@article{VollmerSaraviVollmeretal.2022,
  author    = {Vollmer, Andreas and Saravi, Babak and Vollmer, Michael and Lang, Gernot Michael and Straub, Anton and Brands, Roman C. and K{\"u}bler, Alexander and Gubik, Sebastian and Hartmann, Stefan},
  title     = {Artificial intelligence-based prediction of oroantral communication after tooth extraction utilizing preoperative panoramic radiography},
  series = {Diagnostics},
  volume    = {12},
  journal   = {Diagnostics},
  number    = {6},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics12061406},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-278814},
  year      = {2022},
  abstract  = {Oroantral communication (OAC) is a common complication after tooth extraction of upper molars. Profound preoperative panoramic radiography analysis might potentially help predict OAC following tooth extraction. In this exploratory study, we evaluated n = 300 consecutive cases (100 OAC and 200 controls) and trained five machine learning algorithms (VGG16, InceptionV3, MobileNetV2, EfficientNet, and ResNet50) to predict OAC versus non-OAC (binary classification task) from the input images. Further, four oral and maxillofacial experts evaluated the respective panoramic radiography and determined performance metrics (accuracy, area under the curve (AUC), precision, recall, F1-score, and receiver operating characteristics curve) of all diagnostic approaches. Cohen's kappa was used to evaluate the agreement between expert evaluations. The deep learning algorithms reached high specificity (highest specificity 100\% for InceptionV3) but low sensitivity (highest sensitivity 42.86\% for MobileNetV2). The AUCs from VGG16, InceptionV3, MobileNetV2, EfficientNet, and ResNet50 were 0.53, 0.60, 0.67, 0.51, and 0.56, respectively. Expert 1-4 reached an AUC of 0.550, 0.629, 0.500, and 0.579, respectively. The specificity of the expert evaluations ranged from 51.74\% to 95.02\%, whereas sensitivity ranged from 14.14\% to 59.60\%. Cohen's kappa revealed a poor agreement for the oral and maxillofacial expert evaluations (Cohen's kappa: 0.1285). Overall, present data indicate that OAC cannot be sufficiently predicted from preoperative panoramic radiography. The false-negative rate, i.e., the rate of positive cases (OAC) missed by the deep learning algorithms, ranged from 57.14\% to 95.24\%. Surgeons should not solely rely on panoramic radiography when evaluating the probability of OAC occurrence. Clinical testing of OAC is warranted after each upper-molar tooth extraction.},
  language  = {en}
}
@article{VollmerSaraviBreitenbuecheretal.2023,
  author    = {Vollmer, Andreas and Saravi, Babak and Breitenbuecher, Niko and Mueller-Richter, Urs and Straub, Anton and Šimić, Luka and K{\"u}bler, Alexander and Vollmer, Michael and Gubik, Sebastian and Volland, Julian and Hartmann, Stefan and Brands, Roman C.},
  title     = {Realizing in-house algorithm-driven free fibula flap set up within 24 hours},
  series = {Frontiers in Surgery},
  volume    = {10},
  journal   = {Frontiers in Surgery},
  doi       = {10.3389/fsurg.2023.1321217},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-353945},
  year      = {2023},
  abstract  = {Objective: This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time. Methods: A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure. Results: The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings. Conclusions: The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.},
  language  = {en}
}
@article{VollmerNaglerHoerneretal.2023,
  author    = {Vollmer, Andreas and Nagler, Simon and H{\"o}rner, Marius and Hartmann, Stefan and Brands, Roman C. and Breitenb{\"u}cher, Niko and Straub, Anton and K{\"u}bler, Alexander and Vollmer, Michael and Gubik, Sebastian and Lang, Gernot and Wollborn, Jakob and Saravi, Babak},
  title     = {Performance of artificial intelligence-based algorithms to predict prolonged length of stay after head and neck cancer surgery},
  series = {Heliyon},
  volume    = {9},
  journal   = {Heliyon},
  number    = {11},
  issn      = {2405-8440},
  doi       = {10.1016/j.heliyon.2023.e20752},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350416},
  year      = {2023},
  abstract  = {Background Medical resource management can be improved by assessing the likelihood of prolonged length of stay (LOS) for head and neck cancer surgery patients. The objective of this study was to develop predictive models that could be used to determine whether a patient's LOS after cancer surgery falls within the normal range of the cohort. Methods We conducted a retrospective analysis of a dataset consisting of 300 consecutive patients who underwent head and neck cancer surgery between 2017 and 2022 at a single university medical center. Prolonged LOS was defined as LOS exceeding the 75th percentile of the cohort. Feature importance analysis was performed to evaluate the most important predictors for prolonged LOS. We then constructed 7 machine learning and deep learning algorithms for the prediction modeling of prolonged LOS. Results The algorithms reached accuracy values of 75.40 (radial basis function neural network) to 97.92 (Random Trees) for the training set and 64.90 (multilayer perceptron neural network) to 84.14 (Random Trees) for the testing set. The leading parameters predicting prolonged LOS were operation time, ischemia time, the graft used, the ASA score, the intensive care stay, and the pathological stages. The results revealed that patients who had a higher number of harvested lymph nodes (LN) had a lower probability of recurrence but also a greater LOS. However, patients with prolonged LOS were also at greater risk of recurrence, particularly when fewer (LN) were extracted. Further, LOS was more strongly correlated with the overall number of extracted lymph nodes than with the number of positive lymph nodes or the ratio of positive to overall extracted lymph nodes, indicating that particularly unnecessary lymph node extraction might be associated with prolonged LOS. Conclusions The results emphasize the need for a closer follow-up of patients who experience prolonged LOS. Prospective trials are warranted to validate the present results.},
