Utility of hybrid SPECT-CT in the detection of unsuspected single lytic vertebral metastases in renal cell carcinoma.

Authors describe the incremental value of hybrid SPECT-CT in upstaging disease and changing the management strategy of a case of renal cell carcinoma.

INTRODUCTION

Bone scintigraphy is less sensitive for detection of osteolytic lesions. We describe the utility of hybrid modality SPECT-CT in demonstrating the osteolytic lesion on morphological (CT) component of SPECT-CT associated with focal subtle tracer uptake.[1‐3]

CASE REPORT

We report the case of a 47-year-old male patient who presented with abdominal pain, lower urinary symptoms and hematuria for three months. He was diagnosed as a case of renal cell carcinoma and subjected to radical nephrectomy. The patient also underwent a whole body bone scan for a metastatic workup. A planar whole body bone scan along with a hybrid single photon emission computed tomography (SPECT) / Computed Tomography (CT) imaging was performed. The planar imaging showed an area of mildly increased tracer uptake in the second lumbar vertebra [Figure 1]. Subsequent SPECT / CT imaging revealed a lytic lesion in the L2 vertebra, with increased uptake in the rest of the vertebral body; the findings more likely to be with metastatic involvement [Figure 2]. Thus, SPECT / CT upstaged the disease and changed the management strategy. In conclusion the present case report emphasizes the importance of a hybrid SPECT / CT imaging for suspicious bone lesions on planar images.

Figure 1

Planar bone scintigraphy performed after I.V. injection of technetium labeled MDP showing very mild increase in the L 2 vertebra prompted a hybrid SPECT-CT imaging of the lumbar spine. Post Left nephrectomy status is also noticed

Figure 2

Hybrid SPECT-CT images revealing cortical destruction of the L2 vertebra. The photopenic region in SPECT images corresponding to the site of destruction