CT guided percutaneous needle biopsy of the chest: initial experience

The objective of this article is to report our first experience of CT guided percutaneous thoracic biopsy and to demonstrate the accuracy and safety of this procedure. This was a retrospective study of 28 CT-Guided Percutaneous Needle Biopsies of the Chest performed on 24 patients between November 2014 and April 2015. Diagnosis was achieved in 18 patients (75%), negative results were found in 3 patients (12,5%). Biopsy was repeated in these cases with two positive results. Complications were seen in 7 patients (29%), Hemoptysis in 5 patients (20%), Pneumothorax in 1 patient (4,1%) and vaso-vagal shock in 1 patient (4,1%). CT Guided Percutaneous Needle Biopsy of the Chest is a safe, minimally invasive procedure with high sensitivity, specificity and accuracy for diagnosis of lung lesions.


Introduction
CT Guided Percutaneous Needle Biopsy of the Chest is a minimally invasive procedure frequently indicated for the diagnosis of lung lesions [1]. This technique was first described in 1976 [2] and CT guidance is the primary Imaging modality. Core needle biopsies provide high quality tissue samples for histologic analysis and immunohistochemical testing [3,4]. Complications include pneumothorax, haemorrhage, air embolism and tumor seeding, with pneumothorax being the most frequent [5]. Throughout the world, this technique is useful and accurate in the diagnosis of peripheral masses. Our study demonstrates the accuracy of this technique, confirms its safety with low complication rates, especially with the use of co axial needles.

Methods
24 patients were included to this retrospective study; they were admitted to the Thoracic surgery department between October 2014 and April 2015. These patients underwent lung biopsies with a core needle biopsy device (16G or 18G) under CT guidance (SOMATOM Definition AS plus 128, Siemens Healthcare, Forchheim, Germany).
All patients with peripheral masses suspicious for malignancy and without suspicion of vascular disease were included in this study.
The patients were admitted one day before the procedure to the thoracic surgery department and a coagulation test was done (prothrombin time, activated prothrombin time and platelet count).
One patient was on oral anticoagulants for atrial fibrillation (Coumadine*), the treatment was replaced with heparin 5 days before the procedure [6]. We informed patients about the benefits and risks of the procedure such as pneumothorax and haemorrhage and consent was obtained. A peripheral IV cannula was placed before installing patient in the CT scanner. All biopsies were done under CT guidance. The patient was positioned prone, supine or in lateral decubitus, according to the location of the lesion. The lesion was localised and the access route was planned using our Chest intervention protocol including a first 2 mm slice thickness acquisition used to localise the lesion, then the entry site was marked by a permanent marker, and distance between the skin surface and the lesion was measured. Then, the skin entry site and

Discussion
In our retrospective study on CT Guided Percutaneous Needle Biopsy, diagnostic accuracy rate was 75%. Non diagnostic biopsy rate was 12,5%. Complications were essentially alveolar hemorrhage (20, 8%) and pneumothorax (4,2%) in a smaller proportion. Spontaneous reabsorption of alveolar hemorrhage and pneumothorax was seen in all patients with no need to proceed to other interventions such as chest drain insertion. Percutaneous CTguided core needle biopsy is a safe procedure with a high accuracy for diagnosis of lung malignancies [7]. Our results confirm that CT Guided Percutaneous Lung Biopsy is a safe procedure allowing diagnosis of lung lesions in the majority of patients. Major complications were pneumothorax and hemorrhage with good outcomes and spontaneous reabsorption. The presence of emphysema was challenging, meaning a greater risk of pneumothorax, most common in our smoking patient population [8]. Deeper lesions require traversing a greater amount of lung parenchyma and increase the risk of pneumothorax and hemorrhage; we did not notice any of those incidents in our study.
We thought that small anterior and lateral lesions were highly challenging to reach because of respiratory motion; so good communication with the patient and soft respiration were mandatory to successfully achieve the procedure with few or no complications. Limitations of our study were the small number of patients included and the retrospective design.

Conclusion
In conclusion, CT-guided percutaneous needle biopsy is a safe procedure with a high diagnostic accuracy rate in the diagnosis of malignant lung lesions.
What is known about this topic  Percutaneous thoracic CT guided biopsy is an accurate procedure for diagnosis of lung malignancies;  Major complications are pneumothorax and alveolar hemorrhage;  CT is a very helpful tool to localize the lesion and achieve the procedure.

What this study adds
 Percutaneous thoracic CT guided biopsy with 18 G co axial needle is a very safe procedure with lesser complication rate;  CT protocol used in this study limits the radiation exposure of patients;  The procedure can also be achieved in emphysematous patients without increasing complication rate.