An effective preoperative three-dimensional radiotherapy target volume for extremity soft tissue sarcoma and the effect of margin width on local control.
OBJECTIVE
There is little information on the appropriate three-dimensional (3D) preoperative radiotherapy (XRT) volume for extremity soft-tissue sarcomas (STS). We retrospectively analyzed the pattern of local failure (LF) to help elucidate optimal field design.


METHODS
We analyzed the 56 patients who underwent computed tomography-planned XRT for Stage I to III extremity STS between June 2000 and December 2006. Clinical target volume (CTV) included the T1 post-gadolinium-defined gross tumor volume with 1- to 1.5-cm radial and 3.5-cm longitudinal margins. Planning target volume expansion was 5 to 7 mm, and >or=95% of dose was delivered to the planning target volume. Preoperative XRT was 44 to 50.4 Gy (median, 50). Postoperative boost of 10 to 20 Gy was given to 12 patients (6 with positive and 6 with close margins).


RESULTS
Follow-up ranged from 15 to 76 months (median, 41 months). The 5-year local control, freedom from distant metastasis, disease-free survival, and overall survival were 88.5%, 80.0%, 77.5% and 82.8%, respectively. Three patients (all with positive margin) experienced local failure (LF) as first relapse (2 isolated, 1 with distant failure), and 2 additional patients (all with margin<1 mm) had late LF after distant metastasis. The LFs were within the CTV in 3 patients and within and also extending beyond the CTV in 2 patients.


CONCLUSIONS
These target volume definitions appear to be appropriate for most patients. No local recurrences were observed with surgical margins >or=1 mm, and it appears that these may be adequate for patients with extremity STS treated with preoperative radiotherapy.
Kim
BoKyong
B
Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA.
Chen
Yen-Lin E
YL
Kirsch
David G
DG
Goldberg
Saveli I
SI
Kobayashi
Wendy
W
Kung
Jong Hyun
JH
Wolfgang
John A
JA
Doppke
Karen
K
Rosenberg
Andrew E
AE
Nielsen
G Petur
GP
Raskin
Kevin A
KA
Springfield
Dempsey S
DS
Schwab
Joseph H
JH
Gebhardt
Mark C
MC
Yoon
Sam S
SS
Hornicek
Francis J
FJ
DeLaney
Thomas F
TF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D005121:Extremities / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000601:surgery; D011300:Preoperative Care; D011879:Radiotherapy Dosage; D012509:Sarcoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D017211:Treatment Failure; D047368:Tumor Burden / Q000528:radiation effects; D055815:Young Adult