18F-FDG PET/CT Parameters Enhance MRI Radiomics for Predicting Human Papilloma Virus Status in Oropharyngeal Squamous Cell Carcinoma

PURPOSE

Predicting human papillomavirus (HPV) status is critical in oropharyngeal squamous cell carcinoma (OPSCC) radiomics. In this study, we developed a model for HPV status prediction using magnetic resonance imaging (MRI) radiomics and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) parameters in patients with OPSCC.

MATERIALS AND METHODS

Patients with OPSCC who underwent 18F-FDG PET/CT and contrast-enhanced MRI before treatment between January 2012 and February 2020 were enrolled. Training and test sets (3:2) were randomly selected. 18F-FDG PET/CT parameters and MRI radiomics feature were extracted. We developed three light-gradient boosting machine prediction models using the training set: Model 1, MRI radiomics features; Model 2, 18F-FDG PET/CT parameters; and Model 3, combination of MRI radiomics features and 18F-FDG PET/CT parameters. Area under the receiver operating characteristic curve (AUROC) values were used to analyze the performance of the models in predicting HPV status in the test set.

RESULTS

A total of 126 patients (118 male and 8 female; mean age: 60 years) were included. Of these, 103 patients (81.7%) were HPV-positive, and 23 patients (18.3%) were HPV-negative. AUROC values in the test set were 0.762 [95% confidence interval (CI), 0.564-0.959], 0.638 (95% CI, 0.404-0.871), and 0.823 (95% CI, 0.668-0.978) for Models 1, 2, and 3, respectively. The net reclassification improvement of Model 3, compared with that of Model 1, in the test set was 0.119.

CONCLUSION

When combined with an MRI radiomics model, 18F-FDG PET/CT exhibits incremental value in predicting HPV status in patients with OPSCC.

Development and Testing of a Machine Learning Model Using 18F-Fluorodeoxyglucose PET/CT-Derived Metabolic Parameters to Classify Human Papillomavirus Status in Oropharyngeal Squamous Carcinoma

OBJECTIVE

To develop and test a machine learning model for classifying human papillomavirus (HPV) status of patients with oropharyngeal squamous cell carcinoma (OPSCC) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET-derived parameters in derived parameters and an appropriate combination of machine learning methods in patients with OPSCC.

MATERIALS AND METHODS

This retrospective study enrolled 126 patients (118 male; mean age, 60 years) with newly diagnosed, pathologically confirmed OPSCC, that underwent ¹⁸F-FDG PET-computed tomography (CT) between January 2012 and February 2020. Patients were randomly assigned to training and internal validation sets in a 7:3 ratio. An external test set of 19 patients (16 male; mean age, 65.3 years) was recruited sequentially from two other tertiary hospitals. Model 1 used only PET parameters, Model 2 used only clinical features, and Model 3 used both PET and clinical parameters. Multiple feature transforms, feature selection, oversampling, and training models are all investigated. The external test set was used to test the three models that performed best in the internal validation set. The values for area under the receiver operating characteristic curve (AUC) were compared between models.

RESULTS

In the external test set, ExtraTrees-based Model 3, which uses two PET-derived parameters and three clinical features, with a combination of MinMaxScaler, mutual information selection, and adaptive synthetic sampling approach, showed the best performance (AUC = 0.78; 95% confidence interval, 0.46-1). Model 3 outperformed Model 1 using PET parameters alone (AUC = 0.48, p = 0.047) and Model 2 using clinical parameters alone (AUC = 0.52, p = 0.142) in predicting HPV status.

CONCLUSION

Using oversampling and mutual information selection, an ExtraTree-based HPV status classifier was developed by combining metabolic parameters derived from ¹⁸F-FDG PET/CT and clinical parameters in OPSCC, which exhibited higher performance than the models using either PET or clinical parameters alone.

Characteristics of surgically transposed ovaries on 18F-FDG PET/CT among patients with cancer

OBJECTIVE

Fertility preservation in women with cancer is important for improving their quality of life. Successful ovarian transposition protects the ovary from radiation and preserves ovarian endocrine function and fertility. With the increasing use of ¹⁸F-FDG PET/CT in gynecologic malignancies, the findings of transposed ovaries sometimes vary. This study aimed to characterize the ¹⁸F-FDG PET/CT findings of surgically transposed ovaries among a large number of patients with various medical conditions.

METHODS

We retrospectively reviewed the medical records, including surgical history, and analyzed the findings of the transposed ovaries of patients who underwent ovarian transposition. Quantitative analysis was performed, and the maximum standardized uptake values (SUVs) were recorded. The Hounsfield unit (HU) and size (measured using the long diameter on the axial image) of the transposed ovary were evaluated.

RESULTS

No significant change was found in the SUV of the transposed ovaries in relation to age and time after surgery. In two cases in which metastasis occurred in the transposed ovary, the lesions showed higher SUVs and HUs than did the other non-metastatic transposed ovaries. In several serial follow-up cases, varying ¹⁸F-FDG uptake was observed.

CONCLUSION

The ¹⁸F-FDG uptake pattern of the transposed ovary did not differ from that of the normal ovary. Misinterpretation should be avoided by considering surgical records, presence of surgical clips, and patients' disease state. If there is a high uptake in the transposed ovary, it is necessary to check for soft tissue lesions and differentiate metastasis from the physiologic uptake.

