Accuracy and clinical utility of the compact micro-robot: a retrospective study of 95 cases

Robotic platforms for stereotactic neurosurgery have evolved rapidly, but compact systems have not been clinically validated in large cohorts.

To assess targeting accuracy and safety of the compact micro-robot (Q300, 1.5 kg, three-dimensional structured-light registration) across multiple stereotactic procedures, and to contextualize its performance against published data from established platforms.

We retrospectively analyzed 95 consecutive patients who underwent Q300-guided neurosurgery at Beijing Tiantan Hospital (October 2022-August 2024). Procedures included brain biopsy (n=57), ventriculoperitoneal shunt (n=17), CSF bypass procedures (n=17), and catheter drainage (n=4). The primary outcome was targeting error (TE), defined as the Euclidean distance between planned and actual target points on fused postoperative CT. Entry error (EE) was defined as the Euclidean distance between planned and actual entry points on the skull surface. Secondary outcomes included diagnostic yield, complication rate, and operative time.

The mean EE was 0.92 ± 0.47 mm (median 0.85, IQR 0.55-1.20), and the mean TE was 0.95 ± 0.56 mm (median 0.88, IQR 0.56-1.22). All 57 biopsies yielded conclusive histopathological diagnosis (100% diagnostic tissue acquisition rate). The complication rate was 6.3% (6/95), including 3 hemorrhages managed conservatively and 3 infections after temporal horn bypass. No mortality or permanent neurological deficit occurred. The mean operative time was 73.8 ± 31.1 min (range 17-240) in 95 procedures.

The compact micro-robot achieved submillimetric median accuracy, 100% diagnostic tissue acquisition, and efficient operative times across 95 procedures. Its lightweight design and rapid registration offer practical workflow advantages. The infection rate in temporal horn bypass (3/10) requires further investigation.