Patient selection: malignancy in the head of the pancreas
Parameters:
(1) time to surgery in days
(2) serum CA19-9 in kunits per liter
(3) jaundice
(4) back pain
|
Parameter
|
Finding
|
Points
|
|
time to surgery
|
|
0.0099* (days)
|
|
serum CA19-9
|
|
0.0007 * (CA19-9)
|
|
jaundice
|
absent
|
0.7468
|
|
|
present
|
-0.7468
|
|
back pain
|
absent
|
-1.9239
|
|
|
present
|
1.9239
|
X =
= SUM(points for all 4 parameters) - 0.6489
probability of resectability according to paper =
= 1 / (1 + EXP((-1) * X))
probability of resectability according to on-line calculator =
= 1 - [1 / (1 + EXP((-1) * X))]
Performance:
• The area under the ROC curve is 0.92.
NOTE: A resectable tumor should be associated with a short time to surgery, low CA19-9, jaundice and no back pain. When this is placed in the model, a low percentage is returned. This suggests that the probability is for the tumor to be unresectable. This is confirmed by results given by the on-line calculator at www.uhb.nhs.uk/prediction-of-resectability-calculator.htm.
