F-18 FDG PET Findings in a Port Site Recurrence After Laparoscopic Radical Nephrectomy in a Patient With Renal Cell Carcinoma

Local recurrence of renal cell carcinoma after partial nephrectomy: applicability of the apparent diffusion coefficient of MRI as an imaging marker - a multicentre study

Purpose

The goal of the study was an assessment of the diagnostic performance of diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) of magnetic resonance imaging (MRI) in distinguishing local recurrence (LR) of renal cell carcinoma (RCC) from benign conditions after partial nephrectomy.

Material and methods

Thirty-nine patients after partial nephrectomy for solid RCC were enrolled in the study. Patients were followed up using MRI, which included DWI sequence (b = 800 s/mm²). All patients with MRI features of LR were included in the main group (n = 14) and patients without such features – into the group of comparison (n = 25). Apparent diffusion coefficient (ADC) values of suspicious lesions were recorded. In all patients with signs of locally recurrent RCC, surgical treatment was performed followed by pathologic analysis.

Results

The mean ADC values of recurrent RCC demonstrated significantly higher numbers compared to benign fibrous tissues and were 1.64 ± 0.15 × 10^-3 mm²/s vs. 1.02 ± 0.26 × 10^-3 mm²/s (p < 0.001). The mean ADC values of RCCs’ LR and benign post-op changes in renal scar substantially differed from mean ADC values of healthy kidneys’ parenchyma; the latter was 2.58 ± 0.05 × 10^-3 mm²/s (p < 0.001). In ROC analysis, the use of ADC with a threshold value of 1.28 × 10^-3 mm²/s allowed us to differentiate local recurrence of RCC from benign postoperative changes with 100% sensitivity, 80% specificity, and accuracy: AUC = 0.980 (p < 0.001).

Conclusions

The apparent diffusion coefficient of DWI of MRI can be used as a potential imaging marker for the diagnosis of local recurrence of RCC.

Port-site metastasis after laparoscopic removal of an isolated adrenal metastasis in a patient with breast cancer detected with FDG PET/CT

Adrenal metastasis from breast cancer rarely occurs in the course of this disease. Laparoscopic surgery has increased in the therapy for malignant tumors because of its lower morbidity and mortality compared with conventional surgical methods. However, complications such as the appearance of a port-site metastasis may also occur. Clinical examination and conventional cross-sectional imaging usually reveal this only at advanced stage. The authors reported on a case with abdominal wall port-site metastasis detected with F-FDG PET/CT 33 months after the laparoscopic removal of a late-onset, PET/CT-verified adrenal metastasis from lobular breast cancer.