Effectiveness of Radiotherapy in Myxoid Sarcomas is Associated with a Dense

Vascular Pattern

• Ronald de Vreeze, research physician

• Daphne de Jong• Fiona Stewart• Rick Haas• Frits van Coevorden

• Liposarcoma 20% of all malignancies in adults

• Localisation– extremities (75%)– retroperitoneal (10%)– trunk (10%)

Introduction

Introduction

• Target area limitation easier• Lower dose• Canadian SR2 trial (Lancet 2002)

PrePost

Pre vs post operative radiotherapy 50 Gy 66 Gy

– comparable local control 93% 92%

– early complications 35%17%

– late complications 23% 36%

Pre operative radiotherapy

Introduction

• Target area limitation easier• Lower dose• Canadian SR2 trial (Lancet 2002)

PrePost

Pre vs post operative radiotherapy 50 Gy 66 Gy

– comparable local control 93% 92%

– early complications 35%17%

– late complications 23% 36%

Pre operative radiotherapy

Introduction

• 2 studies myxoid liposarcoma show volume reduction after pre-operative radiotherapy

– Pitson et al 2004– Engström et al 2007

• Mechanism is unknown

Pre operative radiotherapy

Introduction

• To investigate histopathological response to preoperative radiotherapy

Purpose

Introduction

• 70 yr male• Progressive circumference calf• No pain or neuro-vascular disability

Patiënt P.

Introduction

• 70 yr male• Progressive circumference calf• No pain or neuro-vascular disability

MLS

WLS-like

Patiënt P.

Introduction

Biopsy

Myxoid Liposarcoma intermediate grade

Pre-operative 50Gy radiotherapy

Introduction

Methods• All pre-operative irradiated sarcomas 2002 - 2006

• Intermediate/high grade sarcomas

• No prior therapy

• 50 Gy

Study pre-operative radiotherapy

Methods

Results• 31 Patiënts 15 ♂ / 16 ♀

• Localisation leg 24 (78%)

• Median tumor Ø 9 cm (3-18)

• Grade intermediate/high 19 / 12

• Early complications 2

Study pre-operative radiotherapy

Results

Pt Histology Response

1234567891011121314151617181920

MLSMLSMLSMLSMLSMLSMLSMLSMLS/ALT-likePleomorphic MFHPleomorphic MFHPleomorphic MFHPleomorphic MFHPleomorphic MFHPleomorphic MFHSynovial sarcomaFibromyxo sarcomaPleomorphic MFHMPNSTPleomorfic liposarcoma

100 100100100100100100100100/09090909090909080808080

Pathologic respons after radiotherapy

Results

Pt Histology response

2122232425262728293031

MLS/RLSLeiomyosarcomaLeiomyosarcomaLeiomyosarcomaPleomorphic MFHSynovial sarcomaSynovial sarcomaSynovial sarcomaChondro sarcomaClear cell sarcomaClear cell sarcoma

66/665050505050505040100

• All pure MLS 100% pathologic response

• 20 of 31 sarcomas > 80% pathologic response

• Arteriolar vascular damage in areas of response

• Similar MLS-like vascular damage in allresponding sarcomas

Results

Results

MLS

WLS-like

Patiënt P.

Results

MLS pre and post radiotherapy

Results

Vascular changes

Results

Arteriolar damage

Thrombosis and arteriolar damage

Histology border MLS/WLS

Viable

Non-Viable

Results

• Pre-operative radiotherapy in vascular sarcomas results in effective pathologic response

• MLS is a radio sensitive sarcoma– All MLS-like sarcomas are sensitive

• The sensitivity seems associated to vascular structure of sarcomas

Conclusions

Conclusions

1) O'Sullivan B, Davis AM, Turcotte R, Bell R, Catton C, Chabot P, Wunder J, Kandel R, Goddard K, Sadura A, Pater J, Zee B. Preoperative versus postoperative radiotherapy in soft-tissue sarcoma of the limbs: a randomised trial. Lancet 2002 June 29;359(9325):2235-41.

2) Pitson G, Robinson P, Wilke D, Kandel RA, White L, Griffin AM, Bell RS, Catton CN, Wunder JS, O'Sullivan B. Radiation response: an additional unique signature of myxoid liposarcoma. Int J Radiat Oncol Biol Phys 2004 October 1;60(2):522-6.

3) Engstrom K, Bergh P, Cederlund CG, Hultborn R, Willen H, Aman P, Kindblom LG, Meis-Kindblom JM. Irradiation of myxoid/round cell liposarcoma induces volume reduction and lipoma-like morphology. Acta Oncol 2007;46(6):838-45.

References

Extra Figures