portal film; verification image
Technical term in radiotherapy for an image taken to verify patient positioning before treatment. Also used more broadly for any matching or verification photograph.
See also: 確認写真
In radiotherapy, the treatment position is verified using a portal film.
We take a verification image to check whether the patient's position is correct.
確認写真 is a broader term for any confirmation photo, while 照合写真 specifically implies matching against a reference, often in medical or technical contexts.
Compound of 照合 (matching, verification) and 写真 (photograph).