Differential Diagnosis of Metastatic Bone Disease and Benign Bone Disease on Spine SPECT in Patients with Low Back Pain

요통 환자의 척추골 SPECT에서 골전이 병변과 양성골질환의 섭취 양상 분석을 통한 감별진단이 가능한가

Purpose: One or more abnormal vertebrae detected on bone scintigraphy is a common finding in clinical practice, and it could pose a diagnostic dilemma especially in cancer patients. as either metastasis or benign disease may cause scintigraphic abnormality. The purpose of this study was to determine whether additional spine SPECT has a role in differentiating malignant from benign lesions in patients with back pain. Materials and Methods: We reviewed spine SPECT studios obtained over a three-year period in 108 patients. Among them, forty-five patients with abnormal SPECT and clinically followed records were evaluated (20 cancer patients were included). Uptake patterns were classified as follows: 1. Body: diffusely increased uptake, linear increased uptake of end plate, segmental increased uptake, and cold defect, 2. Posterior element: posterior to body (pedicle), posterior to Intervertebral disc space (facet joint), and spinous process. Lesions were correlated with radiological findings and with final diagnosis. Results: Sixty-nine bone lesions were detected on SFECT images, including 18 metastases, 28 degenerative diseases and 21 compression fractures. Cold defect (6) and segmental increased uptake (5) were dominant findings in metastasis; linear increased uptake (12), and facet joint uptake (15) were in degenerative change; and diffuse increased uptake (9), and linear increased uptake (9) were in compression fracture. Conclusion: Cold defect and segmental increased uptake of body were characteristic findings of metastasis, but care should be taken because compression fracture also shows segmental increased uptake in some cases. Degenerative disease was easily diagnosed because of the typical finding of linear increased uptake of end plate and facet joint. Therefore, additional bone SPECT after planar bone scan would be helpful for differentiating metastasis from benign condition in cancer patients.

목적: 요통을 호소하는 암환자에서 골스캔을 시행하여 척추골의 섭취증가를 보이는 경우, 골전이와 양성 골질환의 구분이 모호한 경우가 많다. 이에 척추골 SPECT를 추가로 시행하는 것이 악성과 양성 골질환을 감별하는데 도움이 되는지 알아보고자 섭취양상을 분석하였다. 대상 및 방법: 3년간 척추골 SPECT를 시행한 108명의 환자중 SPECT에서 이상 섭취 병변을 보이고 임상적으로 추적이 가능하였던 45명의 환자의 67개의 병변의 척추골 SPECT소견을 다음과 같이 구분하고 임상소견 및 방사선학적 소견과 비교하였다. 1. 척추체: A. 전반적인 섭취증가, B. 추간판에 연한 선상의 섭취증가, C. 냉소의 동반, D. 분절상 섭취증가, 2. 척추후면체 A. 척추체 후면(lamina, pedicle 등), B. 추간판후면(후관절 등), C 극돌기 결과: 골전이 병변(18)은 척추체의 냉소동반(6), 분절상 섭취증가(5)가 특징적이었으며, 퇴행성변화(28)는 추체연의 선상 섭취증가(12), 추간판후면의 후면체 섭취증가(15), 압박골절(21)은 전반적인 척추체 섭취증가(9) 및 추체연의 섭취증가(9), 냉소동반(1), 분절상 섭취증가(1)와 극돌기의 섭취증가(3)을 보였다. 결론: 척추골 SPECT의 섭취증가 양상은 냉소동반, 분절상 섭취증가를 보이는 경우에 골전이 병변의 가능성이 크지만 압박골절에서도 같은 소견을 보일 수 있으므로 주의하여야 할 것이며, 퇴행성 질환은 특징적인 소견을 보이므로 감별이 가능하였다. 그러므로 골스캔 후 척추골 섭취 이상이 있는 암환자에서 추가 SPECT검사가 도움이 될 것으로 생각된다.