Sentinel lymph node mapping of clinically N0 early oral cancer: a diagnostic pitfall on CT lymphography

CT Lymphography Using Lipiodol® for Sentinel Lymph Node Biopsy in Early-Stage Oral Cancer

This study evaluated sentinel lymph node (SLN) identification with CT lymphography (CTL) following peritumoral administration of Lipiodol^® relative to conventional ^99mTc-nanocolloid lymphoscintigraphy (including SPECT/CT) in 10 early-stage oral cancer patients undergoing SLN biopsy. Patients first underwent early dynamic and static scintigraphy after peritumoral administration of ^99mTc-nanocolloid. Subsequently, Lipiodol^® was administered at the same injection sites, followed by fluoroscopy and CT acquisition. Finally, late scintigraphy and SPECT/CT were conducted, enabling the fusion of late CTL and SPECT imaging. The next day, designated SLNs were harvested, radiographically examined for Lipiodol^® uptake and histopathologically assessed. Corresponding images of CT, ^99mTc-nanocolloid lymphoscintigraphy and SPECT/late CTL fusion were evaluated. ^99mTc-nanocolloid lymphoscintigraphy identified 21 SLNs, of which 7 were identified with CTL (33%). CTL identified no additional SLNs and failed to identify any SLNs in four patients (40%). Out of six histopathologically positive SLNs, two were identified by CTL (33%). Radiographic examination confirmed Lipiodol^® uptake in seven harvested SLNs (24%), of which five were depicted by CTL. CTL using Lipiodol^® reached a sensitivity of 50% and a negative predictive value (NPV) of 75% (median follow-up: 12.3 months). These results suggest that CTL using Lipiodol^® is not a reliable technique for SLN mapping in early-stage oral cancer.

Efficacy of different sentinel lymph node biopsy protocols in oral squamous cell carcinoma: Systematic review and meta-analysis

The sentinel node biopsy (SNB) is highly protocolized in other cancers, however, this is not the case for oral squamous cell carcinoma patients, hence our objective was to evaluate the different protocols published. A specific study protocol was designed and subsequently registered on PROSPERO (Ref. CRD42021279217). Twenty‐three articles were included in the meta‐analysis. The grouped sensitivity of the SNB was 82% (95% CI: 0.74–0.88), and the grouped specificity was 100% (95% CI: 0.99–1.00). The use of other radiotracers other than pre‐operative lopamidol showed higher values of sensitivity of 82.80% (95% CI: 76.90%–87.50%; p < 0.001). The use of the blue dye stain showed higher sensitivity values of 85.60% (95% CI: 71.90%–93.20%), compared to sensitivity values of 77.50% when it was not used (95% CI: 69.10%–84.20%) (p < 0.001). Diagnostic rates are variable and they were significantly better when 99mTc was used in all its variations and accompanied by the blue dye staining.

A Systematic Review of Oral Biopsies, Sample Types, and Detection Techniques Applied in Relation to Oral Cancer Detection

Background: Early identification of the stage of oral cancer development can lead to better treatment outcomes and avoid malignant transformation. Therefore, this review aims to provide a comprehensive overview that describes the development of standardized procedures for oral sample collection, characterization, and molecular risk assessment. This can help investigators to choose the appropriate sampling method and downstream analyses for different purposes. Methods: This systematic review was conducted according to the PRISMA guidelines. Using both PubMed and Web of Science databases, four independent authors conducted a literature search between 15 and 21 June 2021. We used key search terms to broaden the search for studies. Non-conforming articles were removed using an EndNote-based and manual approach. Reviewers used a designed form to extract data. Results: This review included a total of 3574 records, after eliminating duplicate articles and excluding papers that did not meet the inclusion criteria. Finally, 202 articles were included in this review. We summarized the sampling methods, biopsy samples, and downstream analysis. The biopsy techniques were classified into tissue and liquid biopsy. The common sequential analysis of tissue biopsy includes histopathological examination such as H&E or IHC to identify various pathogenic features. Meanwhile, liquid samples such as saliva, blood, and urine are analyzed for the purpose of screening to detect mutations in cancer. Commonly used technologies are PCR, RT-PCR, high-throughput sequencing, and metabolomic analysis. Conclusions: Currently, tissue biopsies provide increased diagnostic value compared to liquid biopsy. However, the minimal invasiveness and convenience of liquid biopsy make it a suitable method for mass screening and eventual clinical adoption. The analysis of samples includes histological and molecular analysis. Metabolite analysis is rising but remains scarce.

