A nonrandomized pilot study on malignant glioma patients with pretargeted adjuvant radioimmunotherapy using yttrium90biotin.
1 
A data frame with 37 observations on 7 variables.
no.
patient number.
age
patient age (years).
sex
a factor with levels "F"
(Female) and "M"
(Male).
histology
a factor with levels "GBM"
(grade IV) and "Grade3"
(grade
III).
group
a factor with levels "Control"
and "RIT"
.
event
status indicator for time
: FALSE
for censored observations
and TRUE
otherwise.
time
survival time (months).
The primary endpoint of this small pilot study is survival. Since the survival times are tied, the classical asymptotic logrank test may be inadequate in this setup. Therefore, a permutation test using Monte Carlo resampling was computed in the original paper. The data are taken from Tables 1 and 2 of Grana et al. (2002).
Grana, C., Chinol, M., Robertson, C., Mazzetta, C., Bartolomei, M., De Cicco, C., Fiorenza, M., Gatti, M., Caliceti, P. and Paganelli, G. (2002). Pretargeted adjuvant radioimmunotherapy with Yttrium90biotin in malignant glioma patients: A pilot study. British Journal of Cancer 86(2), 207–212.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36  ## Grade III glioma
g3 < subset(glioma, histology == "Grade3")
## Plot KaplanMeier estimates
op < par(no.readonly = TRUE) # save current settings
layout(matrix(1:2, ncol = 2))
plot(survfit(Surv(time, event) ~ group, data = g3),
main = "Grade III Glioma", lty = 2:1,
ylab = "Probability", xlab = "Survival Time in Month",
xlim = c(2, 72))
legend("bottomleft", lty = 2:1, c("Control", "Treated"), bty = "n")
## Exact logrank test
logrank_test(Surv(time, event) ~ group, data = g3,
distribution = "exact")
## Grade IV glioma
gbm < subset(glioma, histology == "GBM")
## Plot KaplanMeier estimates
plot(survfit(Surv(time, event) ~ group, data = gbm),
main = "Grade IV Glioma", lty = 2:1,
ylab = "Probability", xlab = "Survival Time in Month",
xlim = c(2, 72))
legend("topright", lty = 2:1, c("Control", "Treated"), bty = "n")
par(op) # reset
## Exact logrank test
logrank_test(Surv(time, event) ~ group, data = gbm,
distribution = "exact")
## Stratified approximative (Monte Carlo) logrank test
logrank_test(Surv(time, event) ~ group  histology, data = glioma,
distribution = approximate(B = 10000))

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