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High-Dose Single-Fraction Radiotherapy for the Management of Chordomas of the Spine and Sacrum. Yoshiya Yamada M.D., Ilya Laufer M.D., Brett W. Cox M.D., Michael D. Lovelock M.D., Robert G. Maki M.D. Ph. D., Joan M. Zatcky N.P., Patrick J. Boland M. D., Mark H. Bilsky M.D.
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High-Dose Single-Fraction Radiotherapyfor the Management of Chordomasof the Spine and Sacrum Yoshiya Yamada M.D., Ilya Laufer M.D., Brett W. Cox M.D., Michael D. Lovelock M.D., Robert G. Maki M.D. Ph. D., Joan M. Zatcky N.P., Patrick J. Boland M. D., Mark H. Bilsky M.D. Memorial Sloan-Kettering Cancer Center
Chordoma treatment • Surgery – primary treatment • Goal - En bloc, Wide margin • Radiation • Inoperable/intralesional • Previous surgery • Recurrence • Chemotherapy • Salvage/palliation
Surgical Summary • Wide margin – 57% (35-75) • Recurrence-free survival – 45% (40-67) • 5y – 62% (52-66) • 10y – 46% (33-52) • Survival • Tumor-related death – 26% (21-47) • 5y – 74% (54-97) • 10y – 53% (21-71) York 1999, Fourney 2005, Bergh 2000, Fuchs 2005, Boriani 2006, Hanna 2008, Schwab 2009, Ruggieri 2010, Stacchiotto 2010
Radiation Summary • Photon Therapy • Resistant to conventional fractionation • Proton Therapy • 5y Recurrence – 10%1, 27%2, 32%3, • Carbon Therapy • 5y Recurrence – 12%4 • Factors • GTV, implants 1DeLaney 2009 2Wagner 2009 3Staab 2011 4Imai 2011
Necrosis After SRS • 2m post- SRS • 4m post- SRS • L3 chordoma after single-fraction 2400 cGy SRS showing ghost outlines of epitheliod cells and extensive necrosis
Single-Fraction Radiation • More irreparable damage to DNA • Endothelial apoptosis1 • Overcomes stem cell resistance2 1Garcia-Barros 2003 2Chang 2005
Hypothesis • Single-fraction SRS can be safely administered as a treatment of chordomas in the mobile spine and sacrum with good short-term local control
Methods • Study design: Retrospective review • Study population • Patients with chordomas of the mobile spine and sacrum treated between 2006 and 2010 • Inclusion criteria • Single-fraction SRS • Exclusion criteria • Follow-up less than 6 months
Methods • 62F presented with odynophagia secondary to a C3 chordoma
Methods • 73M presented with bowel incontinence and left foot numbness
Methods • 59F presented with back pain and high-grade spinal cord compression secondary to chordoma metastasis to T7
Methods • SRS • Inverse optimized treatment plan • Onboard orthogonal KV and cone beam imaging • Median prescribed dose – 2400 cGy (1800-2400 cGy) • Primary endpoint • Local tumor control • Secondary endpoint • Treatment-related toxicity (CTAE v.4)
Methods • Stratification variables • Histologic subtype • Location • Size • Dose • Follow-up • Clinical data and serial MRIs obtained every 3-4 months • Data sources • Chart and imaging review
Tumor Characteristics Tumor volume – 88cc (26-859cc) 2 Dedifferentiated Chordomas
Treatment Characteristics V100 – median 95% (72-100%)
Local Progression • 1 recurrence – 95% local control • 11 months after SRS, died of progressive systemic chordoma • 5 patients died from chordoma
Case Example • 62F presented with odynophagia secondary to a C3 chordoma • Single-fraction 24 Gy with surgery planned 3 months after SRS • Patient elected to defer surgery and 3-year MRI shows decrease in tumor size
Toxicity • Grade 1 skin reaction (temporary erythema) • Grade 1 or 2 odynophagia (temporary) • Sciatic neuropathy (foot drop and neuropathic pain) • Tumor encased the sciatic nerve • Partial vocal cord paralysis (vocal cord augmentation)
Limitations • Short follow-up • Heterogeneous group
Conclusions • Single-fraction SRS can be safely used to treat patients with chordomas of the mobile spine and sacrum. • Single-fraction SRS provides good short-term tumor control. • Long term follow-up will be necessary in order to determine if SRS can be used as definitive chordoma therapy or as a neoadjuvant or adjuvant treatment. • Single-fraction SRS represents a good treatment option in patients who cannot undergo wide-margin chordoma excision.