Comparison of Postoperative Intensity Modulated Radiation Therapy With 2-Dimensional Radiation Therapy in Patients With Soft-Tissue Sarcoma of Extremities and Trunk

Abstract

To compare directly clinical outcomes and late toxicities of postoperative intensity-modulated radiation therapy (IMRT) with two-dimensional radiation therapy (2D-RT) for patients with soft tissue sarcoma (STS) of extremities and trunk. 145 consecutive patients with non-metastatic STS of extremities and trunk treated with postoperative IMRT (n = 84) and 2D-RT (n = 61) from January 2005 to December 2011 were analyzed. All patients were treated with wide local excision and radiation therapy-naive. Average age was 44.7 years (range, 5-77) and 83 (57.2%) patients were female. The characteristics of the patients were shown in Table 1. The IMRT group had more patients over 50 years (51.2% vs 32.8%; p = 0.029), less proportion of tumors in extremities (64.3% vs 88.5%; p<0.001) and lower median radiation dose (63.2 ± 4.5 Gy vs 66 ± 3.3 Gy; p = 0.014), compared with the 2D-RT group. Other parameters of demographics, disease and treatment characteristics were comparable (p>0.05) between the two groups. The median follow-up time was 46.3 months (39.0 months for patients treated with IMRT and 67.9 months for 2D-RT). Nineteen local recurrences, 40 distant metastases and 30 deaths have occurred. The 5-year actuarial Local control (LC), distant-metastasis free survival (DMFS), disease-free survival (DFS) and overall survival rates (OS) for the cohort were 84.1%, 73.1%, 64.7% and 77.6%, respectively. Compared to 2D-RT group, the IMRT group had higher 5-year LC (87.3% vs 81.4%; p = 0.54), DMFS (75.8% vs 67.9%; p = 0.44), DFS (72.0% vs 58.1%; p = 0.36) and OS (83.0% vs 75.8%; p = 0.74), but without statistically significant differences. On multivariate analysis, large tumor (>5cm) [HR = 2.60 (95% CI, 1.20-5.66); p = 0.016] and disease stage [HR = 1.98 (95% CI, 1.00-3.89); p = 0.05] emerged as independent risk factor of OS, and no factor was identified to be related with LC. In terms of late toxicities, the patients in IMRT group enjoyed lower incidences and less serious edema (10.6% vs 19.7%; p = 0.53) and joint stiffness (9.2% vs 13.0%; p = 0.78) than those in 2D-RT group. Fractures (CTCAE grade 3) were found in 2 patients of 2D-RT group and none in IMRT group. When compared with conventional techniques, postoperative IMRT seems to provide better LC and OS and less severe late toxicities in patients with STS of extremities and trunk, though the differences were not statistically significant. Demographic and treatment characteristics of 145 patients with postoperative IMRT or conventional RTScientific Abstract 3377; TableVariablesNo. of patients (%)VariablesNo. of patients (%)VariablesNo. of patients (%)VariablesNo. of patients (%)VariablesNo. of patients (%)Age(years)PresentationHistologyGradeStage>5063(43.3)primary90(62.1)malignant fibrous histiocytoma31(21.4)G129(20.0)I29(20.0)≤5082(56.6)recurrent55(37.9)liposarcoma31(21.4)G292(63.4)II109(75.2)SexTumor size(cm)synovial sarcoma24(16.6)G324(16.6)III7(4.8)men83(57.2)≤581(55.9)fibrosarcoma26(17.9)MarginDose(Gy)women62(42.8)>564(44.1)rhabdomyosarcoma3(2.1)negative128(88.3)≤6493(64.1)LocationDepthothers30(20.7)Microscopic positive10(6.9)>6452(35.9)extremities108(74.5)superfacial46(31.7)Macroscopic positive7(4.8)trunk37(25.5)deep99(68.3) Open table in a new tab