Table 2.

Recurrence disease of NB during maintenance treatment

Time point of recurrence	Total cases (n = 36)
with 13-cis-retinoic acid	31
the first-three months	5
next 6–9 months	26
after 13-cis-retinoic acid stopped	5
3–6 months	2
6–12 months	2
Over 12 months	1