Thanks for the info. You would never bill 77412 for the physician in POS 22. That's the radiation treatment delivery, and it is a technical (facility) only charge.
On a treatment delivery date, the only thing that the physician would bill is the professional component for any image guidance performed, and the treatment management code. From the details in your original post, the image guidance would be the G6002-26. There are other types of image guidance that would use different codes - I'm sticking with the G6002 from your original post for this example.
(Remember that to bill the image guidance, it must be ordered by the physician in the treatment planning document. The images must also be reviewed and approved before the next visit or they are non billable. Ex - if the patient has daily treatments Monday - Friday, Monday's images must be signed off before Tuesday's treatment, Tuesday's images must be signed off before Wednesday's treatment, etc. If the physician hasn't reviewed and approved the image before the next day's treatment, you can't bill for the image guidance.)
The physician is compensated for the supervision of treatment delivery by billing the treatment management code. 77427 would be billed once every 5 treatments. If the physician has performed and documented the weekly On Treatment Visit (OTV) with the patient, which they should be doing when the patient is in the treatment stage.
(77427 the treatment management code that would correlate with the facility's treatment delivery 77412. There are other treatment management codes for SBRT/SRS, or treatment delivery when the entire course of therapy consists of only 1 or 2 fractions.)
Assuming that the images are approved timely and the physician is documenting the OTV, this is what you would generally bill for the physician for 5 days of treatment delivery:
Day 1: G6002-26
Day 2: G6002-26
Day 3: G6002-26
Day 4: G6002-26
Day 5: 77427, G6002-26