Anti-adhesive effect of a thermosensitive poloxamer applied after the removal of nasal packing in endoscopic sinus surgery: a randomised multicentre clinical trial

OBJECTIVE

To compare the efficacies of a thermosensitive poloxamer (TPX) and Merogel in preventing adhesion applied after the removal of nasal packing in endoscopic sinus surgery as a non-inferiority trial.

DESIGN

Randomised, multicentre, single-blind, active-controlled, matched-pair study.

SETTING

Yonsei University Gangnam Severance Hospital, Korea University Guro Hospital.

PARTICIPANTS

A total of 70 patients were enroled and underwent endoscopic sinus surgeries. Four of the patients did not complete their follow-up. Analysis of the 66 enroled patients having completed postoperative assessment was performed. The severity of rhinosinusitis was graded with a Lund-McKay CT score, and only those with bilateral disease and a CT score difference ≤2 between sinuses were included.

MAIN OUTCOME MEASURES

An independent rhinologist from a third institution through a blinded assessment with digital photoendoscopy of the middle meati bilaterally taken postoperatively.

RESULTS

In the blinded assessment, thermosensitive poloxamer (anti-adhesion rate: 92%) was similar to Merogel (anti-adhesion rate: 89%). Evaluation of the presence and grade of adhesion, oedema, and infection in the middle meatus revealed no significant differences between the thermosensitive poloxamer group and the Merogel group at all postoperative periods.

CONCLUSION

Anti-adhesive effects of thermosensitive poloxamer are similar to those of Merogel. Therefore, thermosensitive poloxamer can be considered a safe alternative to Merogel for preventing adhesion in patients undergoing endoscopic sinus surgeries, and further evaluation of thermosensitive poloxamer as an anti-adhesive and primary packing material compared with the control using no packing is needed.

Fluoroscopy-aided thoracoscopic resection of pulmonary nodule localized with contrast media

BACKGROUND

The pulmonary nodules have become the major indication of video-assisted thoracic surgery (VATS). Recently, several preoperative or intraoperative techniques for identifying small or deeply seated pulmonary nodules have facilitated thoracoscopic resection. We describe the new technique for detecting difficult lesions.

METHODS

Preoperatively, we marked the visceral pleura near the pulmonary nodules with dye, simultaneously injected contrast media (1 water-soluble Optiray [Mallinckrodt Medical Inc, Quebec, Canada], 18 barium sulfate, 11 Lipiodol [Laboratoire Guerbet, Aulnay-sous-Bois, France]) into or around the nodule under computed tomography (CT) guidance. During VATS, we were able to easily and accurately detect and resect all the nodules localized with contrast media, of which the radiopacity was visualized on the portable fluoroscopic monitor.

RESULTS

Between February 1996 and December 1998, we thoracoscopically resected 30 nodules in 28 patients (13 were women; age, 53 +/- 14 years). The resected nodules were 17 +/- 7.6 mm (range; 4 to 32 mm) in size, and 8.9 +/- 8 mm (range, 2 to 34 mm) in depth. The pathologic diagnosis of the nodules was benign in 20 and malignant in 10 (six primary cancers of lung and four metastatic cancers). There were only minor complications related CT localization.

CONCLUSIONS

This new technique can help the surgeons detect and resect the difficult lesions with safety and rapidity by VATS without thoracotomy.

[A photoelastic study of the stress distributions in the surrounding tissues of the abutments of a fixed partial denture with secondary abutments]

The purpose of this study was to evaluate the stress distributions of fixed partial dentures with secondary abutments. In the case where the lower first premolar and the second premolar were missing, four 2-dimensional photoelastic models with the canine and the first molar as primary abutments with secondary abutments were prepared as follows; Model I: primary abutments only. Model II: primary abutments with the lateral incisor as the secondary abutment. Model III: primary abutments with the second molar as the secondary abutment. Model IV: primary abutments with the lateral incisor and the second molar as secondary abutments. Two-dimensional photoelastic stress analysis was used with the stress areas recorded photographically. A vertical load was applied to the pontic in each case. After the stress patterns in surrounding tissues of the abutments were observed and recorded, the conclusions were as follows: 1. In model I, applied force was distributed to the long axis of the abutments. 2. In model II, III, IV, all the secondary abutments showed compressive stresses. No tensile stresses were developed. 3. The mesial aspect of the lateral incisor and the distal aspect of the second molar as the secondary abutment showed no compressive stresses.

[A photoelastic study of the stress distribution in the surrounding tissues of the abutments of a fixed partial denture with tilted molar abutments]

The purpose of this study was to evaluate the stress distributions to the abutments of a fixed partial denture with tilted molar abutments. In cases of the lower 1st molar being missing four 2-dimensional photoelastic models with 3- unit fixed partial dentures of which the 2nd molars were tilted 0 degrees, 10 degrees, 20 degrees and 30 degrees toward the 2nd premolar were made. A vertical load of 50 lbs was applied to the 1st and 2nd molar in each case. Two-dimensional photoelastic stress analysis was used, and the stress areas were recorded photographically. The results were as follows; 1. When the vertical load was applied to pontic and 2nd molar on the central fossae, the magnitude of stress distribution of the surrounding tissues of the root of the 2nd premolar was increased incrementally with increasing inclination. 2. Under two loading conditions, the stress distributions were directed to the long axis of the abutments. 3. In this experiment, no stress distributions were observed on the mesial area of the mesial root of the second molar.