J Neurol Surg B Skull Base
DOI: 10.1055/a-2538-3865
Original Article

Intraosseous Pseudoprogression vs. Progression and Recurrence of Clival Chordoma after Proton Radiation Therapy: Case Series

1   Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA
,
Yuki Shinya
1   Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA
,
Anita Mahajan
2   Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
,
Nadia N. Laack
2   Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
,
Aditya Raghunathan
3   Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
,
Ian T. Mark
4   Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
,
1   Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA
› Institutsangaben
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Abstract

Objective To propose a novel entity of possible intraosseous pseudoprogression in clival chordoma following proton radiation therapy (PRT).

Methods A total of 38 consecutive patients who underwent surgical resection followed by PRT for clival chordoma between January 2015 and December 2023 were analyzed retrospectively. Follow-up magnetic resonance imaging (MRI) suggesting recurrence or progression was evaluated for validity. Apparent diffusion coefficient (ADC) and tumor-to-brainstem signal intensity ratio on contrast-enhanced T1-weighted imaging (Rce) were assessed. Pseudoprogression was defined as (1) MRI signs of recurrence or progression with no pathological confirmation despite obtaining a specimen, or (2) MRI signs of recurrence or regression with spontaneous resolution/regression.

Results Of the 11 patients with MRI findings suggestive of recurrence or progression, 3 were diagnosed with recurrence, 5 with progression, and 3 with pseudoprogression. Patients with pseudoprogression were significantly younger than those with progression (p = 0.04), and all were female. The median time to recurrence, progression, and pseudoprogression was 31, 29, and 21 months, respectively. The three pseudoprogression cases were managed with gross-total resection followed by stereotactic radiosurgery, extensive biopsy, and observation, respectively. Although statistical significance was not reached, ADC (p = 0.33) and Rce (p = 0.13) tended to be higher in pseudoprogression cases.

Conclusion After PRT for clival chordoma, intraosseous pseudoprogression should be considered in the differential diagnosis, particularly in relatively young female patients, although the role of ADC and Rce on MRI remains inconclusive. Multidisciplinary teams managing chordomas should take this into account when determining the aggressiveness of treatment in such cases.



Publikationsverlauf

Eingereicht: 15. November 2024

Angenommen: 12. Februar 2025

Accepted Manuscript online:
14. Februar 2025

Artikel online veröffentlicht:
03. März 2025

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