making adjustments to redirect and con rm “tool-in-lesion” prior to biopsy procedures, it is hard to classify this technique under navigation systems but better to consider as a static and refreshable map. Cone beam tomography can be performed by itself or with adjunct navigation systems in peripheral bronchoscopy. Its combination with thin and ultrathin bronchoscopy has a diagnostic yield of 70% [56].

In summary, traditional or novel navigational bronchoscopy-guided procedures generally have a yield of 66–79% (range: 33–96%). There is a gap of high-quality evidence regarding the diagnostic performance of these systems in pulmonary medicine and thoracic oncology [46, 51, 55]. Besides obtaining a diagnosis, precise navigation and localization of a parenchymal lung lesion has an impact on the treatment of the lesion by enabling dye marking for thoracic surgery,ducial placement for stereotactic body radiation therapy, and marking for bronchoscopic ablative therapies that are currently being studied [55].

Image-Guided Transthoracic Needle

Biopsy

Transthoracic needle biopsy is generally used to diagnose peripherally located lung lesions, usually nodules or masses. It can be performed CT-guided, fuoroscopy-guided or US-guided.

CT-Guided Transthoracic Biopsy

The details of anatomic location, margins, shape and attenuation of the lesion, invasion of the chest wall, presence of mediastinal, hilar and segmental lymph nodes, and distance to surrounding structures can be provided by CT. The pooled sensitivity (82–99%) and speci city (94–100%) of transthoracic CT-guided FNA are comparable to those of transthoracic CT-guided CNB. The diagnostic performances of both needle methods are higher in malignancy -particularly lung cancer- than in benign diseases. Although they have high diagnostic performances, their complication risks are high: 18.8% and 25.3% risks of pneumothorax with transthoracic CTguided FNA and CT-guided CNB, respectively, and a 5–15%

risk of bleeding (major hemorrhage: 1%) with both methods. Emphysema, smaller lesion, deeper needle penetration, and multiple passes of needle are the risk factors for complications during transthoracic needle biopsy [2, 3, 57, 58].

Fluoroscopy-Guided Transthoracic Biopsies

Unior bi-planar fuoroscopy -the rst technique used to guide transthoracic FNA and CNBis widely available, familiar to most operators and provides real-time control of the procedure. The sensitivities (72–98%) and speci cities (93– 100%) of fuoroscopy-guided transthoracic FNA and CNB are high and comparable in malignancy, particularly in lung cancer. However, they also have high complication rates. Most frequent complication is pneumothorax (11–28%) [3, 59, 60], and more than half of the pneumothoraces may require chest tube drainage [3, 59].

US-Guided Transthoracic Biopsy

As a safe procedure with a low risk of complications and cost-effective alternative to CT-guided transthoracic biopsy, US-guided transthoracic biopsy is preferred especially if the alternative is diagnostic surgery. In many centers, the procedure is integrated into the overall invasive program performed by pulmonologists. US-guided transthoracic needle biopsy has an acceptable sensitivity (62–95%) and speci city (95–100%) in lung cancer. The complication rate (2.5% pneumothorax, 0.5% hemoptysis) is generally lower than that for CT-guided transthoracic biopsies, and chest tube placement is required in only about 50% of pneumothoraces. US-guided ­transthoracic biopsies should be preferred when a lesion can be visualized by US. However, a central lesion in the lungs or a lesion peripheral but not next to visceral pleura, can not be visualized by ultrasound owing to the refection of ultrasound waves in air between the lesion and visceral pleura [3, 58].

Compared with transthoracic FNA, transthoracic CNB has similar sensitivity for malignancy (86–98% and 92–98%, respectively) whether CT, fuoroscopy or US guidance is used. However, transthoracic CNB has a signi cantly higher performance in determining a speci c diagnosis for