An Imaging Agent (Fluorodopa F 18) With Positron Emission Tomography/Magnetic Resonance Imaging for Assessing Treatment Response in Patients With High-Grade Soft Tissue Sarcomas

Correlated with pathologic response. The correlation between imaging measures and pathologic response will be evaluated using a logistic regression model for each one of the four imaging modalities separately. For each subject, 12-18 measures will be taken, and therefore, an exchangeable correlation structure will be used to model the correlation among the measures from the same patient. Giving the exploratory nature of the study, will not adjust for the multiple comparisons. Pathologic responses and imaging measurements will be summarized using point estimates, and 95% confidence interval as well, for each of the four imaging modalities.

Pre-radiation therapy and post-radiation therapy 18F-DOPA PET activity will be correlated with pathologic response. The correlation between imaging measures and pathologic response will be evaluated using a logistic regression model for each one of the four imaging modalities separately. For each subject, 12-18 measures will be taken, and therefore, an exchangeable correlation structure will be used to model the correlation among the measures from the same patient. Giving the exploratory nature of the study, will not adjust for the multiple comparisons. Pathologic responses and imaging measurements will be summarized using point estimates, and 95% confidence interval as well, for each of the four imaging modalities.

Pathologic evaluation of resected specimens by an expert pathologist will be the gold standard for tumor diagnosis and treatment response assessment in this study. Following definitive surgery, the tumor should be examined to determine pathologic response. Since the effect of the preoperative RT may not be uniform throughout the tumor, adequate sampling is required to grade the pathologic response accurately. Tumor's pathologic response will be performed utilizing the grading system below as a guideline: grade I is defined as the percentage of necrosis less than 50%, grade II is defined as the 50%-89% necrosis in the sample, grade III is defined as 90% - 99% necrosis and grade IV is defined as 100% necrosis. The pathological endpoint is defined as the indicator of whether the percentage of necrosis is > 90%.

Imaging endpoints include SUV uptake value mean characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.

Imaging endpoints include SUV maximum characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.

Imaging endpoints include tumor to normal SUV characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.

Imaging endpoints include total metabolic tumor volume characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.

Imaging endpoints include total tumor glycolysis characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.

Imaging endpoints include tumor histogram characteristic. Five patients will be enrolled before RT for additional PET scan for comparison of pre-RT and post-RT SUV metrics, correlated with pathology after surgery, for evaluation of 18F-DOPA PET as a marker for response assessment.