  language  = {en}
}
@article{StraubStapfFischeretal.2022,
  author    = {Straub, Anton and Stapf, Maximilian and Fischer, Markus and Vollmer, Andreas and Linz, Christian and L{\^a}m, Thi{\^e}n-Tr{\´i} and K{\"u}bler, Alexander and Brands, Roman C. and Scherf-Clavel, Oliver and Hartmann, Stefan},
  title     = {Bone concentration of ampicillin/sulbactam: a pilot study in patients with osteonecrosis of the jaw},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {19},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {22},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph192214917},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297413},
  year      = {2022},
  abstract  = {Osteonecrosis of the jaw (ONJ) occurs typically after irradiation of the head and neck area or after the intake of antiresorptive agents. Both interventions can lead to compromised bone perfusion and can ultimately result in infection and necrosis. Treatment usually consists of surgical necrosectomy and prolonged antibiotic therapy, usually through beta-lactams such as ampicillin/sulbactam. The poor blood supply in particular raises the question as to whether this form of antibiosis can achieve sufficient concentrations in the bone. Therefore, we investigated the antibiotic concentration in plasma and bone samples in a prospective study. Bone samples were collected from the necrosis core and in the vital surrounding bone. The measured concentrations in plasma for ampicillin and sulbactam were 126.3 ± 77.6 and 60.2 ± 35.0 µg/mL, respectively. In vital bone and necrotic bone samples, the ampicillin/sulbactam concentrations were 6.3 ± 7.8/1.8 ± 2.0 µg/g and 4.9 ± 7.0/1.7 ± 1.7 µg/g, respectively. These concentrations are substantially lower than described in the literature. However, the concentration seems sufficient to kill most bacteria, such as Streptococci and Staphylococci, which are mostly present in the biofilm of ONJ. We, therefore, conclude that intravenous administration of ampicillin/sulbactam remains a valuable treatment in the therapy of ONJ. Nevertheless, increasing resistance of Escherichia coli towards beta-lactam antibiotics have been reported and should be considered.},
  language  = {en}
}
@article{LinzBrandsKertelsetal.2021,
  author    = {Linz, Christian and Brands, Roman C. and Kertels, Olivia and Dierks, Alexander and Brumberg, Joachim and Gerhard-Hartmann, Elena and Hartmann, Stefan and Schirbel, Andreas and Serfling, Sebastian and Zhi, Yingjun and Buck, Andreas K. and K{\"u}bler, Alexander and Hohm, Julian and Lapa, Constantin and Kircher, Malte},
  title     = {Targeting fibroblast activation protein in newly diagnosed squamous cell carcinoma of the oral cavity - initial experience and comparison to [\(^{18}\)F]FDG PET/CT and MRI},
  series = {European Journal of Nuclear Medicine and Molecular Imaging},
  volume    = {48},
  journal   = {European Journal of Nuclear Medicine and Molecular Imaging},
  number    = {12},
  issn      = {1619-7070},
  doi       = {10.1007/s00259-021-05422-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-307246},
  pages     = {3951-3960},
  year      = {2021},
  abstract  = {Purpose While [\(^{18}\)F]-fluorodeoxyglucose ([\(^{18}\)F]FDG) is the standard for positron emission tomography/computed tomography (PET/CT) imaging of oral squamous cell carcinoma (OSCC), diagnostic specificity is hampered by uptake in inflammatory cells such as neutrophils or macrophages. Recently, molecular imaging probes targeting fibroblast activation protein α (FAP), which is overexpressed in a variety of cancer-associated fibroblasts, have become available and might constitute a feasible alternative to FDG PET/CT. Methods Ten consecutive, treatment-na{\"i}ve patients (8 males, 2 females; mean age, 62 ± 9 years) with biopsy-proven OSCC underwent both whole-body [\(^{18}\)F]FDG and [\(^{68}\)Ga]FAPI-04 (FAP-directed) PET/CT for primary staging prior to tumor resection and cervical lymph node dissection. Detection of the primary tumor, as well as the presence and number of lymph node and distant metastases was analysed. Intensity of tracer accumulation was assessed by means of maximum (SUV\(_{max}\)) and peak (SUV\(_{peak}\) standardized uptake values. Histological work-up including immunohistochemical staining for FAP served as standard of reference. Results [\(^{18}\)F]FDG and FAP-directed PET/CT detected all primary tumors with a SUVmax of 25.5 ± 13.2 (FDG) and 20.5 ± 6.4 (FAP-directed) and a SUVpeak of 16.1 ± 10.3 ([\(^{18}\)F]FDG) and 13.8 ± 3.9 (FAP-directed), respectively. Regarding cervical lymph node metastases, FAP-directed PET/CT demonstrated comparable sensitivity (81.3\% vs. 87.5\%; P = 0.32) and specificity (93.3\% vs. 81.3\%; P = 0.16) to [\(^{18}\)F]FDG PET/CT. FAP expression on the cell surface of cancer-associated fibroblasts in both primary lesions as well as lymph nodes metastases was confirmed in all samples. Conclusion FAP-directed PET/CT in OSCC seems feasible. Future research to investigate its potential to improve patient staging is highly warranted.},
  language  = {en}
}