Introduction: Commercial software platforms, such as Brainlab Elements™ utilize postoperative Computed Tomography (CT) to estimate deep brain stimulation (DBS) lead orientation. The iron-sight method on rotational fluoroscopy offers a potentially accurate and accessible alternative, but its interobserver agreement and validity in clinical settings remain unverified. Objective: To evaluate inter-observer agreement in estimating lead orientation using the iron-sight method on postoperative rotational fluoroscopy and to compare these estimates with Brainlab Elements™ from postoperative CT. Methods: This prospective study included 70 leads in patients who underwent DBS implantation with directional leads at a tertiary care center between 2022 and 2024. The inter-rater agreement of independent measurements obtained by two observers utilizing the iron-sight method was evaluated. Subsequently, these measurements were compared with those derived from the Brainlab Element™ software. Results: Bland–Altman analysis of measurements between observers revealed a mean bias of 0.68° (95% CI: –0.0678° to 1.4335°), with limits of agreement from –5.49° (CI: –6.79° to –4.19°) to 6.85° (CI: 5.55° to 8.15°). The Preiss–Fisher test confirmed that the agreement was statistically significant and unlikely to be due to chance. (Z = –15.78, P < 0.001). In the method comparison (n = 67), the mean bias was –0.69° (95% CI: –2.48° to 1.10°), with limits of agreement ranging from –14.86° (95% CI: –17.97° to –11.76°) to 13.48° (95% CI: 10.37° to 16.58°). The Watson–Williams test showed no significant difference in circular means (p = 0.7905). Exploratory regression suggested that coronal and polar lead angles modestly influenced interobserver variability, whereas trajectory angles did not affect method agreement. Conclusion: The iron-sight method is a reliable and reproducible tool for estimating directional lead orientation, with excellent interobserver agreement and good concordance with Elements™ estimates.

The authors have declared no competing interest.

This study was funded by Jaslok Hospital and Research Center, Mumbai, India.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Institutional Ethics Committee of Jaslok Hospital and Research Center, Mumbai gave ethical approval for this work (approval number EC/1114/2022, dated April 29, 2022).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present work are contained in the supplementary material.