Purpose
Chordomas and chondrosarcomas are locally invasive relatively rare tumors at the skull base with reported similar radiological features but different origin (Figure 1), Chordomas arise from remnants of the primitive notochord, chondrosarcomas can arise from bone, cartilage and tissue without cartilaginous components and are at the skull base commonly found near the petro-occipital synchondrosis. Aim of this retrospective study was to characterize the radiological features of chordomas and chondrosarcomas of the skull base in a patient collective referred for proton radiation therapy and to determine...
Methods and Materials
Between January 2007 and June 2009, 71 patients (n=32 females, n=39 males, median age 48) with skull base tumors (n=50 chordomas, n=21 chondrosarcomas) underwent MRI in preparation of Proton Radiation Therapy at the Paul Scherrer Institute. Amongst these histopathology revealed two (10%) chondroid chordomas and three (6%) conventional higher graded (grade 2) chondrosarcomas. Figure1 (Table 1) summarizes some of the demographic characteristics of both patient groups. The mean age was similar in both groups of patients. A male predominance was found in the chordoma group....
Results
The MR imaging of chordomas (Figure 1) and chondrosarcomas (Figure 2) at the skull base is quite variable as far astumor volume, shape, MR signal homogeneity and contrast enhancement is concerned. In our study both tumor entities presented with a more or less lobulated shape. They usually showed T2w profound hyperintense signal intensities sometimes with hypointense septations (Figure 1) and T1w hypo- to isointense signal intensities to brain parenchyma. After contrast administration T1w no clear signal intensity pattern was observed within our groups of patients,...
Conclusion
Accurate differentiation of both tumor entities was not possible on the basis of pre- or postsurgical imaging. Best imaging criteria for differentiation of chordomas and chondrosarcomas at the skull base in our patient groups is still their site of origin despite topographic classification limitation due to the extent of tumour invasion at time of diagnosis. Our findings support the current opinion that skull base chordomas are mostly located at the midline (Figure 1), chondrosarcomas predominately in the vicinity of the petro-occipital synchondrosis (Figure 2).
References
Ares C, Hug EB, Lomax AJ,et al. Effectiveness and safety of spot scanning proton radiation therapy for chordomas and chondrosarcomas of the skull base: first long-term report. Int J Radiat Oncol Biol Phys.2009 Nov 15;75(4):1111-8. Erdem E, Angtuaco EC, Van Hemert R,et al.Comprehensive review of intracranial chordoma. Radiographics.2003 Jul-Aug;23(4):995-1009. Gay E, Sekhar LN, Rubinstein E,et al. Chordomas and chondrosarcomas of the cranial base: results and follow-up of 60 patients. Neurosurgery.1995 May;36(5):887-96; discussion 896-7. Oot RF, Melville GE, New PF, et al. The role of MR...
Personal Information
Müller U, Kubik-Huch RA, Löw R. Institute of Radiology, Kantonsspital Baden AG, Baden, Switzerland.mail to:
[email protected] C, Hug E. Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland.