[R] AFT model

[tsn4867]

     Hi,
  In the package survival, using the function survreg for AFT model, I 
only see 4 distributions for the response y:  weibull, gaussian, 
logistic, lognormal and log-logistic, which correspond to certain 
distributions for the error terms. I'm wondering if there is a package 
or how to obtain the parameter estimates (the beta's are of great 
interest) from the AFT model (maximizing log-likelihood with censored 
data as in Klein and Moeschberger book) if we have
1) error ~ Cauchy(0,1)
2) error comes from a contaminated gaussian dist., for example,
density of error, f(x) = 0.9*phi(x, mean=0, sd=1) + 0.1*phi(x, mean=0, 
sd=3), where phi(.) is the standard gaussian pdf.

                                                                                          
Thank you,
                                                                                        
T.N.