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

Uniform Intensity Intensity Modulation

Conventional RT vs. IMRT

IMRT3-D

Introduction

%

GTVPTV

GTVPTV

Hong et al Int J Rad Oncol Biol Phys, 2004

Planning Tumor Volume (PTV)

IMRT(%)

3DCRT(%)

RATIO %(IMRT/3D)

D95 97 ± 2 97 ± 3 100 ± 1 (p = 0.8)

V95 96 ± 2 96 ± 2 100 ± 1 (p = 0.9)

D05 110 ± 2 110 ± 2 99 ± 2 (p = 0.2)

Hong et al Int J Rad Oncol Biol Phys, 2004

(a) PTV1

Dose (%)0 20 40 60 80 100 120

Vol

ume

(%)

0

20

40

60

80

100

IMRT 3DCRT

Dose Volume Histogram (DVH)

DVH: Femur

IMRT 3DCRT RATIO (IMRT/3D)

V95 35 ± 17(%)

57 ± 20(%)

60 ± 18 %(p = 0.006)

D05 104 ± 2(%)

107 ± 3(%)

97 ± 2 %(p = 0.01)

Dmean 42 ± 12(Gy)

45 ± 14(Gy)

95 ± 9 %(p = 0.1)

Hong et al Int J Rad Oncol Biol Phys, 2004

(b) Femur

Dose (%)0 20 40 60 80 100 120

Vol

ume

(%)

0

20

40

60

80

100

IMRT3DCRT

DVH: Soft Tissue

IMRT 3DCRT RATIO (IMRT/3D)

V95 7 ± 5(%)

23 ± 10(%)

31 ± 15 %(p = 0.002)

D05 96 ± 6(%)

108 ± 2(%)

89 ± 6 %(p = 0.002)

Dmean 25 ± 5(Gy)

25 ± 8(Gy)

102 ± 19 %(p = 0.7)

Hong et al Int J Rad Oncol Biol Phys, 2004

(c) Soft Tisuses

Dose (%)0 20 40 60 80 100 120

Vol

ume

(cc)

0

500

1000

1500

2000

2500

3000

IMRT3DCRT

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 doseto the whole circumference ofbone

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 treatedwith 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

0 I II III IV

6 2 0 0 0

: 8/10: Both developed neurosensory deficit. Both had neurolysis

Grade (CTC)

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

Weekly Status Check

Follow/up Forms

PET Scan For STS

Uniform Intensity Intensity Modulation

Conventional RT vs. IMRT

Uniform Intensity Intensity Modulation

Low intensity over kidney

Conventional RT vs. IMRT