The present invention provides a diagnostic agent for a therapeutic effect on cancer, containing a compound represented by formula (1-0). (In formula (1-0), R represents -O(CH 2 ) n -, -O(CH 2 ) n OC 2 H 4 -, -CH 2 O(CH 2 ) n -, or -CH 2 O(CH 2 ) n OC 2 H 4 -, n represents an integer of 1 to 5, and Q 1 represents F or -OCH 3 .)