Linked Life Data

16463147

Source:http://linkedlifedata.com/resource/pubmed/id/16463147

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-8-9
pubmed:abstractText
It is often assumed that radiation-induced secondary cancer after proton therapy forms preferentially close to the distal fall-off of the spread-out Bragg peak because of an increased relative biological effectiveness (RBE) with regard to cancer induction of low-energy protons. In this study we analyze to what extent dose gradients distal to the Planning Target Volume (PTV) may, independently from the RBE, contribute to enhanced radiation carcinogenesis. The study is based on two dogs which, out of 30 dogs treated with proton therapy at the Paul Scherrer Institute (PSI), developed a secondary cancer. Both dogs were originally diagnosed and treated for a fibrosarcoma and developed an osteosarcoma 48 and almost 60 months, respectively, after radiotherapy. From the dose distributions of the initial radiotherapy for both dogs three-dimensional maps of secondary cancer complication probability (SCCP) were computed. The SCCP maps were analyzed in the regions where the dogs developed a secondary cancer. The SCCP maps showed an enhanced risk in the regions of the femur where the secondary cancers were detected, as compared to the SCCP of the total femur. Excess risk of radiation-induced cancer at the distal part of proton radiation fields can thus be explained using SCCP calculations on the basis of the physical dose distributions. Therefore, the occurrence of secondary cancer close to the distal dose gradients of proton therapy is not necessarily due to an increased RBE of low-energy protons. More extensive studies based on more patients will be necessary to further elucidate the factors influencing the development of secondary tumors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0301-634X
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-43
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Is the risk for secondary cancers after proton therapy enhanced distal to the Planning Target Volume? A two-case report with possible explanations.
pubmed:affiliation
Division of Medical Physics, Department of Radiation Oncology and Nuclear Medicine, City Hospital Zürich, 8063 Zürich, Switzerland. uwe.schneider@psi.ch
pubmed:publicationType
Journal Article