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Intensity Modulated Radiation Therapy For Soft Tissue Sarcoma Of The Extremity: Preliminary Results. KM Alektiar, L Hong, MF Brennan, S Singer. Memorial Sloan-Kettering Cancer Center. Conventional RT vs. IMRT. Uniform Intensity. Intensity Modulation. Introduction. PTV. PTV. GTV. GTV.
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Intensity Modulated Radiation Therapy For Soft Tissue Sarcoma Of The Extremity:Preliminary Results KM Alektiar, L Hong, MF Brennan, S Singer. Memorial Sloan-Kettering Cancer Center
Conventional RT vs. IMRT Uniform Intensity Intensity Modulation
Introduction PTV PTV GTV GTV IMRT 3-D % Hong et al Int J Rad Oncol Biol Phys, 2004
Planning Tumor Volume (PTV) Dose Volume Histogram (DVH) Hong et al Int J Rad Oncol Biol Phys, 2004
DVH: Femur Hong et al Int J Rad Oncol Biol Phys, 2004
DVH: Soft Tissue Hong et al Int J Rad Oncol Biol Phys, 2004
Purpose • To determine the feasibility of IMRT in locally advanced STS of the extremity • To report on treatment related toxicity and tumor control
Patients • # pts: 10 • Site: Extremity • Presentation: Primary STS • Time period: 03/02- 10/03 • Mean age: 58 (range: 40-76) • Sex: 6F/4M
Tumors Characteristics • Grade: High (7/10) • Depth: Deep (10/10) • Median size: 17 cm (9/10, > 10 cm) • Site: Lower extremity (9/10) • Sub-site: Thigh (7/10) Knee, leg, shoulder
Surgery • Complete gross resection: 10/10 • Positive/close margin: 4/10 • Periosteal stripping/bone resection: 6/10 • Neurolysis/nerve resection: 6/10 • Tissue transfer for wound closure: 2/10
Indications For IMRT Preoperative IMRT: 4/10 Preserve normal soft tissue
Indications For IMRT Post-op IMRT: 6/10 To reduce high RT dose to the whole circumference of bone
IMRT Characteristics Median Range Gantry angles 5 2 - 6 Fields 8 2 - 10 MU 882 366 - 1233 : Splitting of RT fields was required in 2 patients.
Complications • Fracture • Significant wound complications • Joint stiffness • Peripheral nerve damage • Edema
Fracture • Median F/U: 13 months (range: 6-22) • None of the patients developed a fracture
Significant Wound Complications None Infection Wound Re-op 8 1 1 : Lower extremity lesion treated with pre-op IMRT to 50 Gy
Joint Stiffness (RTOG) None Mild Moderate Severe 6 1 3 0 : 2/3 had resolution of their stiffness after physical therapy
Peripheral Nerve Damage Grade (CTC) 0 I II III IV 6 2 0 0 0 • : 8/10 : Both developed neurosensory deficit. Both had neurolysis
Edema (CTC) None Mild Moderate Pitting 8 1 1 0 : Patient had a resection of femoral vein at the time of surgery
Tumor Control • Median F/U: 13 months • Local recurrence: 0/10 • Distant relapse: 2/10 • Death: 2/10
Conclusion • IMRT is feasible for STS of the extremity • Initial results suggest limited morbidity and excellent local control • Longer follow/up is still needed to confirm these encouraging results in a difficult group of high-risk patients
Conventional RT vs. IMRT Uniform Intensity Intensity Modulation
Conventional RT vs. IMRT Uniform Intensity Intensity Modulation Low intensity over kidney