Tumour Volume and Dose Influence Outcome after Surgery and High-dose Photon Radiotherapy for Chordoma and Chondrosarcoma of the Skull Base and Spine

E R Gatfield; D J Noble; G C Barnett; N Y Early; A C F Hoole; N F Kirkby; S J Jefferies; N G Burnet

doi:10.1016/j.clon.2018.01.002

Tumour Volume and Dose Influence Outcome after Surgery and High-dose Photon Radiotherapy for Chordoma and Chondrosarcoma of the Skull Base and Spine

Clin Oncol (R Coll Radiol). 2018 Apr;30(4):243-253. doi: 10.1016/j.clon.2018.01.002.

Authors

E R Gatfield¹, D J Noble², G C Barnett³, N Y Early⁴, A C F Hoole⁴, N F Kirkby⁵, S J Jefferies³, N G Burnet²

Affiliations

¹ Oncology Centre, Addenbrooke's Hospital, Cambridge, UK. Electronic address: elinor.gatfield@nhs.net.
² University of Cambridge Department of Oncology, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, UK.
³ Oncology Centre, Addenbrooke's Hospital, Cambridge, UK.
⁴ Department of Medical Physics and Clinical Engineering, Addenbrooke's Hospital, Cambridge, UK.
⁵ Division of Molecular and Clinical Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, UK; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK.

PMID: 29402600
DOI: 10.1016/j.clon.2018.01.002

Abstract

Aims: To evaluate the long-term outcomes of patients with chordoma and low-grade chondrosarcoma after surgery and high-dose radiotherapy.

Materials and methods: High-dose photon radiotherapy was delivered to 28 patients at the Neuro-oncology Unit at Addenbrooke's Hospital (Cambridge, UK) between 1996 and 2016. Twenty-four patients were treated with curative intent, 17 with chordoma, seven with low-grade chondrosarcoma, with a median dose of 65 Gy (range 65-70 Gy). Local control and survival rates were calculated using the Kaplan-Meier method.

Results: The median follow-up was 83 months (range 7-205 months). The 5 year disease-specific survival for chordoma patients treated with radical intent was 85%; the local control rate was 74%. The 5 year disease-specific survival for chondrosarcoma patients treated with radical intent was 100%; the local control rate was 83%. The mean planning target volume (PTV) was 274.6 ml (median 124.7 ml). A PTV of 110 ml or less was a good predictor of local control, with 100% sensitivity and 63% specificity. For patients treated with radical intent, this threshold of 110 ml or less for the PTV revealed a statistically significant difference when comparing local control with disease recurrence (P = 0.019, Fisher's exact test). Our data also suggest that the probability of disease control may be partly related to both target volume and radiotherapy dose.

Conclusion: Our results show that refined high-dose photon radiotherapy, following tumour resection by a specialist surgical team, is effective in the long-term control of chordoma and low-grade chondrosarcoma, even in the presence of metal reconstruction. The results presented here will provide a useful source for comparison between high-dose photon therapy and proton beam therapy in a UK setting, in order to establish best practice for the management of chordoma and low-grade chondrosarcoma.

Keywords: Chondrosarcoma; chordoma; local control; radiotherapy; tumour volume.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Chondrosarcoma* / mortality
Chondrosarcoma* / pathology
Chondrosarcoma* / therapy
Chordoma* / mortality
Chordoma* / pathology
Chordoma* / therapy
Female
Humans
Kaplan-Meier Estimate
Male
Middle Aged
Neoplasm Recurrence, Local / radiotherapy
Photons / therapeutic use
Proton Therapy / methods
Radiotherapy / methods*
Skull Base Neoplasms* / mortality
Skull Base Neoplasms* / pathology
Skull Base Neoplasms* / therapy
Spinal Neoplasms* / pathology
Spinal Neoplasms* / therapy
Survival Rate
Tumor Burden

Grants and funding

C20/A20917/Cancer Research UK/United Kingdom