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UHN. IMRT, Designed with Evidence-Based Bone Avoidance Objectives, Reduces the risk of Bone Fracture in the management of Extremity Soft Tissue Sarcoma. Princess Margaret Cancer Center. Colleen Dickie MSc, MRT(T)(MR) Assistant Professor, University of Toronto. Acknowledgements. - PowerPoint PPT Presentation
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IMRT, Designed with Evidence-Based Bone Avoidance Objectives, Reduces the risk of
Bone Fracture in the management of Extremity Soft Tissue Sarcoma
Colleen Dickie MSc, MRT(T)(MR)Assistant Professor, University of Toronto
UHNPrincess Margaret Cancer Center
Acknowledgements
Anthony M. Griffin, MScAmy Parent, MRT(T), BSc, CMDMichael B. Sharpe, PhDPeter C. Ferguson, MD, FRCSCJay S. Wunder, MD, FRCSCPeter Chung, MD, FRCPCCharles N. Catton, MD, FRCPCBrian O’Sullivan, MD, FRCPC
Princess Margaret Cancer Center
Background
Holt et al. Fractures following RT and Limb-Salvage Surgery for LE-STS: JBJS 2005
Sternheim et al. Internal fixation …high rate of failure: Bone Joint J 2013;95-B:1144–8.
• Severe morbidity Review of 22 pts with internal fixation for fracture
Complications in 86% (82% non union at 12 mos) 13 pts underwent 24 revision operations
• 364 LE-STS EBRT Females, > 55 yrs, thigh tumor locationPeriosteal stripping High (60-66 Gy – 10 %) vs. Low (50 Gy -2%)Overall – 6.3 % crude riskMedian F/U = 58 mos
Background• 1989 - 2004• Lack of 3D info• 21 pts 24 fractures: 53 control
Matched on gender, tumour size /
location, age, beam arrangement, RT
timing / RT dose
• Fracture Risk reduced if: V40 kept below 64% Mean bone dose < 37 Gy Max bone dose < 59 Gy
Dickie et al. Bone Fractures following EBRT… IJROBP 2009 Nov 15;75(4):1119-24.
Objective
• To evaluate the potential for IMRT to reduce the risk of bone fractures: Lower extremity soft tissue sarcoma (LE-STS) Combined modality local treatment
• Evidence based Bone Avoidance Objectives (BAO) V40 kept below 64% Mean bone dose < 37 Gy Max bone dose < 59 Gy
Dickie et al. Bone Fractures following EBRT… IJROBP 2009 Nov 15;75(4):1119-24.
Methods / Materials• Study timeframe: 2005 – 2011
• 230 plans employed BAO from our previous study 176 lower extremity 54 upper extremity
• Study confined to weight bearing bones to minimize reporting bias i.e. Removed upper extremity cases (176 LE-STS)
• All patients: Surgery combined with RT 155 received preop (50 Gy) 21 received postop (60 – 66 Gy) 2 Gy per fraction daily
Methods / Materials• 4 patients re-irradiated for in field recurrent disease
44 Gy / 40 fractions BID 6 hours apart
• 5 patients re-irradiated for recurrent disease at edge 50 Gy in 25 fractions
• We evaluated: Mean bone dose Max bone dose Volume of Bone receiving > 40 Gy (V40) Mean dose to the clinical target volume (CTV dose)
Results
• Target Coverage Criteria 100 %• BAO achieved: 96 % preop, 72 % postop RT plans• 4 patients experienced a bone fracture (2.2 %)
All preop 50 Gy / 25 f, 1 further 44 Gy / 40 f 3 males, 1 female
• Mean F/U= 47 mos
Dose (Gy) Preoperative RT Postoperative RT Re-irradiation
Mean Bone 25.9 + 9 31.4 + 13 24.4 + 11
Max Bone 49.1 + 4 55.4 + 13 48.3 + 13
V40 (%) 32.3 % 37.3 % 27.5 %
Mean CTV 50.6 + 1 64.9 + 2 51.1 + 6
9
First Fracture Case• 46 yr old Male - Crane operator• Myxoid Liposarcoma Rt Calf• Preop RT & Sx 2007• 15 mos post Tx spiral fracture• Trauma by metal crane ring
within RT volume• > 58 Gy coincided with fracture
site• Treated conservatively
20082011
High dose >58Gy
2007
CTV mean = 50.9 GyBone mean = 30.6 GyBone max = 58.7 GyBone V40 = 37 %PASSED
10
Second Fracture CaseOriginal
Retreat
10 cm
• UPS RT Thigh
• 55 yr Male
• Preop RT 2008
• Sx 2009
• In- field recurrence 2010
• Retreatment Second RT
course: IMRT 44 Gy / 40
11
Second Fracture Case• Proximal femur fracture
2012- fall at home
• 41 mos post Tx
• IM nail / Iliac crest bone
graft
• 6 mos no healing
• Cemented proximal femur
tumor prosthesis 2013
2012
2013
1st PlanCTV = 51.7 GyBone mean = 35.5 GyBone max = 49.8 GyBone V40 = 31 %
BID planCTV = 40 GyBone mean = 15 GyBone max = 35 GyBone V40 = 1 %
Third Fracture Case
• 63 yr old Male• Fibrosarcoma RT Thigh• Preop RT & Sx 2007• Disease > 60%
circumferential• Fall - Fracture May
2008• IM nail inserted
GTV
High RT dose
FAILEDCTV mean 52.7 GyBone mean 41.4 GyBone max 52.9 GyBone V40 75.9 %
13
Fourth Fracture Case
• UPS RT thigh
• 57 yr Female
• Preop RT
• Disease > 60%
Circumferential
• 19 mos post Tx- pain
• Undisplaced transverse
fracture
• IM nailGTVCTV mean = 51.9 Gy
Bone mean = 26.1 GyBone max = 53.7 GyBone V40 = 39 %PASSED
Conclusions• Risk of fracture using BAOs is lower than previously reported
(2.2 % vs. 6.3 %)• Preferential use of preoperative RT
adverse RT morbidities RT volumes and doses
• Bone objectives are practical and beneficial• Bone sparing techniques should be employed for:
Circumferential disease In re-irradiation settings For women > 55 yrs
AcknowledgementsAnthony M. Griffin, MSc
Amy Parent, BSc, MRT(T)Michael B. Sharpe, PhD
Peter C. Ferguson, MD, FRCSCJay S. Wunder, MD, FRCSCRobert S. Bell, MD, FRCSCPeter Chung, MD, FRCPC
Charles N. Catton, MD, FRCPCBrian O’Sullivan, MD, FRCPC
Princess Margaret Cancer Center