combiner isssues relate to power handling capacity

Hello all
i want help facing problem now;
i would like to design a power combiner at 250W CW at freq of 64 Mhz
i tried some gysel design approach with micro strips mender line on Er 3.5 with thickness of 1.5
s parameter characterization of designed prototype are successful

but some of my friend doubt about the same that whether it will handle such high power
i want help regarding power handling of same

if it not able to handle power which design approach i should consider

for gysel prototype i am considering heat sink calculation also