Novel navigation surgery using image fusion of PET/CT and sonography for axillary neoplasm: First experience

Ultrasound sonography (US)-guided navigation systems are widely used in various organs, including the breast and liver, to locate precisely lesions that are difficult to palpate or isolate after being identified by other imaging techniques. A recent new method, "volume navigation" (Vnav), delivers real-time image fusion of US with other modalities such as MRI, CT, and PET/CT to facilitate identification and excision of suspected pathology.

The present report describes a novel navigation technique using Vnav-PET/CT, which delivers image fusion of US with PET/CT. To identify the axillary targets using Vnav-PET/CT, we set at least two landmarks then injected 0.2ml viscous blue dye in and around the capsule, which resulted in precise resection. Case 1: A 53-year-old woman with 2 PET/CT-positive lymph nodes in the right axilla underwent easy identification of the targets using the navigation technique followed by lymph node dissection. Among 32 lymph nodes dissected, only the two lymph nodes stained by blue dye were shown histologically to be malignant. Case 2: A 68-year-old woman had a PET/CT-positive lymph node in the left axilla. Vnav-PET/CT easily identified the target, which was successfully dissected under local anaesthesia.

This navigation and marking using Vnav-PET/CT helped us easily approach the target, resulted in less surgical time, and avoided unsatisfactory axillary complications. These advances of the navigation system enable us to perform precise minimally invasive surgery.

This is the first report of navigation surgery using Vnav-PET/CT, which may assist minimally invasive procedures, especially in the axilla.