Role of 18F-Choline Positron Emission Tomography/Computed Tomography to Detect Structural Relapse in High-Risk Differentiated Thyroid Cancer Patients.

BACKGROUND: This study aimed to evaluate the role of 18F-choline (18F-FCH) positron emission tomography (PET)/computed tomography (CT) in high-risk differentiated thyroid cancer (DTC) patients with suspected relapse. It also compared 18F-FCH-PET/CT results with those of fludeoxyglucose (18F-FDG)-PET/CT and evaluated the additional diagnostic value and clinical impact of the combined use of these two tracers. Finally, it assessed the association between the clinical, biochemical, and histological parameters and 18F-FCH-PET/CT and 18F-FDG-PET/CT results. METHODS: The study prospectively enrolled high-risk DTC patients treated with thyroidectomy and radioactive iodine therapy and presenting high/increasing thyroglobulin levels under thyrotropin suppression, negative/inconclusive neck ultrasound, and negative 131I whole-body scan. All patients underwent 18F-FDG-PET/CT and 18F-FCH-PET/CT within 30 days of each other. Experienced nuclear medicine physicians examined the images of both procedures, and an integrated analysis of the two PET/CT modalities was also conducted. For each modality, a patient-based analysis (PBA) and lesion-based-analysis (LBA) was performed. On PBA, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated. On LBA, only sensitivity was calculated. The standard of reference was based on clinical, imaging, and histological data. RESULTS: Twenty-five high-risk DTC patients were included; DTC relapse/persistence was confirmed in 23 patients. On PBA, 18F-FDG-PET/CT, 18F-FCH-PET/CT, and the integrated evaluation of the two imaging modalities showed the following rates: sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 69.6%, 100%, 22.2%, 100%, and 72% versus 56.5%, 100%, 16.7%, 100%, and 60% versus 82.6%, 100%, 33.3%, 100%, and 84%, respectively. When compared with 18F-FDG-PET/CT, the integrated analysis of these two imaging procedures changed the clinical management in 4/23 (17%) patients. On LBA, the sensitivity rates of 18F-FDG-PET/CT, 18F-FCH-PET/CT, and the combined evaluation of the two modalities were 58.7%, 38.1%, and 66.7%, respectively; when only lymph node involvement was considered, the rates were 56.3%, 53.1%, and 68.8%, respectively. Serum thyroglobulin doubling time (Tg-DT) <12 months was significantly associated with positive 18F-FCH-PET/CT. A trend toward a significant association was also found between positive 18F-FDG-PET/CT and both Tg-DT <12 months and DTC aggressive subtypes. CONCLUSION: 18F-FCH-PET/CT may add important information during the follow-up of high-risk DTC patients. 18F-FCH-PET/CT may be considered a useful complementary tool in patients affected by non-aggressive DTC subtypes, with Tg-DT <12 months, high risk of lymph node spreading, and negative or doubtful 18F-FDG-PET/CT.

Synergy of cytological methods in the pathological staging of breast cancer: Axillary fine-needle aspiration and intraoperative scrape cytology of the sentinel lymph node.

BACKGROUND: Sentinel lymph node biopsy (SLNB) has become the standard in breast cancer staging, but it is costly and time-consuming. Fine-needle aspiration cytology (FNAC) under ultrasonographic guidance identifies patients who need axillary lymph-node dissection (ALND), thus reducing costs. As an alternative to frozen sections (FS), intraoperative scrape cytology (ISC) for SLNB is an inexpensive, rapid, accurate and safe technique. We evaluated the synergy of FNAC and SLNB in determining the axillary burden and the performance of the ISC method. METHODS: Over a nine-year period, 894 breast cancer patients were analyzed. Of these, 439 patients with echographic suspicious nodes underwent preoperative FNAC; negative axillary ultrasounds or FNACs resulted in 606 intraoperative SLNB, performed using the ISC technique. The results were compared with histological diagnosis, and sensitivity, specificity, predictive values and accuracy were calculated. RESULTS: Of the 439 FNACs, 121 were positive and underwent immediate ALND, and 242 negative patients underwent intraoperative SLNB (69% sensitivity, 99% specificity). Positive cases often had multiple nodal involvement (55% pN2-3). Of the 606 SLNB-ISC smears, 510 were true negative; 65 true positives allowed for one-step ALND (71% sensitivity, 99% specificity). CONCLUSION: Preoperative positive axillary FNAC predicts a higher disease burden and determines the avoidance of SLNB for patients eligible for immediate ALND. ISC instead of FS is a safe and sensitive technique to identify metastases, indicating completion of ALND. PARTIALLY PRESENTED AT: Joint International Oncology (sentinel node & cancer metastasis) Congress, May 27-29, 2013, San Francisco, California, USA 18 ° International Congress of Cytology (ICC 2013-1161), May 26-30, 2013, Paris, France Convegno Nazionale GISMa - Finalborgo (Savona), Italy,19-20 maggio 2016.

Immunohistochemistry on old archival paraffin blocks: is there an expiry date?

Few studies have focused on antigen preservation in formalin-fixed and paraffin-embedded (FFPE) tissue in old archival material and additional studies are required, especially considering that these samples are an irreplaceable resource for scientific and clinical research. The purpose of this study is to verify antigen preservation in FFPE tissue samples stored for several decades. From the pathology archives, FFPE blocks were selected dating back to the 1960s, 1970s, 1980s, 1990s, 2000s and 2010. A panel of 12 antibodies was applied and immunoreactivities were compared. While cytoplasmic antigens showed no reduction in immunostaining intensity over time, membrane and nuclear antigens presented reduced staining intensity in older blocks. In particular, the nuclear antigen, Ki67 and CD31 showed the most pronounced antigen decay in the oldest archival blocks. In order to test possible antigen recovery, deep sectioning and lengthening of heat pretreatment were applied. Both strategies partially recover antigenicity, but their simultaneous application shows the best results.