FDG avidity at PET/CT during adjuvant hormonal therapy in patients with breast cancer.

BACKGROUND: We aim to retrospectively evaluate the impact of hormone therapy (HT) on FDG avidity of metastatic lesions in patients with breast cancer (BC) undergoing PET/CT. PATIENTS AND METHODS: Three hundred eight patients with BC were scanned with PET/CT at 2 Italian institutions (mean time from diagnosis 4 yrs, range: 1-24 yrs). Main indications for PET/CT were elevation of tumor markers (34.4%) and clinical or radiological suspicion of relapse (65.6%). The diagnostic accuracy of FDG PET/CT was computed according to the standard method. Student t test was used to assess the mean differences between the study groups, whereas categorical data were compared with chi-square test. Significance was set at P <0.05. RESULTS: Two hundred sixty-four patients with positive estrogen receptor and who had received adjuvant HT were included in the analysis. At the time of PET/CT scan, HT was ongoing in 176 patients (66.7%) and 88 (33.3%) had completed adjuvant HT. Ninety-eight (55.7%) patients on HT and 59 (67%) off HT had a positive PET/CT; therefore, the scan resulted negative in the remaining 107 patients, 78 and 29 on and off HT, 44.3% and 33%, respectively (P < 0.001). At a median follow-up of 7 months (range 1-48 mos), disease recurrence was confirmed in either clinical or radiological examinations in 126 (47.7%) patients; 72 (40.9%) versus 54 (61.4%) patients on and off HT, respectively (P < 0.005). True-positive PET/CT results were found in 82% and 91% of patients on and off HT, respectively, whereas it failed to identify disease relapse in 13 (18%) and 5 (9%) patients on and off HT, respectively. CONCLUSIONS: In our series, FDG PET/CT shows a similar diagnostic accuracy in detecting disease relapse between patients with BC on adjuvant HT versus those who have completed therapy. These preliminary results suggest that the glucose metabolism is not altered by hormonal suppression at the time of the scan.

Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer.

PURPOSE: The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer. METHODS: Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data. RESULTS: SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p = 0.004 and p = 0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate. CONCLUSION: The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate.

99mTc-HMPAO-leukocyte scintigraphy in patients with symptomatic total hip or knee arthroplasty: improved diagnostic accuracy by means of semiquantitative evaluation.

UNLABELLED: The aim of this study was to evaluate the diagnostic value, in suspected infectious prostheses, of (99m)Tc-labeled hexamethylpropyleneamine oxime ((99m)Tc-HMPAO) leukocyte scintigraphy interpreted with the addition of a semiquantitative analysis. METHODS: By means of a retrospective review, we included a group of 78 consecutive patients with suspected hip or knee prosthesis infection. We performed 91 (99m)Tc-HMPAO-leukocyte scintigraphies and examined 95 localizations that were suspect. Images were acquired at 3 different time points after the injection of the labeled leukocytes: 50 min (early images), 4 h, and 24 h (late images). The scintigraphic examinations were independently evaluated by 3 observers; qualitative and semiquantitative analyses were performed. The final diagnosis of infection was based on surgical, histologic, and bacteriologic data and follow-up. RESULTS: On qualitative analysis, sensitivity, specificity, and accuracy were 80.4%-87%, 65.3%-71.4%, and 75.8%-77.9%, respectively. On semiquantitative analysis, sensitivity, specificity, and accuracy were 95.6%, 95.8%, and 95.8%, respectively. The analysis of 95% confidential intervals showed statistically significant differences in specificity and accuracy between semiquantitative and qualitative analyses. CONCLUSION: In those patients who underwent (99m)Tc-HMPAO-leukocyte scintigraphy for suspected hip or knee prosthesis infection, the addition of a semiquantitative evaluation to the qualitative analysis of early and late images leads to a significant improvement in both specificity and accuracy.