RESUMEN
The VoxTox research programme has applied expertise from the physical sciences to the problem of radiotherapy toxicity, bringing together expertise from engineering, mathematics, high energy physics (including the Large Hadron Collider), medical physics and radiation oncology. In our initial cohort of 109 men treated with curative radiotherapy for prostate cancer, daily image guidance computed tomography (CT) scans have been used to calculate delivered dose to the rectum, as distinct from planned dose, using an automated approach. Clinical toxicity data have been collected, allowing us to address the hypothesis that delivered dose provides a better predictor of toxicity than planned dose.
RESUMEN
OBJECTIVE: The VoxTox study, linking delivered dose to toxicity requires recalculation of typically 20-37 fractions per patient, for nearly 2000 patients. This requires a non-interactive interface permitting batch calculation with multiple computers. METHODS: Data are extracted from the TomoTherapy(®) archive and processed using the computational task-management system GANGA. Doses are calculated for each fraction of radiotherapy using the daily megavoltage (MV) CT images. The calculated dose cube is saved as a digital imaging and communications in medicine RTDOSE object, which can then be read by utilities that calculate dose-volume histograms or dose surface maps. The rectum is delineated on daily MV images using an implementation of the Chan-Vese algorithm. RESULTS: On a cluster of up to 117 central processing units, dose cubes for all fractions of 151 patients took 12 days to calculate. Outlining the rectum on all slices and fractions on 151 patients took 7 h. We also present results of the Hounsfield unit (HU) calibration of TomoTherapy MV images, measured over an 8-year period, showing that the HU calibration has become less variable over time, with no large changes observed after 2011. CONCLUSION: We have developed a system for automatic dose recalculation of TomoTherapy dose distributions. This does not tie up the clinically needed planning system but can be run on a cluster of independent machines, enabling recalculation of delivered dose without user intervention. ADVANCES IN KNOWLEDGE: The use of a task management system for automation of dose calculation and outlining enables work to be scaled up to the level required for large studies.
Asunto(s)
Neoplasias de la Próstata/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Calibración , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Dosificación Radioterapéutica , Recto/diagnóstico por imagen , Recto/efectos de la radiación , Tomografía Computarizada por Rayos XRESUMEN
Few large studies have evaluated concordance based on a broad spectrum of human papillomavirus (HPV) types in oral and genital specimens of mothers and their recently born infants. This information is important in determining whether HPV vaccines administered prior to pregnancy may be useful for preventing vertical transmission. HPV DNA was positive in 30% of mothers and 1.5% of newborns. Maternal/newborn concordance (HPV+/+ or HPV-/-) was 71%. Among HPV DNA+ mothers, only 3% of their infants were DNA+ and only 1 pair had the same HPV type. Among HPV- women, 0.8% of infants were HPV+. HPV DNA detected in hospitalized newborns reflects current infection transmitted to infants during pregnancy or delivery. None of the mother/baby HPV DNA+ concordance pairs detected viral types found in HPV vaccines suggesting that vaccination prior to pregnancy is unlikely to be efficacious in preventing vertical transmission.
Asunto(s)
Alphapapillomavirus , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Infecciones por Papillomavirus/transmisión , Vacunas contra Papillomavirus/administración & dosificación , Infecciones Tumorales por Virus/transmisión , Adulto , Alphapapillomavirus/inmunología , Alphapapillomavirus/aislamiento & purificación , Anticuerpos Antivirales/sangre , Antígenos Virales/inmunología , ADN Viral/análisis , Femenino , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Humanos , Recién Nacido , Modelos Logísticos , Infecciones por Papillomavirus/congénito , Infecciones por Papillomavirus/prevención & control , Embarazo , Factores de Riesgo , Infecciones Tumorales por Virus/congénito , Infecciones Tumorales por Virus/prevención & control , Adulto JovenAsunto(s)
Migración Animal , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/epidemiología , Animales , Animales Salvajes/virología , Aves , Reservorios de Enfermedades/veterinaria , Egipto/epidemiología , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/transmisiónRESUMEN
A method of communication employing the second order statistics of photon-number squeezed light is demonstrated. The technique encodes the information content in both nonstationary noise processes and in the average optical power, thereby creating two orthogonal channels and increasing the transmission capacity. Communication via the fragile quantum state has potential applications for privatized communication.