Optimizing GPT-5 for Operation-Procedure-Code-Extraction from Operative Reports in Meningioma Surgery: Feasibility and Comparison of Context-Enhancements.

Non context enhanced GPT-5s showed the lowest rate of correct coding (44%) and highest number of hallucinations (105) and total mistakes (132).

GPT-5o showed identical accuracy to GPT-5s (44%, p = 1.0), but fewer hallucinations (51, p = 0.002) and mistakes (78, p = 0.008).

Highest coding accuracy was achieved by GPT-5c (GPT-5c vs GPT-5r, p = 0.143, GPT-5c vs GPT5e p = 0.008).

GPT-5r and GPT-5e performed equally regarding accuracy, GPT-5r produced fewer mistakes ( p = 0.034), while GPT-5e hallucinated less ( p = 0.057).