Accuracy of 131I tumor quantification in radioimmunotherapy using SPECT imaging with an ultra-high-energy collimator: Monte Carlo study

↓ Direkt till sidans innehåll
↓ Direkt till sidans sekundära innehåll (sidomenyn)

Sökning: (L773:0161 5505 OR L773:2159 662X) srt2:(2000-2004) > Accuracy of 131I tu...

Dewaraja, Y K (författare)

Accuracy of 131I tumor quantification in radioimmunotherapy using SPECT imaging with an ultra-high-energy collimator: Monte Carlo study

Artikel/kapitelEngelska2000

Förlag, utgivningsår, omfång ...

2000

Nummerbeteckningar

LIBRIS-ID:oai:lup.lub.lu.se:eb0b2554-a3c1-4dc3-8ba9-36dd225ea45c
https://lup.lub.lu.se/record/1117529URI

Kompletterande språkuppgifter

Språk:engelska
Sammanfattning på:engelska

Ingår i deldatabas

SwePubSwePub

Klassifikation

Ämneskategori:art swepub-publicationtype
Ämneskategori:ref swepub-contenttype

Anmärkningar

Accuracy of 131I tumor quantification after radioimmunotherapy (RIT) was investigated for SPECT imaging with an ultra-high-energy (UHE) collimator designed for imaging 511-keV photons. METHODS: First, measurements and Monte Carlo simulations were carried out to compare the UHE collimator with a conventionally used, high-energy collimator. On the basis of this comparison, the UHE collimator was selected for this investigation, which was carried out by simulation of spherical tumors in a phantom. Reconstruction was by an expectation-maximization algorithm that included scatter and attenuation correction. Keeping the tumor activity constant, simulations were carried out to assess how volume-of-interest (VOI) counts vary with background activity, radius of rotation (ROR), tumor location, and size. The constant calibration factor for quantification was determined from VOI counts corresponding to a 3.63-cm-radius sphere of known activity. Tight VOIs corresponding to the physical size of the spheres or tumors were used. RESULTS: Use of the UHE collimator resulted in a large reduction in 131I penetration, which is especially significant in RIT where background uptake is high. With the UHE collimator, typical patient images showed an improvement in contrast. Considering the desired geometric events, sensitivity was reduced, but only by a factor of 1.6. Simulation results for a 3.63-cm-radius tumor showed that VOI counts vary with background, location, and ROR by less than 3.2%, 3%, and 5.3%, respectively. The variation with tumor size was more significant and was a function of the background. Good quantification accuracy (<6.5% error) was achieved when tumor size was the same as the sphere size used in the calibration, irrespective of the other parameters. For smaller tumors, activities were underestimated by up to -15% for the 2.88-cm-radius sphere, -23% for the 2.29-cm-radius sphere, and -47% for the 1.68-cm-radius sphere. CONCLUSION: Reasonable accuracy can be achieved for VOI quantification of 131I using SPECT with an UHE collimator and a constant calibration factor. Difference in tumor size relative to the size of the calibration sphere had the biggest effect on accuracy, and recovery coefficients are needed to improve quantification of small tumors.

Ämnesord och genrebeteckningar

Biuppslag (personer, institutioner, konferenser, titlar ...)

Ljungberg, MichaelLund University,Lunds universitet,Medicinsk strålningsfysik, Lund,Sektion V,Institutionen för kliniska vetenskaper, Lund,Medicinska fakulteten,Medical Radiation Physics, Lund,Section V,Department of Clinical Sciences, Lund,Faculty of Medicine(Swepub:lu)rafy-mlj (författare)
Koral, K F (författare)
Medicinsk strålningsfysik, LundSektion V (creator_code:org_t)

Sammanhörande titlar

Ingår i:Journal of Nuclear Medicine41:10, s. 1760-17600161-5505

Internetlänk

Hitta via bibliotek

Journal of Nuclear Medicine (Sök värdpublikationen i LIBRIS)

Till lärosätets databas

Hitta mer i SwePub

Av författaren/redakt...: Dewaraja, Y K; Ljungberg, Micha ...; Koral, K F

Om ämnet

MEDICIN OCH HÄLSOVETENSKAP: MEDICIN OCH HÄLS ...; och Klinisk medicin; och Radiologi och bi ...

Artiklar i publikationen: Journal of Nucle ...

Av lärosätet: Lunds universitet

Sök utanför SwePub

Sök vidare i:: Google; Google Book Search; Google Scholar

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

LIBRIS.kb.se