Int_Orthop_44_381.pdf 508 KB
Fujiwara, Tomohiro Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences ORCID Kaken ID
Tsuda, Yusuke Oncology Service, The Royal Orthopaedic Hospital NHS Foundation Trust
Stevenson, Jonathan Oncology Service, The Royal Orthopaedic Hospital NHS Foundation Trust
Parry, Michael Oncology Service, The Royal Orthopaedic Hospital NHS Foundation Trust
Jeys, Lee Oncology Service, The Royal Orthopaedic Hospital NHS Foundation Trust
Purpose Chordoma is a rare but highly aggressive primary bone sarcoma that arises commonly from the sacrum. While en bloc resection has been the mainstay of the treatment, the role of resection margin in millimetres with/without adjuvant radiotherapy (RT) has been unknown. We investigated the prognostic impact of surgical margin width, adjuvant RT, and their combined factor for sacral chordoma. Methods Forty-eight patients who underwent surgical treatment between 1996 and 2016 were studied. Of these, 11 patients (23%) received adjuvant RT; photon RT in 7 (15%) and proton RT in 4 (8%). Margins were microscopically measured in millimetres from the resection surface to the closest tumour on histologic slides. Results The five year and ten year disease-specific survival was 88% and 58%, respectively, and the local recurrence (LR) rate was 48%. The LR rate with 0-mm, < 1.5-mm, and ≥ 1.5-mm margin was 50% (group 1), 50% (group 2: RT−, 61%; group 3: RT+, 14%), and 0% (group 4), respectively. We observed a significantly lower LR rate in patients with adjuvant photon/proton RT (18%) than without it (57%; p = 0.026), and no LR was observed after post-operative proton RT. The combined factor of margin with RT clearly stratified the LR risk: patients of group 1 (positive margin) and 2 (< 1.5-mm margin, RT−) had approximately 7.5× LR risk (p = 0.049) compared with those of group 3 (< 1.5-mm margin, RT+) and 4 (≥ 1.5-mm margin). Conclusion This study identified the lowest risk of local failure in tumour resection with ≥ 1.5-mm margin or negative but < 1.5-mm margin with the use of adjuvant photon/proton radiotherapy for sacral chordoma. Early results of adjuvant proton RT demonstrated excellent local control.
This is a post-peer-review, pre-copyedit version of an article published in International Orthopaedics. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00264-019-04460-5. This fulltext is available in Dec. 2020.
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