Evaluation of an automated deformable image matching method for quantifying lung motion in respiration-correlated CT images

We have evaluated an automated registration procedure for predicting tumor and lung deformation based on CT images of the thorax obtained at different respiration phases. The method uses a viscous fluid model of tissue deformation to map voxels from one CT dataset to another. To validate the deformable matching algorithm we used a respiration-correlated CT protocol to acquire images at different phases of the respiratory cycle for six patients with nonsmall cell lung carcinoma. The position and shape of the deformable gross tumor volumes (GTV) at the end-inhale (EI) phase predicted by the algorithm was compared to those drawn by four observers. To minimize interobserver differences, all observers used the contours drawn by a single observer at end-exhale (EE) phase as a guideline to outline GTV contours at EI. The differences between model-predicted and observer-drawn GTV surfaces at EI, as well as differences between structures delineated by observers at EI (interobserver variations) were evaluated using a contour comparison algorithm written for this purpose, which determined the distance between the two surfaces along different directions. The mean and 90% confidence interval for model-predicted versus observer-drawn GTV surface differences over all patients and all directions were 2.6 and 5.1 mm, respectively, whereas the mean and 90% confidence interval for interobserver differences were 2.1 and 3.7 mm. We have also evaluated the algorithm's ability to predict normal tissue deformations by examining the three-dimensional (3-D) vector displacement of 41 landmarks placed by each observer at bronchial and vascular branch points in the lung between the EE and EI image sets (mean and 90% confidence interval displacements of 11.7 and 25.1 mm, respectively). The mean and 90% confidence interval discrepancy between model-predicted and observer-determined landmark displacements over all patients were 2.9 and 7.3 mm, whereas interobserver discrepancies were 2.8 and 6.0 mm. Paired t tests indicate no significant statistical differences between model predicted and observer drawn structures. We conclude that the accuracy of the algorithm to map lung anatomy in CT images at different respiratory phases is comparable to the variability in manual delineation. This method has therefore the potential for predicting and quantifying respiration-induced tumor motion in the lung.     

Weathering the storm: challenges to nurses providing care to nursing home residents during hurricanes

This article documents the experience of 291 Florida nursing homes during the 2004 hurricane season. Using quantitative and qualitative methods, the authors described and compared the challenges nurses encountered when evacuating residents with their experiences assisting residents of facilities that sheltered in place. The primary concerns for evacuating facilities were accessing appropriate evacuation sites for residents and having ambulance transportation contracts honored. The main issue for facilities that sheltered in place was the length of time it took for power to be restored. Barriers to maintaining resident health during disasters for those who evacuated or sheltered in place are identified.     

Giant proliferating trichilemmal cyst arising from a nevus sebaceus growing for 30 years

Nevus sebaceus of Jadassohn, a congenital cutaneous hamartoma, has the potential to develop into various epidermal adnexal‐origin neoplasms. While the most common neoplasms are trichoblastoma or syringocystadenoma, proliferating trichilemmal cysts are exceptionally rare. We report a case of a 63‐year‐old Cuban male with a giant proliferating trichilemmal cyst arising from a nevus sebaceus on the right shoulder which had been growing for 30 years. Proliferating trichilemmal cysts arising from nevus sebaceus cases are difficult to diagnose clinically and histologically as they are very rare and have not been defined by exact diagnostic criteria. Our case creates awareness of this particular tumor in nevus sebaceus and shares clinical and histological diagnostic information that can be used to make a proper diagnosis.     

Effects of the PREMIER Interventions on Health-Related Quality of Life

Background  

Health-related quality of life (HRQOL) is an important aspect of well-being that may improve with health behavior interventions. However, health behavior change is difficult with pressure to maintain status quo.     

Cross‐Imaging Platform Comparison of Ultrasonic Backscatter Coefficient Measurements of Live Rat Tumors

Objective. To translate quantitative ultrasound (QUS) from the laboratory into the clinic, it is necessary to demonstrate that the measurements are platform independent. Because the backscatter coefficient (BSC) is the fundamental estimate from which additional QUS estimates are calculated, agreement between BSC results using different systems must be demonstrated. This study was an intercomparison of BSCs from in vivo spontaneous rat mammary tumors acquired by different groups using 3 clinical array systems and a single‐element laboratory scanner system. Methods. Radio frequency data spanning the 1‐ to 14‐MHz frequency range were acquired in 3 dimensions from all animals using each system. Each group processed their radio frequency data independently, and the resulting BSCs were compared. The rat tumors were diagnosed as either carcinoma or fibroadenoma. Results. Carcinoma BSC results exhibited small variations between the multiple slices acquired with each transducer, with similar slopes of BSC versus frequency for all systems. Somewhat larger variations were observed in fibroadenomas, although BSC variations between slices of the same tumor were of comparable magnitude to variations between transducers and systems. The root mean squared (RMS) errors between different transducers and imaging platforms were highly variable. The lowest RMS errors were observed for the fibroadenomas between 4 and 5 MHz, with an average RMS error of 4 × 10^?5 cm^?1Sr^?1 and an average BSC value of 7.1 × 10^?4 cm^?1Sr^?1, or approximately 5% error. The highest errors were observed for the carcinoma between 7 and 8 MHz, with an RMS error of 1.1 × 10^?1 cm^?1Sr^?1 and an average BSC value of 3.5 × 10^?2 cm^?1Sr^?1, or approximately 300% error. Conclusions. This technical advance shows the potential for QUS technology to function with different imaging platforms.     

