ESTRO 2024 - Abstract Book

S2098

Clinical - Sarcoma, skin cancer, melanoma

ESTRO 2024

has been found to provide good results [3]. The introduction of these techniques for chordoma patients provides impetus to assess if there have been systematic shifts in patterns of care.

Material/Methods:

We performed a retrospective audit of all chordoma cases presenting to an Australian quaternary referral cancer centre from 1999-2023. The different types of treatment received and their impact on disease control rates were evaluated. Patients were identified through a prospectively curated clinical database, supplemented by manual review of the clinical notes and radiotherapy treatment plans. Descriptive statistics were gathered in R.

Results:

A total of 43 patients were treated in this time period, with 9 clival, 6 spinal and 28 sacral chordomas. An annotated swimmer’s plot (Figure 1) summarises the treatment trajectories for all patients. Radiotherapy was the most frequently utilised treatment modality with 38/43 (88%) patients treated, and was the first treatment for 15 patients. Surgery was the initial treatment modality for 26 patients, with 2 others having surgery shortly after neoadjuvant radiotherapy, for a total of 28/43 (65%) patients. Median time from diagnosis to final follow-up was 7.7 years by the reverse Kaplan-Meier method with a median survival of 11.8 years and median recurrence free survival of 4.4 years. Patients with spinal chordoma had worse recurrence free and overall survival (1.5 and 6.7 years respectively) than patients with clival (7.8 and 11.8 years) or sacral (5.3 and 14.2 years) primaries (p < 0.05). Patients with clival and spinal chordomas almost invariably had upfront surgery. The majority of patients with sacral chordoma received radiotherapy (24/28, 86%), with patients diagnosed after 2010 more likely to receive upfront radiotherapy (14/21 vs 1/7), of whom 3 received SABR. The patients receiving radiotherapy as their first treatment modality had a longer time to first recurrence (7.5 years) than those who had upfront surgery (4.5 years). This was not statistically significant and is likely attributable to the shorter follow up period in the radiotherapy group and the absence of clear criteria to delineate disease progression after radiotherapy.