# Calculate Brier score and cindex for AFT model in R

While with Cox PH model, package pec in R provides several useful functions to validate the models based on cindex and brier score, with AFT model, pec does not support object with class survreg. Is there any package in R that can help me calculate Brier score for AFT models?

The psm function in the R rms package is a kind of front-end for survreg in the survival package. psm provides the $c$-index, or at least Somers' $D_{xy}$ that allows you to compute $c$ from the equation $D_{xy} = 2 \times (c - \frac{1}{2})$. It does not provide the Brier score which is used more so for binary $Y$.