Long-Half-Life 89Zr-Labeled Radiotracers Can Guide Percutaneous Biopsy Within the PET/CT Suite Without Reinjection of Radiotracer

Abstract

The rationale for this study was to evaluate the feasibility of within-suite ⁸⁹Zr-labeled radiotracer PET/CT-guided biopsy performed without reinjection. Methods: From 2013 to 2016, 12 patients (7 men, 5 women; mean age, 61 y; range, 40-75 y) with metastatic prostate or breast carcinoma suspected either on imaging or because of biochemical progression underwent 14 percutaneous biopsies after diagnostic PET/CT using ⁸⁹Zr-labeled radiotracers (mean dose, 180 MBq; range, 126-189 MBq) targeting prostate-specific membrane antigen (n = 7) or human epidermal growth factor receptor 2 (n = 5). Biopsy was performed within a PET/CT suite without radiotracer reinjection. Results: There were no complications in any biopsies, which were performed a mean of 6.2 d (range, 0-13 d) after injection of the radiotracer. The biopsy sites were bone (n = 7), pleura (n = 3), lymph nodes (n = 2), and liver (n = 2). On pathologic examination of the biopsy samples, all were positive for malignancy. The initial diagnostic imaging findings were concordant with the biopsy results. The additional radiation (mean dose-length product) due to the CT procedures was 1,581 mGy/cm (range, 379-2,686 mGy/cm). Conclusion: PET/CT-guided biopsy using ⁸⁹Zr-labeled radiotracers is safe and effective without tracer reinjection.

Keywords: 89Zr; PET/CT; biopsy; interventional radiology; metastasis.

FIGURE 1.

Delayed PET/CT-guided biopsy of bone metastasis from prostate carcinoma in 64-y-old man with strongly suspected metastatic prostate carcinoma (prostatic-specific antigen level, 91 ng/mL), without history of bone radiotherapy. (A) Axial CT scan shows suggestive increase in density (dashed arrow) on iliac bones. (B) Axial ⁸⁹Zr anti-PSMA–targeted PET/CT image shows new lesions on right iliac wing and sacrum (solid arrow). Interestingly, lesion identified on CT shows no uptake on PET (arrowhead). (C) Axial ⁸⁹Zr anti-PSMA–targeted PET/CT image 7 d after injection shows lesions, including the one that was biopsied. Pathologic examination confirmed metastasis from prostate carcinoma.

FIGURE 2.

Delayed PET/CT-guided biopsy of bone and lung metastases in 51-y-old woman with breast carcinoma. (A and B) Axial contrast-enhanced CT scans show bone lesions in left iliac wing (arrowhead) and sacrum (solid arrow), as well as a thoracic mass (dashed arrow). (C and D) Axial ⁸⁹Zr antiHER2–targeted PET/CT images show metastases in left iliac crest (arrow) and lung but no lesion in sacrum. (E and F) Corresponding images from within-suite PET/CT biopsy 2 d after injection show residual uptake. Pathologic examination confirmed metastasis from breast carcinoma.

FIGURE 3.

Delayed PET/CT-guided biopsy of lymph node metastasis from prostate carcinoma in 75-y-old man with strongly suspected metastatic prostate carcinoma (prostatic-specific antigen level, 10 ng/mL). (A) Axial CT scan shows 15-mm right iliac lymph node (dashed arrow). (B) Axial ⁸⁹Zr anti-PSMA–targeted PET/CT image shows lymph node (arrow). (C) Corresponding images from within-suite PET/CT biopsy 6 d after injection show residual uptake. Pathologic examination confirmed metastasis from prostate carcinoma.