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Probability of Cancer in Pulmonary Nodule - Parsimonious for Spiculated Mass

Purpose: To use the parsimonious model of McWilliams et al to predict cancer in a spiculated mass seen on a first screening CT.

Description

McWilliams et al developed models for predicting cancer in a pulmonary nodule seen on a first screening CT. Two models are for a spiculated mass, one parsimonious and one a full model. The authors are from multiple institutions in Canada, the United States and Argentina.


Data modifications:

(1) age: 62 is subtracted from the actual age

(2) nodule size: 4 mm is subtracted and then transformed (below)

(3) number of nodules: 4 is subtracted

 

nodule size transformation =

= (((nodule size after modified) / 10)^(-0.5)) - 1.58113883

 

Parameters for parsimonious model:

(1) sex

(2) nodule size

(3) nodule location

(4) spiculation

 

Parameter

Findings

Points

sex

male

0

 

female

0.6467

nodule size

 

-5.5537 * (size)

nodule location

upper

0.6009

 

middle or lower lobe

0

spiculation

yes

0.9309

 

no

0

 

value of X =

= SUM(points for the 3 parameters)-6.6144

 

probability of cancer =

= 1 / (1 + EXP((-1) * X))


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Specialty

Objective

ICD-10