Mir-Moghtadaei, ArsalanCaballero, RuthFried, PeterFox, MichaelLee, KatherineGiacobbe, PeterDaskalakis, Zafiris J.Blumberger, Daniel M.Downar, Jonathan2016-11-182016Mir-Moghtadaei, Arsalan, Ruth Caballero, Peter Fried, Michael D. Fox, Katherine Lee, Peter Giacobbe, Zafiris J. Daskalakis, Daniel M. Blumberger, and Jonathan Downar. 2016. “Concordance Between BeamF3 and MRI-neuronavigated Target Sites for Repetitive Transcranial Magnetic Stimulation of the Left Dorsolateral Prefrontal Cortex.” Brain stimulation 8 (5): 965-973. doi:10.1016/j.brs.2015.05.008. http://dx.doi.org/10.1016/j.brs.2015.05.008.1935-861Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:29407585Background: The dorsolateral prefrontal cortex (DLPFC) is a common target for repetitive transcranial magnetic stimulation (rTMS) in major depression, but the conventional “5 cm rule” misses DLPFC in > 1/3 cases. Another heuristic, BeamF3, locates the F3 EEG site from scalp measurements. MRI-guided neuronavigation is more onerous, but can target a specific DLPFC stereotaxic coordinate directly. The concordance between these two approaches has not previously been assessed. Objective: To quantify the discrepancy in scalp site between BeamF3 versus MRI-guided neuronavigation for left DLPFC. Methods: Using 100 pre-treatment MRIs from subjects undergoing left DLPFC-rTMS, we localized the scalp site at minimum Euclidean distance from a target MNI coordinate (X − 38 Y + 44 Z + 26) derived from our previous work. We performed nasion-inion, tragus–tragus, and head-circumference measurements on the same subjects’ MRIs, and applied the BeamF3 heuristic. We then compared the distance between BeamF3 and MRI-guided scalp sites. Results: BeamF3-to-MRI-guided discrepancies were <0.65 cm in 50% of subjects, <0.99 cm in 75% of subjects, and <1.36 cm in 95% of subjects. The angle from midline to the scalp site did not differ significantly using MRI-guided versus BeamF3 methods. However, the length of the radial arc from vertex to target site was slightly but significantly longer (mean 0.35 cm) with MRI-guidance versus BeamF3. Conclusions: The BeamF3 heuristic may provide a reasonable approximation to MRI-guided neuronavigation for locating left DLPFC in a majority of subjects. A minor optimization of the heuristic may yield additional concordance.en-USNeuronavigationPrefrontal cortexTranscranial magnetic stimulationMagnetic resonance imagingScalpJournal Article2016-11-1810.1016/j.brs.2015.05.008