CT Guided Biopsies

Success rate of CT guided biopsies.

CT guided biopsies should have a diagnostic yield, appropriate to practice and case mix. The adequacy of the specimen obtained (diagnostic yield) has a direct bearing on patient management. A high success rate instills confidence in the procedure amongst the referring clinicians and patients and may be used to inform consent. Although strictly speaking, the diagnostic accuracy (requiring final surgical diagnosis as the gold standard) is a more precise indicator, diagnostic yield is in effect simpler to measure for audit purposes.

The standard: 

Diagnostic yield varies with technique (FNA vs. cutting biopsy; path chosen), tissue and type of lesion with a range from 70-92% for FNA cytology and 93-100% for histological core biopsy specimens. A locally agreed standard should be used depending on practice and case mix e.g. 80% of CT guided biopsies should have a diagnostic yield [1-9].

Target: 

This will vary according to site/technique of biopsy.

Indicators: 

Percentage of CT guided biopsies which have a diagnostic yield.

Data items to be collected: 

For each biopsy record:

• CT biopsy (radiology) report – including details of the needle used and number of passes

• Cytological and/or histopathological report

• Coded indicator for the operator

Suggested number: 

30 consecutive patients.

• Discuss the results of the audit with the radiologists and pathologists involved

• Introduce a biopsy logbook to encourage follow-up of cases

• Ensure feedback to radiologists from pathologists and clinical colleagues. The MDT may be a useful forum to do this on an up to date case by case basis

• Discuss the need for immediate cytological examination of fine needle aspirates (FNAs) for cellularity

• Use core biopsy where safe and feasible. (FNAC remains technique of choice in the thyroid) Consider multiple passes if difficult.

• If the number of operators is disproportional to the number of cases limit the number of operators to those who achieve the target and maintain adequate CPD. If few operators further training should be considered for individuals not achieving the target

• Computer records to identify patients

• Review radiology reports

• Review pathology reports

• Radiologist (4 hours for reviewing the pathology reports and analysing the data)

1. Husband J E, Golding S J. The role of CT-guided needle biopsy in an oncological service.Clin Radiology 1983;34:255–60.

2. Ferrucci JT et al. Diagnosis of abdominal malignancy by radiologic fine needle biopsy. AJR 1980;134:323–30.

3. Bernardino M E. Percutaneous biopsy. AJR 1984;142:41–5.

4. Labadie M, Liaras A. Percutaneous biopsy: Cytology. In: Dondelinger R. eds. Interventional Radiology New York:Thieme Medical Publishers, 1990.

5. Burbank F et al. Image Guided automated core biopsies of the breast, chest, abdomen and pelvis. Radiology 1994;191:165–71.

6. Moulton, JS, Moore PT. Coaxial percutaneous biopsy technique with automated biopsy devices: value in improving accuracy and negative predictive value. Radiology 1993;186:515.

7. Rubens Chojniak; Rony Klaus Isberner et al. Computed tomography guided needle biopsy: experience from 1,300 procedures. Sao Paulo Med. J. vol.124 no.1 São Paulo Jan./Feb. 2006. www.scielo.br  

8. Gupta S, Krishnamurthy S et al. Small (less than or equal to 2cm) subpleural pulmonary lesions: short- versus long-needle-path CT-guided Biopsy--comparison of diagnostic yields and complications. Radiology. 2005 Feb;234(2):631-7. https://www.ncbi.nlm.nih.gov/pubmed/15673500

9. Laopaiboon V, Aphinives C, Suporntreetriped K. Adequacy and complications of CT-guided percutaneous biopsy: a study of 334 cases in Srinagarind Hospital. J Med Assoc Thai. 2009 Jul;92(7):939-46. http://www.ncbi.nlm.nih.gov/pubmed/19626814

Dr D Remedios