I'm fairly certain that your father was in a battalion medical detachment for the 393rd Infantry Regiment.
The reference that Lois provided says that CPT McIntyre was a BN surgeon. This is a common reference of the Medical Officer in charge of BN medical detachment NOT for a Medical BN.
I was able to find this information
There were no material changes in the authorized Medical Department enlisted strength throughout the year with the exception of a decrease of seventeen Privates Basic (521) authorized by Section III, War Department Circular # 266 dated 29 July 1944. The enlisted strength as of 1 January 1944 was 827 and fluctuated only slightly during the ensuing four months. Thereafter enlisted strength was maintained at authorized Table of Organization level. Upon arrival in the European Theater of Operations the enlisted strength was 867 but had dropped to 725 by 31 December 1944 as a result of battle losses. Medical Department losses during the period 9 November to 31 December were as follows :
UNIT KIA-O/EM MIA-O/EM WIA-O/EM NBC-O/EM TOTAL
393rd 0/0 2/37 0/8 0/10 2/55
394th 0/0 0/29 0/5 0/13 0/47
395th 0/0 0/1 0/8 3/9 3/18
99th ID 0/0 0/1 0/1 0/1 0/3
324th Arty 0/0 0/1 0/1 0/1 0/2
324th Med 0/0 0/8 0/11 0/22 0/41
99th ST 0/0 0/0 0/0 0/0 0/0
Total 0/0 0/76 0/34 3/56 5/166
One complete infantry medical section with forty casualties in the aid station was overrun by the enemy on 17 December 1944. In another instance, a group of 14 enlisted men out of a regimental headquarters medical section were overrun by the enemy.
Here is the reference link
. If you notice the chart only shows two MIA medial officers - both of which were in teh 393rd. Just need to look for a history of the 393rd Inf Regt now.