High-dose proton-based radiation therapy in the management of spine chordomas: outcomes and clinicopathological prognostic factors.
OBJECTIVE
Spinal chordomas can have high local recurrence rates after surgery with or without conventional dose radiation therapy (RT). Treatment outcomes and prognostic factors after high-dose proton-based RT with or without surgery were assessed.


METHODS
The authors conducted a retrospective review of 126 treated patients (127 lesions) categorized according to disease status (primary vs recurrent), resection (en bloc vs intralesional), margin status, and RT timing.


RESULTS
Seventy-one sacrococcygeal, 40 lumbar, and 16 thoracic chordomas were analyzed. Mean RT dose was 72.4 GyRBE (relative biological effectiveness). With median follow-up of 41 months, the 5-year overall survival (OS), local control (LC), locoregional control (LRC), and distant control (DC) for the entire cohort were 81%, 62%, 60%, and 77%, respectively. LC for primary chordoma was 68% versus 49% for recurrent lesions (p = 0.058). LC if treated with a component of preoperative RT was 72% versus 54% without this treatment (p = 0.113). Among primary tumors, LC and LRC were higher with preoperative RT, 85% (p = 0.019) and 79% (0.034), respectively, versus 56% and 56% if no preoperative RT was provided. Overall LC was significantly improved with en bloc versus intralesional resection (72% vs 55%, p = 0.016), as was LRC (70% vs 53%, p = 0.035). A trend was noted toward improved LC and LRC for R0/R1 margins and the absence of intralesional procedures.


CONCLUSIONS
High-dose proton-based RT in the management of spinal chordomas can be effective treatment. In patients undergoing surgery, those with primary chordomas undergoing preoperative RT, en bloc resection, and postoperative RT boost have the highest rate of local tumor control; among 28 patients with primary chordomas who underwent preoperative RT and en bloc resection, no local recurrences were seen. Intralesional and incomplete resections are associated with higher local failure rates and are to be avoided.
Departments of 1 Radiation Oncology.
Ronny L
RL
Rotondo
Departments of 1 Radiation Oncology.
Wendy
W
Folkert
Departments of 1 Radiation Oncology.
Norbert J
NJ
Liebsch
Departments of 1 Radiation Oncology.
Yen-Lin E
YL
Chen
Orthopedic Surgery, and.
Frank X
FX
Pedlow
Orthopedic Surgery, and.
Joseph H
JH
Schwab
Pathology, and.
Andrew E
AE
Rosenberg
Pathology, and.
G Petur
GP
Nielsen
Division of Biostatistics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Jackie
J
Szymonifka
Orthopedic Surgery, and.
Al E
AE
Ferreira
Orthopedic Surgery, and.
Francis J
FJ
Hornicek
Departments of 1 Radiation Oncology.
Thomas F
TF
DeLaney
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002817:Chordoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D013904:Thoracic Vertebrae; D016896:Treatment Outcome; D055815:Young Adult
CTV = clinical target volume; DC = distant control; EFS = event-free survival; GTR = gross-total resection; LC = local control; LRC = locoregional control; NCI CTCAE = National Cancer Institute Common Terminology Criteria for Adverse Events; OS = overall survival; RBE = relative biological effectiveness; RC = regional control; RT = radiation therapy; STR = subtotal resection; chordoma; oncology; radiation therapy; sacrum; spine; surgery