The use of the NSD concept in practical radiotherapy is simplified by introduction time, dose, and fractionation (TDF) factors, which are proportional to partial tolerances, but not dependent upon any specific value. Detailed examples given utilization TDF factor tables, simple use, general application, help ensure correct interpretation basic concepts. Computers, slide-rules, or even log requires.

A model for the dependence of normal tissue radiation dose response functions on volume variations and inhomogeneities is derived using probability theory. Power law correction factors complication factor are shown to be special cases arising from approximations applied this model. Both require assumption small probabilities complication. corrections a homogeneous distribution. The general specific can used calculate individual organs or isoprobability doses injury. applicable both...

The time, dose, and fractionation (TDF) factor simplification of the nominal standard dose concept in fractionated radiotherapy has been extended to brachytherapy. method automatically compensates for variation biological effect with dose-rate time application is therefore applicable irradiation at effectively constant (with 226Ra, 137Cs, 60Co, etc.) varying 222Rn, 198Au, 192Ir, 182Ta, etc.), permanent temporary implants. Tables brachytherapy TDFs are easy use and, combination TDF tables,...

For adaptive radiotherapy it is common to collect images of the patient throughout course therapy. Because temporal variations, however, usually necessary deform so as merge them into a cohesive dataset. This image registration makes accurate merging dose distributions difficult, if not impossible. Some have decided do this by "deforming" distributions, somewhat analogous deforming images, but has been suggested that appropriate. premise debated in monthˈs Point/Counterpoint. Arguing for...

Arguing against the Proposition is David J. Brenner, Ph.D., D.Sc. Dr. Brenner a Professor of Radiation Oncology and Public Health at Columbia University Medical Center. He focuses on developing models for carcinogenic effects ionizing radiation living systems chromosomal, cellular, tissue, organism levels. divides his research time roughly equally between high doses (related to therapy) low radiological, environmental, occupational exposures). When not involved in matters, he supports...

With the combination of PET and CT images in dual-modality PET/CT units, it is now possible to accurately align functional information obtained with anatomical structures revealed by CT. This a significant improvement over previous methods combining these two modalities "fusing" sequential studies, all problems associated precise patient positioning. The oncological community has so embraced this new technology that units are becoming commonplace. Indeed, rarely purchased without being...

Arguing against the Proposition is Ruimin Ma, M.S. Mr. Ma obtained his B.S. from Shanxi University in 2000 and Wuhan University, Wuhan, People's Republic of China, 2004. He currently completing research for Ph.D. Informatrics at where he an assistant researcher Research Centre Chinese Scientific Evaluation. His major interest scientometrics, especially domain analysis, visualization, evaluation competitiveness. has participated as one leaders several projects other universities, academic...

Arguing against the Proposition is Andrea Molineu, M.S. Ms. Molineu obtained her in Medical Physics from University of Kentucky, Lexington 1999 and then moved to Department Radiation Oncology, St. Elizabeth's Center, Boston, where she held a Physicist appointment until 2001. She Radiological Physics, Division UT M. D. Anderson Cancer Houston, TX, currently Senior Associate Director MD Phantom Laboratory. certified by American Board Radiology Therapeutic major research interests include...

The effects of X-radiation on the infectivity and development sporozoites Plasmodium berghei were determined. When susceptible mice injected with X-irradiated sporozoites, results showed that higher dose radiation, smaller percentage developed patent blood infections. Sporozoites irradiated more than 10,000 rads failed to produce any Small, but apparently mature, exoerythrocytic forms found in livers rats had been sporozoites. Such numerous after a low i.e., 2,000 rads, persist liver for at...

With impressive progress in machine learning, there has been increasingly more interest its relevance to medical physics, which involves both imaging and radiation treatment planning. However, because it is still generally unclear how identify unique niches, utilize big data, optimize neural networks, learning yet have a major impact on physics practice. Nevertheless, are optimistic opinions that will radiology within the next 5 years. This premise debated this month's Point/Counterpoint....

A method is presented by which dose distributions in radiotherapy may be judged. This method, based on statistical decision theory, combines the calculated probabilities of radiation induced complications (including failure to control disease) with therapist's judgment morbidity each complication yield a single value representing clinical utility distribution. Using this figure merit, alternative can compared basis. If morbidities associated injury are satisfactorily estimated, and response...

With the increased use of normal tissue sparing highly conformal therapy it has become possible to treat patients with fewer treatments at high dose/fraction. Fewer fractions, however, mean opportunities for radioresistant hypoxic cells reoxygenate during course treatment and this might reduce tumor control. It been suggested that hypoxia is an important consideration such hypofractionated regimes, and, as such, should be considered in planning. This concern debated month's...

Arguing against the Proposition is Mark P. Little, D.Phil. Dr. Little obtained his in Mathematics from New College, Oxford 1985. He then worked for next six years at British Coal, Harrow, London, and Berkeley Nuclear Laboratories, Electric, Berkeley, UK. continued with career epidemiology first as Principal Scientific Officer, Epidemiology Group, NRPB, Chilton, UK, Department of Biostatistics, Imperial College Faculty Medicine, In 2010 he moved to USA Senior Investigator Radiation Branch,...