Accuracy and Precision of Bone Scan, Magnetic Resonance Imaging (MRI) and Digital Radiography in Limb Salvage Surgery for Long Bone Tumors

Abstract

Introduction: The aim of this study is to evaluate the level of accuracy and precision of bone scan (BS), magnetic resonance imaging (MRI) and digital radiography (DR) to measure long bone tumors to design custom made prosthesis (CMP)/modular prosthesis (MP) in limb salvage surgery (LSS). Material and methods: There are two separate groups, one is phantom study and another one is patient’s study. Phantom study: done with Jaszack phantom for gamma camera (GC) and indigenous phantom for MRI and DR. Three independent imaging professionals (nuclear medicine physicians and radiologists) measured the distance between standardized, preselected points on the Jaszack phantom in the GC and indigenous phantom on the coronal and sagittal view of the MRI scan and in DR. The measured values were compared it with the known values for phantom measurement. Patient’s study: Patients with a malignant bone tumor of the lower/upper limbs enrolled from 2020-2021 at the institute were taken up for the retrospective study. Totally 36 patients were enrolled, 24 patients were male (Ages: 2 to 45 years) and 12 patients were female (Ages: 8 to 18 years). Three independent imaging professionals measured the patient’s long bone in the BS, MRI and DR and compared with histopathological specimen measurement after LSS. Statistical analysis: Descriptive statistics using appropriate measures of central tendency, dispersion, Karl-Pearson correlation coefficient and paired t-test were employed. Results: A near perfect positive correlation was evident between all three pairs of the BS, MRI scan and DR values and a positive agreement within 1 mm was around 95%. Conclusion: For the phantom study, we conclude that GC and MRI measurements are equal in physical measurements and multiplication correction factor (MCF) = 1. DR measurements were found to be near equal physical measurements and MCF = 0.9104 and three observer’s measurements values were also near normal.