# Performance of image-guided bone biopsies in malignant lesions: impact of PET/CT metabolic activity on the number of samples required

## TL;DR

This study found that high metabolic activity in tumors on PET/CT scans does not reduce the number of biopsy samples needed for a diagnosis, suggesting at least three samples should always be taken.

## Contribution

The study provides new evidence that PET/CT metabolic parameters do not reliably predict the number of biopsy samples required for a diagnosis in image-guided bone biopsies.

## Key findings

- High metabolic activity on PET/CT does not justify reducing the number of biopsy samples needed for diagnosis.
- No significant differences in metabolic parameters were found between groups requiring different numbers of biopsy samples.
- At least three biopsy samples are recommended regardless of metabolic activity to ensure diagnostic accuracy.

## Abstract

The purpose of the present study is to determine whether or not lesion characteristics on PET/CT could reduce the number of samples required to achieve a diagnosis in image-guided bone biopsies (IGBB).

A retrospective review of 38 percutaneous IGBB performed at a single center. Biopsies have been performed from January 1st, 2020, to October 23rd, 2024. Inclusion criteria were patients with a PET/CT and a histopathologic report available. Specimens were collected, numbered, and independently analyzed in separate containers. PET/CT data, including SUVmax, SUVmean, MTV, TLG, and morphological lesion characteristics, were correlated with biopsy outcomes and subjected to statistical analysis. Patients were classified by the number of samples needed for diagnosis: first (Group 1), second (Group 2), or third/subsequent (Group 3).

Thirty-four/38 (89%) involved spinal and pelvic locations (34/38; 89%). Breast cancer metastases were the most common diagnosis (21/38; 55%). Group 1 included 20 IGBB (52%), group 2 included 9 IGBB (24%), and group 3 included 9 IGBB (24%). No statistically significant difference was found between groups in metabolic characteristics and the number of samples needed for diagnostic purposes (p > 0.05). Subgroup analysis, including factors such as density or lesion size, didn’t find any significant differences between groups.

The results suggest that high metabolic activity alone does not justify reducing the number of biopsy samples without compromising diagnostic performance. This supports the recommendation to obtain at least three samples and highlights the importance of selecting the safest biopsy site, regardless of metabolic activity.

This study critically assesses the role of FDG PET/CT metabolic parameters in predicting the diagnostic success of IGBB, providing new insights to improve target selection and biopsy planning in clinical radiology.

This study assessed whether metabolic activity on FDG PET/CT influences the diagnostic yield of IGBB.High metabolic activity did not allow for reducing the number of samples without affecting diagnostic performance.At least three biopsy samples should be obtained, prioritizing safety over metabolic activity when selecting the biopsy site.

This study assessed whether metabolic activity on FDG PET/CT influences the diagnostic yield of IGBB.

High metabolic activity did not allow for reducing the number of samples without affecting diagnostic performance.

At least three biopsy samples should be obtained, prioritizing safety over metabolic activity when selecting the biopsy site.