Yes, I think the vast majority of folks here will tell you that radiation side effects continue to worsen after radiation ends. Everybody is different but the going rate seems to be about 3-6 weeks after treatment ends. For me it got worse for about 5 weeks after treatment, and then it seemed to level off and started to get better.
It can be really demoralizing because you go into it thinking that when treatment ends you'll finally get relief - but it doesn't typically happen that way. BUT - if you can just get past that several weeks, it DOES get better. Just when you think it won't, it does get better.

Best of luck to you. Hopefully your husband will be on the shorter side of recovery.

-steve

Age 41 - Stage 2 SCC tongue Dx 2/06. Cisplatin x3, IMRT x35. Mets to neck node discovered 7/07. RND 40 nodes removed, margins not clear. Cisplatin, Taxotere, 5-FU Fall 07, then IMXT/Erbitux for 7 wks. Inoperable mets to both lungs and pleura Dx Oct'08. 4 cycles Carboplatin, Erbitux, 5-FU so far.