A sheet pocket to prevent cross-contamination of formalin-fixed paraffin-embedded block for application in next generation sequencing.

Formalin-fixed paraffin-embedded (FFPE) blocks are used as biomaterials for next-generation sequencing of cancer panels. Cross-contamination is detected in approximately 5% of the DNA extracted from FFPE samples, which reduces the detection rate of genetic abnormalities. There are no effective methods available for processing FFPE blocks that prevent cells from mixing with other specimens. The present study evaluated 897 sheets that could potentially prevent cell transmission but allow for the movement of various solvents used in FFPE blocks. According to the International Organization for Standardization and Japanese Industrial Standards, six requirements were established for the screening of packing sheets: 1) filter opening ≤5 µm, 2) thickness ≤100 µm, 3) chemical resistance, 4) permeability ≥1.0 × 10-3 cm/s, 5) water retention rate <200%, and 6) cell transit test (≤2 cells/10 high-power fields). Polyamide, polyethylene terephthalate, and polypropylene/polyethylene composite sheets met all criteria. A pocket, which was designed to wrap the tissue uniformly, was made of these sheets and was found to effectively block the entry of all cell types during FFPE block processing. Using a sheet pocket, no single cell from the cell pellet could pass through the outer layer. The presence or absence of the sheet pocket did not affect hematoxylin and eosin staining. When processing FFPE blocks as a biomaterial for next-generation sequencing, the sheet pocket was effective in preventing cross-contamination. This technology will in part support the precise translation of histopathological data into genome sequencing data in general pathology laboratories.

Clinical Study of Sentinel Lymph Node Detection Using Photodynamic Eye for Abdominal Radical Trachelectomy.

This study aimed to assess the accuracy of predicting pelvic lymph node status using sentinel lymph node (SLN) biopsy with indocyanine green (ICG) and to examine the outcomes of SLN biopsy-guided abdominal radical trachelectomy (ART). Patients with stage IA2-IB2 cervical cancer from January 2009 to January 2021 were included. ICG was injected before ART and SLNs were identified, excised, and assessed intraoperatively using fast-frozen sections. Systemic pelvic lymphadenectomy was subsequently performed. The SLN detection rate, sensitivity, and false-negative rate were determined. Thirty patients desiring fertility preservation were enrolled, of whom 26 successfully completed ART and four underwent radical hysterectomies because of metastatic primary SLNs. Bilateral SLNs were identified in all patients. The sensitivity, false-negative rate, and negative predictive value were 100%, 7.7%, and 92.3%, respectively. Three (12%) patients were lost to follow-up: two relapsed and one died of tumor progression. Of the nine patients who tried to conceive after surgery, four achieved pregnancy and three delivered healthy live infants. In women with early-stage cervical cancer who desired to conserve fertility, SLN mapping with ICG had a very high detection rate, sensitivity, and low false-negative rate. SLN biopsy-guided ART is a feasible and accurate method for assessing pelvic node status.