Preoperative 3-dimensional (3D) reconstruction (3DR) helps surgeons identify vascular structures within tumors during surgery in pediatric patients, according to the results of a study published in Pediatric Blood & Cancer.
The investigators conducted a prospective, observational single-center study to assess the discrepancies of preoperative 3DR compared with 2-dimensional (2D) images and surgical findings in pediatric tumors, and to characterize the advantages associated with 3DR.
Patients included in the study had thoraco-abdominal tumors with predictable surgical risks on preoperative images assessed by computer tomography (CT) scan (or in 1 case magnetic resonance imaging). They were classified as vascular/nervous risks for resection of the whole tumor, such as encasement of vessels, and parenchyma preservation of the invaded organ.
The 2D images were assessed first by the surgeons operating on the patients followed by the 3DR. The surgeons then determined if the 3DR was in agreement with their original assessment of the relationship between vascular/nervous structures and the tumor/parenchyma. After surgery, discrepancies between the surgical, 2D, and 3DR findings were noted.
In total, 24 patients (median age, 68.2 months; range, 13 days-203 months) underwent surgery between 2016 and 2019. Tumor types included neuroblastoma (7 cases), renal tumor (7 cases), hepatic tumor (4 cases), bone sarcoma of the iliac branch (1 case), abdominal lymph nodes of a recurrent testicular germ cell tumor (1 case), pseudoinflammatory tumor of the omentum (1 case), thoracic lipoblastoma (1 case), desmoplastic tumor (1 case), and solid and pseudopapillary tumor of the pancreas (1 case).
Discrepancies were noted for 4 patients with renal tumors. For 2 of these patients, the CT had no excretory phase; thus, the surgeon could not adequately evaluate caliceal invasion by the tumor.
In the 2 other patients, discrepancies between the 3DR and surgical findings were noted. In one case, renal nodules were suspected of caliceal infiltration on 2D imaging but that was not modeled on 3DR; during surgery, the calyx had to be divided to perform a complete resection. In the other case, CT images showed a thrombus in the renal vein, but the 3DR showed the thrombus in the inferior vena cava. During surgery, the thrombus was found in the renal vein abutting the inferior vena cava.
For all other tumors, the 3DR was found to improve visualization and localization of vascular/nervous structures during surgery.
“The surgeons found it more convenient and time saving to review 3DR during surgery when required, rather than scrolling through 2D images,” wrote the authors.
Following the study, 2 patients died (a patient with ganglioneuroma during surgery due to blood loss and a patient with desmoplastic tumor owing to progression). The other patients remain free of disease.
3DR gave surgeons an actual 3D model for reference instead of having to rely on mental visualization of a 3D model based on the 2D frontal, sagittal, and axial CT images. The 3DR estimation of remnant organ volume was considered very helpful, especially for liver resection. Additionally, the authors believe 3DR may be a valuable tool to teach liver and vascular anatomy.
Limitations of the study included the small sample size and a lack of independent review of the images/3DR.
“High-quality CT scan and MRI are mandatory to provide the best 3DR, but should be balanced with radiation exposure in children,” wrote the authors. “3D preoperative images are of significant help during surgery to better identify vascular structures within tumors and to preserve parenchyma. Further prospective multicenter studies are needed to ascertain both the reliability and the usefulness of 3DR.”
Irtan S, Hervieux E, Boutroux H, et al. Preoperative 3D reconstruction images for paediatric tumours: Advantages and drawbacks. Pediatr Blood Cancer. Published online August 22, 2020. doi:10.1002/pbc.28670