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ADC Calculations

Lars Ewell

Radiation Oncology University of Arizona Medical Center

2/8/08

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ADC Across Slices

• ADC needed for entire lesion, NOT for single contour.

• Area/Volume needs to be accounted for.

• Slice spacing also can affect values.

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Imaging Protocol: First Patient• Given standard treatment for GBM(resected):

2Gy/Fx 23 Fx (46Gy) + 2Gy/Fx 17 Fx (14Gy). Tx finished on 2/19/07. Total of 60Gy. This Tx alone would have enabled enrollment in protocol.

• Prescribed additional dose of 15 Gy to same area via Stereotactic Radio Surgery (SRS). Patient at high risk for radiation necrosis. Enrolled/scanned on 3/23/07. Scan time 1 hr 13min.

• Treated with 15 Gy additional radiation on 3/28/07.

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MRI Scans Used for Contouring: T2 FLAIR (?)

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MRI Scans Used for ADC Calculation – diffrad, b=0

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Comparison of Scans

• T2 FLAIR/Brainscan Vlesion=9.14cc

• b=0 Protocol Scan Slice Thickness = 5mm

• b=0 Protocol Scan Slice Spacing = 7mm