secondary liver cancer 4th stage

my brother mitchell was diagnosised with nasophyrengeal cancer and went through chemo and radiation...the cancer left and in 2 months he had a pet scan and found it had spread to his liver...4th stage...oncologist said he had 2 months but with chemo he could streach out his time...he is now in his 4th chemo treatment and would like to do the 30 day cleanse and detox...should he wait till he is through with his chemo treatments he has 4 more or can he start this now...please help we are desperate Tweet