 million (SPECT) USD, with a switch to SPECT/CT technology yielding per‐patient‐per‐month cost savings of $51.80 (vs. CTPA), $213.80 (vs. planar), and $36.30 (vs. SPECT), respectively. The model calculated that the incremental number of lives saved with SPECT/CT was six (vs. CTPA) and three (vs. planar). Utilizing SPECT/CT as the initial imaging modality for workup of acute PE was also expected to save $994,777 (vs. CTPA), $2,852,014 (vs. planar), and $435,038 (vs. SPECT) in “potentially avoidable”’ excess costs per annum for a payer or health plan.ConclusionCompared to the currently available scanning technologies for diagnosing suspected PE, SPECT/CT appears to confer superior economic value, primarily via improved sensitivity and specificity and low nondiagnostic rates. In turn, the improved diagnostic accuracy accords this modality the lowest ratio of expenses attributable to potentially avoidable complications, misdiagnosis, and underdiagnosis.

Ventilation perfusion single photon emission computed tomography: Referral practices and diagnosis of acute pulmonary embolism in the quaternary clinical setting

“…A French study (584 patients, 2005) stated inconclusive findings in 3% of V/Q SPECT reports . A recent meta‐analysis performed in the United States determined the weighted average of equivocal V/Q SPECT to be 5.8% . However, the standard technique for V/Q SPECT in the US involves the use of Xenon radiotracer rather than Technegas rendering direct comparison of equivocal rates less useful.…”

“…V/Q SPECT is also used as a second line investigation when a CTPA study is non‐diagnostic or has equivocal findings. Recently, a few systematic reviews and meta‐analyses have been published which concluded that V/Q SPECT was superior or equal to CTPA in most clinical settings with better overall diagnostic performance …”

“…It is suspected that the historically high rates of equivocal findings in VQ planar studies, 1 have resulted in physicians continuing to preference CTPA as the first line imaging for suspected PE. More recent research indicates the rates of equivocal or indeterminate V/Q SPECT studies varies widely, between 0% and 17%, 2 and typically, indeterminate rates are less than 5%. [3][4][5] For young women, pregnant patients, those with impaired renal function and previous contrast reactions, V/Q SPECT is the modality of choice to define or exclude acute pulmonary emboli.…”

“…Recently, a few systematic reviews and meta-analyses have been published which concluded that V/Q SPECT was superior or equal to CTPA in most clinical settings with better overall diagnostic performance. 2,7 It is proposed that V/Q SPECT can provide a definitive report in greater than 98% of investigations of acute PE, dispelling the myth of high rates of indeterminate findings. It is hoped that a low rate of inconclusive findings will encourage physicians to consider V/Q SPECT as the first line investigation of suspected acute PE in pregnant patients and females under the age of 55.…”

Cost-Effectiveness of Bone SPECT/CT in Painful Total Knee Arthroplasty

“…Descriptive data from single-modality series were used if direct comparison data were unavailable. Sample size weighted estimates were synthesized in the case of multiple data sources to mitigate outlier bias (45).…”