Chylous retroperitoneum following 720 degree anteroposterior-combined corrective surgery for adult spinal deformity with split vertebral fracture subluxation: a case report

STUDY DESIGN

Clinical case report.

PURPOSE

To report the rare case with post-operative chylous retroperitoneum after corrective surgery for adult spinal deformity.

METHODS

We present a case of a 73-year-old woman with Parkinson's disease. She sustained a severe split fracture subluxation of the L3 vertebra with AO Spine Thoracolumbar classification type CN2M2, resulting in severe kyphoscoliosis in global alignment. She underwent a two-stage 720-degree anteroposterior-combined corrective surgery with anterior vertebral column resection of L3 and posterior fusion from T4 to the pelvis. On post-operative day 1, milky fluid in the drainage tube was noted, which was diagnosed as post-operative chylous retroperitoneum.

RESULTS

Oral intake was discontinued immediately and peripheral parenteral nutrition was started. A low-fat, high-protein diet was started on post-operative day 4, and drainage was removed on day 6. A low-fat diet was continued until 3 months post-operatively, with dietary counselling by a nutritionist. The chylous retroperitoneum resolved without recurrence at the final follow-up evaluation at 3 years.

CONCLUSION

Surgeons should recognize this rare complication, which might be induced by direct damage to the lymphatic flow during an operative maneuver anterior to the lumbar vertebral body and indirect damage due to shearing force during correction of a subluxated vertebra, especially in cases with a severe deformity.

New Developments in Imaging for Sentinel Lymph Node Biopsy in Early-Stage Oral Cavity Squamous Cell Carcinoma

Sentinel lymph node biopsy (SLNB) is a diagnostic staging procedure that aims to identify the first draining lymph node(s) from the primary tumor, the sentinel lymph nodes (SLN), as their histopathological status reflects the histopathological status of the rest of the nodal basin. The routine SLNB procedure consists of peritumoral injections with a technetium-99m [^99mTc]-labelled radiotracer followed by lymphoscintigraphy and SPECT-CT imaging. Based on these imaging results, the identified SLNs are marked for surgical extirpation and are subjected to histopathological assessment. The routine SLNB procedure has proven to reliably stage the clinically negative neck in early-stage oral squamous cell carcinoma (OSCC). However, an infamous limitation arises in situations where SLNs are located in close vicinity of the tracer injection site. In these cases, the hotspot of the injection site can hide adjacent SLNs and hamper the discrimination between tracer injection site and SLNs (shine-through phenomenon). Therefore, technical developments are needed to bring the diagnostic accuracy of SLNB for early-stage OSCC to a higher level. This review evaluates novel SLNB imaging techniques for early-stage OSCC: MR lymphography, CT lymphography, PET lymphoscintigraphy and contrast-enhanced lymphosonography. Furthermore, their reported diagnostic accuracy is described and their relative merits, disadvantages and potential applications are outlined.

Radiological approach for the newly incorporated T staging factor, depth of invasion (DOI), of the oral tongue cancer in the 8th edition of American Joint Committee on Cancer (AJCC) staging manual: assessment of the necessity for elective neck dissection

The 8^th edition of American Joint Committee on Cancer's (AJCC) Cancer Staging Manual was modified by incorporating depth of invasion (DOI) in the T categorization of oral cavity cancer. This is because DOI is strongly associated with cervical lymph node metastasis, which is the most important negative prognostic factor of oral cavity cancer. This major change in the AJCC Cancer Staging Manual caused re-staging of T category in several cases. Although, the DOI on MRI and CT (radiological DOI; r-DOI) strongly correlated with pathological DOI (p-DOI), it is often 2-3 mm larger than p-DOI. Due to this variance, estimation of p-DOI based on r-DOI may not be accurate. However, when a lesion is undetectable on MRI, p-DOI was often smaller than 4 mm. On the other hand, when MRI depicts lesions with styloglossus and hyoglossus muscle invasion, p-DOI was always larger than 4 mm. These correlations between MRI findings and p-DOI are important when assessing the need for elective neck dissection, as the National Comprehensive Cancer Network (NCCN) recommends elective neck dissection in cases with DOI greater than 4 mm.