RÉSUMÉ
INTRODUCTION: Currently, the diagnosis of salivary gland tumors using imaging techniques is unreliable. METHODS: In this monocentric retrospective study, we examined patients who received a 68Ga-DOTATOC PET/CT and subsequently underwent a salivary gland tumor resection between 1 January 2010 and 31 December 2021. PET/CT image assessment was compared with somatostatin receptor (SSTR) expression and histology. RESULTS: Thirteen patients (five pleomorphic adenoma (PA) and eight other parotid lesions (OPL)) received a 68Ga-DOTATOC PET/CT. Imaging displayed strong focal tracer uptake in all PA except for one with strong tumor to background discrimination. PA revealed higher SUVmax, SUVmean, liver and blood pool quotients than those of Warthin tumors (WT) and of OPL. In comparison to the contralateral parotid, SUVmax (p = 0.02), SUVmean (p = 0.02), liver quotient (p = 0.03) and blood pool quotient (p = 0.03) were all significantly higher. In contrast, WT and OPL showed in relation to the contralateral parotid no significant differences of SUVmax (WT p = 0.79; OPL p = 0.11), SUVmean (WT p = 1.0; OPL p = 0.08), liver quotient (WT p = 0.5; OPL p = 0.08) and blood pool quotient (WT p = 0.8; OPL p = 0.19). Two PA and one granuloma were not available for examination. In the immunohistochemal analysis, all PA demonstrated the highest intensity of SSTR2 expression (grade 3). Furthermore, PA had a high percentage of cells expressing SSTR2 (20%, 80% and 55%). CONCLUSIONS: A strong tracer uptake in PA was shown in 68Ga-DOTATOC PET/CT. This may allow physicians to utilize radioligated somatostatin analogue PET CT/MR imaging to accurately diagnose PA. Additionally, it may be possible in the future to treat the PA with a noninvasive peptide receptor radionuclide therapy or with somatostatin analogues.
RÉSUMÉ
Locally-advanced head and neck squamous cell carcinoma (HNSCC) is mainly defined by the presence of pathologic cervical lymph nodes (LNs) with or without extracapsular spread (ECS). Current radiologic criteria to classify LNs as non-pathologic, pathologic, or pathologic with ECS are primarily shape-based. However, significantly more quantitative information is contained within imaging modalities. This quantitative information could be exploited for classification of LNs in patients with locally-advanced HNSCC by means of artificial intelligence (AI). Currently, various reviews exploring the role of AI in HNSCC are available. However, reviews specifically addressing the current role of AI to classify LN in HNSCC-patients are sparse. The present work systematically reviews original articles that specifically explore the role of AI to classify LNs in locally-advanced HNSCC applying Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and the Study Quality Assessment Tool of National Institute of Health (NIH). Between 2001 and 2022, out of 69 studies a total of 13 retrospective, mainly monocentric, studies were identified. The majority of the studies included patients with oropharyngeal and oral cavity (9 and 7 of 13 studies, respectively) HNSCC. Histopathologic findings were defined as reference in 9 of 13 studies. Machine learning was applied in 13 studies, 9 of them applying deep learning. The mean number of included patients was 75 (SD ± 72; range 10-258) and of LNs was 340 (SD ± 268; range 21-791). The mean diagnostic accuracy for the training sets was 86% (SD ± 14%; range: 43-99%) and for testing sets 86% (SD ± 5%; range 76-92%). Consequently, all of the identified studies concluded AI to be a potentially promising diagnostic support tool for LN-classification in HNSCC. However, adequately powered, prospective, and randomized control trials are urgently required to further assess AI's role in LN-classification in locally-advanced HNSCC.
RÉSUMÉ
Effective targeted treatment strategies resulted from molecular profiling of lung cancer with distinct prevalent mutation profiles in smokers and non-smokers. Although Rn is the second most important risk factor, data for Rn-dependent driver events are limited. Therefore, a Rn-exposed cohort of lung cancer patients was screened for oncogenic drivers and their survival and genetic profiles were compared with data of the average regional population. Genetic alterations were analysed in 20 Rn-exposed and 22 histologically matched non-Rn exposed LC patients using targeted Next generation sequencing (NGS) and Fluorescence In Situ Hybridization (FISH). Sufficient material and sample quality could be obtained in 14/27 non-exposed versus 17/22 Rn-exposed LC samples. Survival was analysed in comparison to a histologically and stage-matched regional non-exposed lung cancer cohort (n = 51) for hypothesis generating. Median overall survivals were 83.02 months in the Rn-exposed and 38.7 months in the non-exposed lung cancer cohort (p = 0.22). Genetic alterations of both patient cohorts were in high concordance, except for an increase in MET alterations and a decrease in TP53 mutations in the Rn-exposed patients in this small hypothesis generating study.
RÉSUMÉ
In head and neck squamous cell carcinoma (HNSCC) pathologic cervical lymph nodes (LN) remain important negative predictors. Current criteria for LN-classification in contrast-enhanced computed-tomography scans (contrast-CT) are shape-based; contrast-CT imagery allows extraction of additional quantitative data ("features"). The data-driven technique to extract, process, and analyze features from contrast-CTs is termed "radiomics". Extracted features from contrast-CTs at various levels are typically redundant and correlated. Current sets of features for LN-classification are too complex for clinical application. Effective eliminative feature selection (EFS) is a crucial preprocessing step to reduce the complexity of sets identified. We aimed at exploring EFS-algorithms for their potential to identify sets of features, which were as small as feasible and yet retained as much accuracy as possible for LN-classification. In this retrospective cohort-study, which adhered to the STROBE guidelines, in total 252 LNs were classified as "non-pathologic" (n = 70), "pathologic" (n = 182) or "pathologic with extracapsular spread" (n = 52) by two experienced head-and-neck radiologists based on established criteria which served as a reference. The combination of sparse discriminant analysis and genetic optimization retained up to 90% of the classification accuracy with only 10% of the original numbers of features. From a clinical perspective, the selected features appeared plausible and potentially capable of correctly classifying LNs. Both the identified EFS-algorithm and the identified features need further exploration to assess their potential to prospectively classify LNs in HNSCC.