Background/Purpose: Currently, the techniques used for the monitoring of Localized Scleroderma of the face (LSF) have significant limitations. We prospectively evaluated the reliability of the Cone Beam Computed Tomography (CBCT), a non-invasive, reproducible technique with a radiation dose lower than a conventional CT, to quantify changes of facial asymmetry over time as compared with the clinical and instrumental methods currently in use.

Methods: Consecutive patients with LSF, followed from January 2009 to December 2017 at our Pediatric Rheumatology Center, entered the study. CBCT was carried out following the same method previously described¹. Measurements of total thickness, soft tissue and bone thickness were taken in both affected and unaffected sides of the case. These data allowed us to calculate the Absolute Rate of Change (ARC) of the lesion over time and the comparison with the ARC obtained from the healthy side, allowed us to calculate the Relative Rate of Change (RRC). The judgment of stability or worsening of the lesion was compared with the one derived from the physician global assessment (PGA), infrared teletermography (IT) and sequential clinical photographs (SCP). The Sensitivity-to-change of CBCT was assessed by Standardized Response Mean (SRM) and Effect Size (ES).

Results: 26 subjects with LSF, 15 females and 11 males, mean age 7.6 years (range 1.2-17.8) entered the study. 18 patients presented Parry Romberg syndrome (PRS), 5 En coup de sabre (ECDS) and 3 facial hemiatrophy (FH). The disease duration at the first CBCT was 3.7 years (range 0-28). During the study period, 69 CBCTs have been performed. On average, each patient underwent 2.7 CBCTs, 15 patients underwent two CBCTs, 8 patients three, and one patient 4, 5 or 6 CBCTs each, respectively. In all, the total thickness of the affected and unaffected side were evaluated. A worsening of CBCT with RRC > 5%, was found in 10 out of 40 evaluations (25%). The agreement between the CBCT and SCP was found in 20 out of 37 evaluations (54%). The comparison of the four clinical-instrumental methods performed in 40 evaluations, revealed an overall agreement of 66.7%. CBCT results were consistent with the PGA in 67.6% evaluations, with IT in 62.2%. The sensitivity to change of CBCT over time was very good at the mandibular condyle level (SRM values ranging from 0.53 to 0.77, ES 0.40-0.50) on the healthy side. The affected side reported SMR and ES values <0.5.

Conclusion: CBCT is an innovative technique that allows to assess the changes of the affected side, usually the non-growth, of LSF in comparison with the healthy side, during the developmental phase of pediatric patients. CBCT represents a reliable and objective tool for monitoring LSF over time in association with the other clinical-instrumental methods currently in use. Its practical benefit lies in its potential of correctly addressing therapeutic changes including the timing of start the reconstructive surgical process.

1.Di Giovanni C. et al. Cone beam computed tomography for the assessment of linear scleroderma of the face. Pediatric Rheumatology 2018; 16: 1.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/prospective-validation-of-cone-beam-computed-tomography-for-the-assessment-of-disease-progression-in-linear-scleroderma-of-the-face/