SPECT/CT and PET/CT for the Evaluation of Persistent or Recurrent Pain After Spine Surgery: A Systematic Review and Case Series

OBJECTIVE

The differential diagnosis for postoperative back pain is broad, and conventional imaging modalities are not always conclusive. Therefore, we performed a systematic review of the literature and present case studies describing the use of single-photon emission CT (SPECT)/CT or positron emission tomography (PET)/CT in the diagnosis of back pain following spine surgery.

METHODS

A systematic review was conducted according to PRISMA guidelines across 5 databases. Relevant keywords included PET/CT, bone SPECT/CT, and pseudarthrosis. The studies were assessed for diagnostic accuracy of the imaging technologies.

RESULTS

A total of 2,444 studies were screened, 91 were selected for full-text review, and 21 were ultimately included. Six retrospective studies investigated the use of SPECT/CT with a total sample size of 309 patients. Two of these studies used SPECT/CT to predict screw loosening in over 50% of patients. Eight studies examined the use of 18-fluoride sodium fluoride (18F-NaF) PET/CT. Among these studies, measures of diagnostic accuracy varied but overall demonstrated the ability of 18F-NaF PET/CT to detect screw loosening and pseudarthrosis. Seven studies examined 18F-fluorodeoxyglucose (FDG) PET/CT and supported its utility in the diagnosis of postoperative infections in the spine.

CONCLUSIONS

PET/CT and SPECT/CT are useful in the evaluation of postoperative pain of the spine, especially in patients for whom conventional imaging modalities yield inconclusive results. More diagnostic accuracy studies with strong reference standards are needed to compare hybrid imaging to conventional imaging.

Do preoperative clinical and radiographic characteristics impact patient outcomes following one-level minimally invasive transforaminal lumbar interbody fusion based upon presenting symptoms?

BACKGROUND CONTEXT

Patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) frequently present with lower extremity neurologic symptoms with or without associated lower back pain. While symptomatic improvement of leg and back pain has been reported, the resolution of back pain when it is a predominant presenting symptom remains underreported following MI-TLIF.

PURPOSE

The purpose of this study was to compare clinical outcomes at 1 year of patients undergoing MI-TLIF with lower extremity neurologic symptoms with and without a significant component of back pain.

STUDY DESIGN

A retrospective review of prospectively collected data from a single surgeon surgical database from 2017 to 2019 was performed.

PATIENT SAMPLE

Fifty one patients undergoing MI-TLIF.

OUTCOME MEASURES

Self-reported measures included the Oswestry Disability Index (ODI), Visual analog scale back pain (VAS-back), and VAS leg pain (VAS-leg).

METHODS

Patients were divided into two groups: Leg Pain Predominant (patients reported greater than 50% leg pain upon presentation) and Back Pain Predominant (patients reported 50% or greater back pain). Multivariate analysis was performed to determine differences between groups based upon any significantly baseline characteristics.

RESULTS

Preoperative demographic and radiographic outcomes were similar between the two groups. Both groups demonstrated significant improvement in ODI, VAS-Back and VAS-leg at 1-year postoperatively. On multivariate analysis, there were differences in ODI at 1-year, 1-year back pain, and 1-year leg pain between groups with those who initially presented with leg pain having a lower ODI, VAS Back, and VAS leg. Patients who presented with predominantly leg pain were more likely to meet minimal clinically important difference (MCID) criteria for ODI and VAS-back compared to those with predominantly back pain.

CONCLUSION

Following MI-TLIF, patients with lower extremity neurologic symptoms with and without a significant component of back pain have improvements in back pain, leg pain, and ODI regardless of their primary presenting pain complaint; however, patients who presented with predominantly leg pain were more likely to meet MCID criteria for improvement in their back pain and ODI score.