Janet Eary1, Janet O'Sullivan3, Finbarr O'Sullivan3, E. U. Conrad2

1. Nuclear Medicine/Radiology, University of Washington, Seattle, WA, United States.

2. Orthopedics, University of Washington, Seattle, WA, United States. 3. Statistics, University College Cork, Cork, Ireland

STATISTICAL RISK ANLAYSIS FOR CLINICAL OUTCOMES USING MID-

THERAPY FDG PET IN SARCOMA PATIENTS

UW Soft Tissue Sarcoma Treatment Protocol

Large Intermediate and High grade Tumors

pre-resection 4 chemotherapy cycles

Tumor resection

4 additional cycles of chemotherapy

3 FDG PET scans to monitor response

18FDG is the most important PET procedure

2-fluoro-2-deoxy-D-glucose

• FDG reflects altered tissue metabolism

More than just “grading” images.

Study Patients

Variable Number of patients

Age diagnosis

Pediatric (10-20 years)

22

Adult (21-66 years)

43

Variable Number of patients

Tumor locations

Upper Extremity 8

Lower Extremity 36

Pelvis 14

Trunk 7

Variable Number of Patients

Tumor type

Ewings’ sarcoma

10

Osteosarcoma 15

Fibrosarcoma 1

Leiomyosarcoma

7

Liposarcoma 6

MPNST 5

Sarcoma NOS 13

Synovial sarcoma

8

High Grade Sarcoma: Heterogeneous Response to Chemotherapy

: Study : Design : Analysis :

Aims: determine the value of the mid-therapy FDG PET scan for risk assessment for outcome

Hypothesis: the mid-therapy FDG PET scan will add predictive value to outcome prediction

Methods:

Prospective study

Univariate, and multivariate analyses with Cox proportional Hazards analysis, and models for variables for data reduction

Creation of clinical risk scenarios for different sets of clinical variable combinations

Overall Survival (Univariate Models)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.24 0.23

SUV diff 0.64 0.03

Tumor Size 1.51 0.01

Age 1.40 0.11

Gender 1.11 .80

Tumor type (bone vs soft tissue

0.03 0.02

Tumor Grade 1.01 0.98

Tumor site (trunk vs extremity

2.63 0.02

Overall Survival (reduced model)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.46 0.04

SUVdiff 0.56 0.01

Tumor site(trunk vs extremity)

2.37 0.04

Progression-free Survival(Reduced model)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.33 0.12

SUVdiff 0.55 0.006

Tumor site(trunk vs extremity)

2.93 0.003

Local Progression-free Survival(reduced model)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.78 0.006

SUVdiff 0.49 0.013

Tumor site(trunk vs extremity)

3.24 0.010

Survival

Survival (reduced model)

Overall Survival Progression-free SurvivalLocal Progression-free Survival

Survival Risk (multivariate model)

Extremity tumors Truncal tumors

Local Progression-free Survival(Multivariate model)

Extremity tumors Truncal tumors

FDG PET Risk Assessment in Sarcoma

Conclusions: The mid-therapy scan provides additional information

for risk assessment based on FDG PET and clinical variables

In addition to overall and progression-free survival, local recurrence risk can be assessed

Reduced Hazards and multivariate models for risk assessments provide clinically useful data on an individual patient.

Future Directions: Comparison/inclusion of other risk assessment models

into these analysis results Descriptions of tumor subtype and specific responses to

therapy types. Use of tumor image regional analysis to assess areas at

risk for local recurrence and metastases

Support your local Molecular

Imaging Center !(thanks.)

Progression-Free Survival (univariate models)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.08 0.65

SUVdiff 0.63 0.01

Tumor Size 1.46 0.02

Age 1.28 0.17

Gender 1.41 0.36

Tumor type(bone vs soft tissue)

0.27 0.004

Tumor Grade 0.78 0.50

Tumor site(trunk vs extremity)

3.08 0.002

Local Progression-free Survival(Univariate models)

Variable Hazard Ratio P-value

Pre-therapy SUVmax 1.47 0.04

SUVdiff 0.66 0.08

Tumor size 1.70 0.003

Age 1.28 0.26

Gender 1.05 0.92

Tumor type(bone vs soft tissue)

0.40 0.07

Tumor grade 0.96 0.94

Tumor site(trunk vs extremity)

3.51 0.005

Progression-free Survival(Multivariate model)

Extremity Tumors Truncal Tumors

Survival Risk

Survival- extremity tumors Survival- truncal tumors