The impact of linac output variations on dose distributions in helical tomotherapy

Physics in Medicine and Biology
Ryan T FlynnT Rock Mackie

Abstract

It has been suggested for quality assurance purposes that linac output variations for helical tomotherapy (HT) be within +/-2% of the long-term average. Due to cancellation of systematic uncertainty and averaging of random uncertainty over multiple beam directions, relative uncertainties in the dose distribution can be significantly lower than those in linac output. The sensitivity of four HT cases with respect to linac output uncertainties was assessed by scaling both modeled and measured systematic and random linac output uncertainties until a dose uncertainty acceptance criterion failed. The dose uncertainty acceptance criterion required the delivered dose to have at least a 95% chance of being within 2% of the planned dose in all of the voxels in the treatment volume. For a random linac output uncertainty of 5% of the long-term mean, the maximum acceptable amplitude of the modeled, sinusoidal, systematic component of the linac output uncertainty for the four cases was 1.8%. Although the measured linac output variations represented values that were outside of the +/-2% tolerance, the acceptance criterion did not fail for any of the four cases until the measured linac output variations were scaled by a factor of almost three....Continue Reading

References

Mar 1, 1991·Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology·A Niemierko, M Goitein
Jan 1, 1988·Physics in Medicine and Biology·T R MackieJ J Battista
Nov 7, 1998·International Journal of Radiation Oncology, Biology, Physics·D A LowJ A Purdy
Mar 13, 1999·Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology·D A LowJ A Purdy
Mar 17, 1999·Medical Physics·J P BalogD Pearson
Apr 10, 1999·Seminars in Radiation Oncology·T R MackieM Mehta
Feb 8, 2000·Physics in Medicine and Biology·D M ShepardT R Mackie
Apr 16, 2003·International Journal of Radiation Oncology, Biology, Physics·Shiao Y WooE Brian Butler
Aug 3, 2004·Physics in Medicine and Biology·J D FenwickB R Paliwal
Apr 1, 1994·Physics in Medicine and Biology·P W HobanW H Round
Jun 30, 2005·Medical Physics·M W KissickE T Soisson
Jun 23, 2006·Physics in Medicine and Biology·T R Mackie

❮ Previous
Next ❯

Citations

Aug 20, 2008·Physics in Medicine and Biology·Michael W KissickRobert Jeraj
Dec 11, 2013·Medical Physics·Yunlong LiuXiaodong Wu
May 3, 2013·Medical Physics·Yunlong LiuXiaodong Wu
Jan 18, 2014·Medical Dosimetry : Official Journal of the American Association of Medical Dosimetrists·David ChapmanSlav Yartsev
Oct 23, 2010·Medical Physics·Katja M LangenUNKNOWN AAPM Task Group 148
Aug 2, 2014·Zeitschrift für medizinische Physik·Paola CaprileEdgardo Doerner
Jun 24, 2015·Journal of Applied Clinical Medical Physics·Zoë R MoutrieLitang Yu
Jan 11, 2012·Journal of Applied Clinical Medical Physics·Vincent AlthofAndre Minken
Jun 29, 2011·Physics in Medicine and Biology·F AlbertiniA J Lomax
Oct 14, 2021·Physics in Medicine and Biology·Peter FerjančičRobert Jeraj

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.