Intensity-modulated radiation therapy (IMRT) for inoperable non-small cell lung cancer: the Memorial Sloan-Kettering Cancer Center (MSKCC) experience.

INTRODUCTION: Intensity-modulated radiation therapy (IMRT) is an advanced treatment delivery technique that can improve the therapeutic dose ratio. Its use in the treatment of inoperable non-small cell lung cancer (NSCLC) has not been well studied. This report reviews our experience with IMRT for patients with inoperable NSCLC. METHODS AND MATERIALS: We performed a retrospective review of 55 patients with stage I-IIIB inoperable NSCLC treated with IMRT at our institution between 2001 and 2005. The study endpoints were toxicity, local control, and overall survival. RESULTS: With a median follow-up of 26 months, the 2-year local control and overall survival rates for stage I/II patients were 50% and 55%, respectively. For the stage III patients, 2-year local control and overall survival rates were 58% and 58%, respectively, with a median survival time of 25 months. Six patients (11%) experienced grade 3 acute pulmonary toxicity. There were no acute treatment-related deaths. Two patients (4%) had grade 3 or worse late treatment-related pulmonary toxicity. CONCLUSIONS: IMRT treatment resulted in promising outcomes for inoperable NSCLC patients.     

Incorporation of process preferences within the QALY framework: a study of alternative methods.

OBJECTIVE: This article explores the implications of incorporating process preferences using time tradeoff and standard gamble methods to assess the benefits of health care. METHODS: Data were derived from 2 sources: a randomized controlled trial of alternative palliative care treatments (plastic stents, thermal ablation, or brachytherapy) for esophageal cancer, and a valuation survey conducted among individuals who had previously undergone curative treatment for such cancer. Costs and quality-adjusted life years (QALYs) associated with different palliative treatments in terms of health outcome values were compared to costs and QALYs based on process values derived from 3 different treatment allocation methods: 1) receipt of most preferred treatment; 2) receipt of least preferred treatment; and 3) mean process values. RESULTS: Process values produced a different number of QALYs and QALY gains compared to those derived from health outcome values. However, treatment recommendations based on process values corresponded with those based on health outcome values: brachytherapy was identified as the more cost-effective treatment in terms of the incremental cost-per-QALY ratio by both the standard health outcome values approach and methods based on process values. These findings were supported by probabilistic analysis using the net monetary benefit framework. CONCLUSIONS: Estimation of process preferences provides additional information to policy makers in judgments over the cost-effectiveness of health care programs. These methods offer a promising alternative to standard cost-per-QALY estimation using health outcomes. However, further research examining the role of process preferences in decision making in other clinical applications appears warranted.     

Effect of acute ethanol administration and acute allopregnanolone administration on spontaneous hippocampal pyramidal cell neural activity

We investigated the effect of acute ethanol administration and acute allopregnanolone administration on spontaneous hippocampal pyramidal cell neural activity. Both agents produced significant reductions in spontaneous firing rate of hippocampal pyramidal neurons at a medium and high doses. Furthermore, blockade of allopregnanolone biosynthesis by preadministration of finasteride, a 5alpha-reductase blocker, prevented ethanol-induced inhibition on hippocampal pyramidal neural activity. The results further demonstrate similar effects of allopregnanolone and ethanol on hippocampal neurophysiology and that allopregnanolone plays a key role in producing ethanol-induced inhibition of hippocampal neural activity.     

Dose-volume factors contributing to the incidence of radiation pneumonitis in non-small-cell lung cancer patients treated with three-dimensional conformal radiation therapy

PURPOSE: To analyze acute lung toxicity data of non-small-cell lung cancer patients treated with three-dimensional conformal radiation therapy in terms of dosimetric variables, location of dose within subvolumes of the lungs, and models of normal-tissue complication probability (NTCP). METHODS AND MATERIALS: Dose distributions of 49 non-small-cell lung cancer patients treated in a dose escalation protocol between 1992 and 1999 were analyzed (dose range: 57.6-81 Gy). Nine patients had RTOG Grade 3 or higher acute lung toxicity. Correlation with dosimetric and physical variables, as well as Lyman and parallel NTCP models, was assessed. Lungs were evaluated as a single structure, as superior and inferior halves (to assess significance of dose to upper and lower lungs), and as ipsilateral and contralateral lungs. RESULTS: For the whole lung, Grade 3 or higher pneumonitis was significantly correlated (p 0.5 for superior lung indices, and >0.1 for contralateral lung indices studied). CONCLUSIONS: For these patients, commonly used dosimetric and NTCP models are significantly correlated with >or= Grade 3 pneumonitis. Equivalently strong correlations are found in the lower portion of the lungs and the ipsilateral lung, but not in the upper portion or contralateral lung.