Matsumoto, Andrew

BACKGROUND Numerous treatment modalities have been reported for squamous cell carcinoma in situ (SCCIS). Risk factors for recurrence have not been systematically reviewed. OBJECTIVE To systematically review and summarize the data on risk factors that contribute to recurrence of SCCIS. MATERIALS AND METHODS A PubMed search was completed using the terms “SCCIS,” “Bowen's disease,” “Bowen's disease and recurrence,” and “Bowen's disease and Mohs.” These sources were cross-referenced for the terms “treatment,” “management,” “therapy,” “recurrence,” and “margins.” Studies were selected on the basis of relevance and applicable treatments. RESULTS Immunosuppression was the only variable with a statistically signficant association with progression or recurrence of SCCIS. Although there were no data directly correlating subclinical lateral extension or invasive squamous cell carcinoma within SCCIS with recurrence, evidence supports both of these as common features of SCCIS. Other potential recurrence risk factors for which there are limited supporting data included tumor size, depth of follicular extension, and location. CONCLUSION Immunosuppression was the only risk factor associated with increased risk of tumor recurrence. Subclinical tumor extension and occult invasive squamous cell carcinoma are relatively common features that theoretically could increase recurrence risk. These factors should be considered when deciding upon treatment for SCCIS. Further study is required to quantify variables that influence recurrence and to identify optimal treatment options.

Purpose: Traditionally, determination of total lung capacity (TLC) by plethysmography (TLCpleth) has been important in the diagnosis of lung diseases. Alternatively, data acquired from computerized tomography (CT) can be utilized to calculate a measure of TLC (TLCCT). The clinical utility of TLCCT is not certain. We sought to determine, in a clinical setting, whether TLCCT correlates with TLCpleth across a range of lung diseases and scanning techniques. In addition, we determined whether TLCCT affects the interpretation of pulmonary function tests. Subjects and Methods: Records of 118 of 148 consecutive lung transplant recipients were reviewed and determined to have coinciding pulmonary function tests, including plethysmography as well as volumetric chest CT performed supine during full inspiration. CT images acquired with a wide range of scanning protocols were analyzed using CALIPER, a software program for lung and trachea extraction from a CT volume and volumetric tissue characterization of the lung. Segmentation of the lung was achieved by using completely automated dynamic thresholding and region-growing techniques developed to extract the relatively low-density lung and tracheal anatomy from the CT data set without user intervention. Results: TLCpleth and TLCCT were strongly related with a correlation coefficient of 0.88 (P<0.001). The efficacy of the CT-derived measure was not influenced by specific lung diagnoses, age, height, body mass index, or spirometric parameters. TLCCT did not misidentify any diagnosis of restrictive lung disease, nor hyperinflation. Conclusions: In a clinical setting, CT segmentation analysis provides a favorable determination of TLC compared with traditional plethysmography. The technique has general applicability across varying CT data acquisition protocols, lung diseases, and patient characteristics. TLCCT may substitute for TLCpleth in pulmonary function interpretation and may be preferable for some patients in whom plethysmography is difficult to perform, such as transplant subjects with severe pulmonary fibrosis.

High-frequency oscillations (HFO; gamma: 40–100 Hz, ripples: 100–200 Hz, and fast ripples: 250–500 Hz) have been widely studied in health and disease. These phenomena may serve as biomarkers for epileptic brain; however, a means of differentiating between pathological and normal physiological HFO is essential. We categorized task-induced physiological HFO during periods of HFO induced by a visual or motor task by measuring frequency, duration, and spectral amplitude of each event in single trial time-frequency spectra and compared them to pathological HFO similarly measured. Pathological HFO had higher mean spectral amplitude, longer mean duration, and lower mean frequency than physiological-induced HFO. In individual patients, support vector machine analysis correctly classified pathological HFO with sensitivities ranging from 70–98% and specificities >90% in all but one patient. In this patient, infrequent high-amplitude HFO were observed in the motor cortex just before movement onset in the motor task. This finding raises the possibility that in epileptic brain physiological-induced gamma can assume higher spectral amplitudes similar to those seen in pathologic HFO. This method if automated and validated could provide a step towards differentiating physiological HFO from pathological HFO and improving localization of epileptogenic brain.