A correlation analysis of sacrococcygeal chordoma imaging and clinical characteristics with the prognostic factors

Abstract

Objective: To investigate the imaging and clinical risk factors related to the postoperative recurrence of sacrococcygeal chordoma.

Methods: 63 patients of sacrococcygeal chordoma proved by operation and pathology in our hospital from January 2009 to December 2019 were retrospectively analyzed in the related factors of imaging manifestations, pathological type, and extent of surgical resection. The recurrence of sacrococcygeal chordoma was followed up. Univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to analyze the related factors of recurrence.

Results: On plain radiographs and CT scans, chordoma primarily manifested as osteolytic bone loss and uneven soft tissue mass, with typical calcification or ossification (56.1 percent). Numerous chunk nodules with clearly high signal levels and short signal intervals were seen as the "pebble" in MRI characteristics on T2WI. The follow-up period ranged from 20 to 130 months, with a median time of 47.5 months. There were 14 recurrences (22. 2%) during the follow-up period. 13 patients with recurrence underwent surgery again, and 5 of them recurred after surgery (recurrence time range 3 to 97 months, median 38. 5 months). 6 (42.8%), 8 (57. 1%), and 13 (92. 9%) of the 14 patients with recurrence recurred within 2, 3, and 5 years after surgery, respectively. Univariate Kaplan-Meier survival analysis showed that occurred with local infiltration, Low differentiated chordoma, partial resection had a high postoperative recurrence rate, and all differences were statistically significant (P<0.05). Multi-factor Cox regression analysis showed whether local infiltration occurred and the degree of tumor resection were independent risk factors for tumor recurrence.

Conclusion: Sacrococcygeal chordoma has a high tendency of recurrence, and the likelihood of recurrence is higher in tumor occurred with local infiltration, non-complete tumor resection and low differentiated chordoma, which can be considered to shorten the review cycle and complete tumor resection as much as possible during surgery.

Keywords: Chordoma; imaging; prognosis; recurrent; survival analysis.

Figure 1

Male, 64 years old, with a former sacrococcygeal chordoma that recurred 8 times over 9 years. The recurrent tumor increased significantly in extent with the number of recurrences. Figure 1A Axial CT shows osteolytic destruction of the right side of the pubic symphysis with a soft tissue mass. Figure 1B MR axial and Figure 1C sagittal T₂ WI pelvic area and bilateral medial thigh masses showed “pebble-like” clusters of apparently high-signal mass nodules with low-signal intervals. Figure 1D Coronal CT enhancement scan shows significant inhomogeneous enhancement. Figure 1E CT shows multiple small metastatic nodules in both lungs. The pathology of Figure 1F shows a few small round cells scattered in a background of mucus-like stroma, and combined with the immunohistochemical results (S-100 protein positive, GFAP positive, D2-40 positive, EMA negative), the diagnosis of chordoma was made.

Figure 2

Overall recurrence-free survival curve for sacrococcygeal chordoma.

Figure 3

Recurrence free survival curve for sacrococcygeal chordoma with or without local infiltration .

Figure 4

Recurrence free survival curve for different surgical resection ranges of sacrococcygeal chordoma.