husband's treatment break in chemo / waiting for scan /weight loss

well, my husband has now completed two rounds of chemo - carboplatin and irinotecan.
before that ( have posted previously ) had 22 radiation treatments to lung tumor. and two lesions on vertebrae 10 and 12 .first scan after original chemo - carbo and etopisde showed no change therefore, change in chemo "cocktail". hoping this scan ,which will be on 12/27 will show anything positive. shrinkage or better.
the absolute hardest thing for him is looking in the mirror. he has lost so much weight, mostly muscle,fat,too.
he isn't a big guy. orginal weight before all of this was around 148 to 152 lbs.
was diagnosed in august at 146 lbs. and is down to 126 at this time.
during radiation, he started at 133 and ended at 134.has lost the most, during chemo. never vomitted but, no appetite until last few days. pumped him up with allhigh calorie/protein drinks which he handled well.
has anyone experiences significant weight loss and loss of appetite during chemo treatments ? did weight return once appetite returned ? i'm so worried about his weakness. docs tell us they think he's doing pretty well for someone with sclc. blood workups are taken at least twice a month since august - if not more at certain times. and, all were good and never needed transfusions, iv fluids or a break in any treatment.
any comments/suggestions are welcome.

bancroft