- Gamma Knife radiosurgery
- Gamma Knife radiosurgery for acoustic neuroma
- Gamma Knife radiosurgery for arteriovenous malformations (AVM)
- Gamma Knife radiosurgery for brain metastases
- Gamma Knife radiosurgery for cavernous aginoma
- Gamma Knife radiosurgery for meningiomas
- Gamma Knife radiosurgery for movement disorders
- Gamma Knife radiosurgery for pituitary adenoma
- Gamma Knife radiosurgery for trigeminal neuralgia and other facial pain
- Gamma Knife radiosurgery for uveal melanoma
- Gamma-glutamyl transpeptidase
- Gastric bypass
- Gastroenterological examination
- Gastroesophageal Reflux
- Gastroesophageal surgical examination
- Glycemia
- Glycemic index examination
- Glycosylated hemoglobin
- Gonioscopy
- Gynecological examination
