Relationship between tumor volume and quantitative values calculated using two-dimensional bone scan images

Abstract

The bone scan index (BSI) is calculated from a whole-body bone scan image; it shows the tumor burden in bone as a percentage of total skeletal mass. It has been used to determine the prognosis and to assess treatment effects; however, little has been reported on whether the BSI calculated using a two-dimensional image can accurately evaluate the three-dimensional spread in tumor volume. We investigated the relationship between tumor volume and BSI using Monte Carlo simulation (MCS). We simulated a gamma camera and constructed a voxel phantom based on an anthropomorphic phantom computed tomography (CT) image and gamma rays emitted from each part according to technetium-99m-labeled methylene diphosphonate (Tc-MDP) uptake (bone 1, soft tissue 0.2, tumor 2-32). We constructed bone scan images from the obtained counts and analyzed them using the BSI calculation software. The BSI increased with increased tumor uptake (two- to 32-fold). However, there was not always a significant difference between change in BSI and tumor uptake of eight times or greater than that of bone. When BSI was calculated with a tumor having an uptake of four-to-eight times higher than that of bone, the BSI was consistent with tumor volume, but decreased to about half the tumor volume when tumors were in the thoracic spine (Th-spine) segment. The BSI can be a good indicator of tumor volume in most segments, even though it is affected by the tumor's Tc-MDP uptake. Nevertheless, values calculated from the Th-spine should be interpreted carefully.

Evaluation of bone metastatic burden by bone SPECT/CT in metastatic prostate cancer patients: defining threshold value for total bone uptake and assessment in radium-223 treated patients

“…We have investigated that BONENAVI ® often resulted in false-positive or false-negative in patients with small tumor burden (e.g., EOD = 1 and low activity) [ 24 ]. Others have also reported that BSI was strongly influenced by tumor location, volume, and scan uptake time in a simulation study [ 25 ] and clinical setting [ 26 ]. It could be due to attenuation by scatters and different activity of osteoblasts.…”

Automated classification of increased uptake regions in bone single-photon emission computed tomography/computed tomography images using three-dimensional deep convolutional neural network

“…When conducting research at multiple facilities, it is necessary to pay attention to changes in the quality of the input image. For example, the quality of CT images directly contributes to the accuracy of diagnostic ability as a fused image with SPECT as well as the evaluation of CT alone [9][10][11]20]. Although the CT image of our protocol had a low dose, we were able to evaluate the lesion by ensuring sufficient image quality in the diagnosis of bone lesions.…”

“…However, there are some challenges in whole-body planar analysis. For instance, information in the front-back direction is compressed 2D information, which renders the evaluation with the accumulation pattern insufficient (light accumulation) [8], with low accuracy of the area affected by overlap [9]. Recent years have witnessed an upsurge in the number of facilities that have added single-photon emission computed tomography/computed tomography (SPECT/CT), three-dimensional (3D) imaging, to whole-body planar scintigraphy.…”

Targeted parallel DNA sequencing detects circulating tumor‐associated variants of the mitochondrial and nuclear genomes in patients with neuroblastoma

“…The volume of bone marrow metastases was calculated incorporating related approaches form other imaging methods. 40 , 41 , 42 First, a reference was created for the total volume of bone marrow present in children in general using magnetic resonance data of three representative patients of different age (3 months, 1 year, 4 years). Then, patients' MIBG scintigraphy scans were evaluated for their MIBG‐distribution in bone marrow, and the distribution was set in correlation to the established reference to calculate the metastatic volume affecting the total bone marrow.…”

“…The volume of bone marrow metastases was added. The volume of bone marrow metastases was calculated incorporating related approaches form other imaging methods 40–42 . First, a reference was created for the total volume of bone marrow present in children in general using magnetic resonance data of three representative patients of different age (3 months, 1 year, 4 years).…”