Retrospective accuracy analysis of MRI based lesion size measurement in neuroblastic tumors: which sequence should we choose?

Abstract

Background MR imaging of neuroblastic tumors is widely used for assessing the effect of chemotherapy on tumor size. However, there are some concerns that MRI might falsely estimate lesion diameters due to calcification and fibrosis. Therefore, the aim of our study was to compare neuroblastic tumor size based on MRI measurements to histopathology measurements of the resected specimens as standard of reference. Methods Inclusion criteria were diagnosis of a neuroblastic tumor, MR imaging within 100 days to surgery and gross total resection without fragmentation of the tumor between 2008 and 2019. Lesion diameters were measured by two radiologists according to RECIST 1.1 in axial plane in T2w turbo spin echo (TSE), diffusion-weighted imaging (DWI), and in T1w pre- and postcontrast sequences. Furthermore, the largest lesion size in three-dimensions was noted. The largest diameter of histopathology measurements of each specimen was used for comparison with MRI. Results Thirty-seven patients (mean age: 5 ± 4 years) with 38 lesions (neuroblastoma: n = 17; ganglioneuroblastoma: n = 11; ganglioneuroma: n = 10) were included in this retrospective study. There was excellent intra-class correlation coefficient between both readers for all sequences (> 0.9) Tumor dimensions of reader 1 based on axial MRI measurements were significantly smaller with the following median differences (cm): T1w precontrast − 1.4 (interquartile range (IQR): 1.8), T1w postcontrast − 1.0 (IQR: 1.9), T2w TSE: -1.0 (IQR: 1.6), and DWI -1.3 (IQR: 2.2) (p < 0.001 for all sequences). However, the evaluation revealed no significant differences between the three-dimensional measurements and histopathology measurements of the resected specimens regardless of the applied MRI sequence. Conclusions Axial MRI based lesion size measurements are significantly smaller than histopathological measurements. However, there was no significant difference between three-dimensional measurements and histopathology measurements of the resected specimens. T2w TSE and T1w postcontrast images provided the lowest deviation and might consequently be preferred for measurements.

Prognostic value of texture analysis of the primary tumour in high‐risk neuroblastoma: An 18F‐DOPA PET study

“…Although, morphological imaging, such as X-ray computed tomography (CT) or magnetic resonance imaging (MRI), is pivotal in identifying the risk profile of the primary tumour (i.e., image defined risk factors), it can be suboptimal in the accurate identification of bone and bone marrow involvement. [14][15][16] For this reason, staging of HR-NBL is carried out using scintigraphic imaging, and in particular 123 I-metaiodobenzylguanidine ( 123 I-MIBG) planar or tomographic scanning. [17][18][19] This method is highly sensitive in defining metastatic status, granting a whole-body approach in the treatment response assessment.…”

“…Given the complexity of the therapeutic approach, accurate staging and re‐staging tools are required. Although, morphological imaging, such as X‐ray computed tomography (CT) or magnetic resonance imaging (MRI), is pivotal in identifying the risk profile of the primary tumour (i.e., image defined risk factors), it can be suboptimal in the accurate identification of bone and bone marrow involvement 14–16 . For this reason, staging of HR‐NBL is carried out using scintigraphic imaging, and in particular 123 I‐metaiodobenzylguanidine ( 123 I‐MIBG) planar or tomographic scanning 17–19 .…”

Local MRI before and after Tumor Resection in Neuroblastoma: Impact of Residual Disease on Event Free Survival

“…In blurred images or images hampered by artifacts, T1 weighted post-contrast sequences were used instead. The same imaging sequence was used for preoperative as well as postoperative volumetry [25]. The reference standard was determined by evaluating the surgical report, available follow-up examinations and data, including available MIBG scans, and a final review by a senior pediatric radiologist and a senior pediatric surgeon.…”

1.5 vs 3 Tesla Magnetic Resonance Imaging

“…With 3 T DWI, image distortion and artifacts (eg, ghosting artifacts) are commonly seen, limiting the clinical benefit that is especially important for assessing osseous structures and tumor characteristics. [78][79][80][81] Another advantage of 1.5 T affects lung imaging in particular, mainly due to longer T2* of lung tissue. 82 Aside from lung imaging within this is especially relevant for diseases such as cystic fibrosis.…”

“…Apart from some implants that are only suitable for 1.5 T imaging (although implant issues are rarely relevant in pediatric MRI), the advantages of lower field strengths are noteworthy in DWI. With 3 T DWI, image distortion and artifacts (eg, ghosting artifacts) are commonly seen, limiting the clinical benefit that is especially important for assessing osseous structures and tumor characteristics 78–81 . Another advantage of 1.5 T affects lung imaging in particular, mainly due to longer T2* of lung tissue 82 .…”