Correlation of plain radiography and radionuclide scan findings in breast cancer patients with suspected bone metastasis in Kenyatta National Hospital and Agakhan University Hospital

Abstract

Introduction The presence of bone metastasis in patients with breast cancer impacts on the management options. The diagnosis of metastatic bone disease is important in staging, managing, followup and predicting prognosis in these patients. Whole body bone scans (WBBS) has long been considered the gold standard for imaging the bones in breast cancer patients presenting with bone pain, in order to exclude metastatic bone disease as the causative factor. It however provides a diagnostic dilemma when equivocal findings are noted. This study aims to correlate the findings of WBBS and Plain Radiography (PR) in the detection of Metastatic Bone Disease (MBD) .It also aims to rule out MBD from other types of bone pain like degenerative changes, referred pain, and soft tissue pain in order to obviate the need for aggressive imaging and reduce the radiation burden to patients. Methods The findings of 125 patients with breast cancer who were suspected to have metastatic bone disease were compared. Recruited patients complained of pain that was periodically resolving with analgesics. Patients with acute onset of sharp pain, referred pain, radicular pain and swelling around bone were required to undergo radiological investigations. All these patients were suspected to have MBD and as such were investigated further to exclude the same. . This was a seven-month prospective descriptive study from June 2013 to December 2013 undertaken at the Kenyatta National Hospital (K.N.H) Nuclear Medicine Unit, AgaKhan University Hospital Radiology Department and University of Nairobi Radiology Unit. Conclusions In most patients there was no evidence of bone metastasis on PR or WBBS. WBBS had higher sensitivity in detection of metastatic bone disease than PR. When used as an adjunctive diagnostic tool, PR assists in detecting the presence or absence of metastatic lesions with high level of confidence. The study emphasizes the role of PR and WBBS as baseline investigations in suspected bone metastasis in breast cancer patients. Overall there was significant difference in the detection rate of bone metastasis between the two modalities. Normal PR findings do not exclude bone metastasis but helps in diagnosis of degenerative disease which is not accurately detected by WBBS.