uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Small fields: nonequilibrium radiation dosimetry
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Oncology.
2008 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 35, no 1, 206-215 p.Article, review/survey (Refereed) Published
Abstract [en]

Advances in radiation treatment with beamlet-based intensity modulation, image-guided radiation therapy, and stereotactic radiosurgery (including specialized equipments like CyberKnife, Gamma Knife, tomotherapy, and high-resolution multileaf collimating systems) have resulted in the use of reduced treatment fields to a subcentimeter scale. Compared to the traditional radiotherapy with fields > or =4 x 4 cm2, this can result in significant uncertainty in the accuracy of clinical dosimetry. The dosimetry of small fields is challenging due to nonequilibrium conditions created as a consequence of the secondary electron track lengths and the source size projected through the collimating system that are comparable to the treatment field size. It is further complicated by the prolonged electron tracks in the presence of low-density inhomogeneities. Also, radiation detectors introduced into such fields usually perturb the level of disequilibrium. Hence, the dosimetric accuracy previously achieved for standard radiotherapy applications is at risk for both absolute and relative dose determination. This article summarizes the present knowledge and gives an insight into the future procedures to handle the nonequilibrium radiation dosimetry problems. It is anticipated that new miniature detectors with controlled perturbations and corrections will be available to meet the demand for accurate measurements. It is also expected that the Monte Carlo techniques will increasingly be used in assessing the accuracy, verification, and calculation of dose, and will aid perturbation calculations of detectors used in small and highly conformal radiation beams.

Place, publisher, year, edition, pages
2008. Vol. 35, no 1, 206-215 p.
Keyword [en]
small field dosimetry, nonequilibrium conditions, Monte Carlo
National Category
Medical and Health Sciences
URN: urn:nbn:se:uu:diva-103249DOI: 10.1118/1.2815356ISI: 000251910300023PubMedID: 18293576OAI: oai:DiVA.org:uu-103249DiVA: diva2:217771
Available from: 2009-05-15 Created: 2009-05-15 Last updated: 2011-01-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Ahnesjö, Anders
By organisation
In the same journal
Medical physics (Lancaster)
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 287 hits
ReferencesLink to record
Permanent link

Direct link