Author/Editor     Jarm, Tomaž; Lešničar, Hotimir; Serša, Gregor; Miklavčič, Damijan
Title     First experience with a novel luminescence-based optical sensor for measurement of oxygenation in tumors
Translated title     Prve izkušnje z novo luminiscenčno optično metodo za merjenje oksigenacije v tumorjih
Type     članek
Source     Radiol Oncol
Vol. and No.     Letnik 35, št. 4
Publication year     2001
Volume     str. 277-91
Language     eng
Abstract     Background. The purpose of this preliminary study was to evaluate a novel luminescence-based fiber-optic sensor (OxyLite system) for the measurement of partial pressure of oxygen (pO2) in tumors and for the detection of changes in pO2 as a function of time. The new method was used simultaneously with the laser Doppler flowmetry method for the measurement of relative tissue perfusion. Materials and methods. Blood perfusion and pO2 were measured continuously via fiber-optic sensors inserted into SA-1 tumors in anesthetized A/J mice. The changes in blood flow and oxygenation of tumors were induced by transient changes of the parameters of anesthesia and by injection of a vasoactive drug hydralazine. Results. Both optical methods used in the study successfully detected the induced changes in blood flow and pO2. The measurements of pO2 were well correlated with measurements of microcirculatory blood perfusion. In the majority of pO2 measurements, we observed an unexpected behavior of the signal during the stabilization process immediately after the insertion of the probe into tumor. This behaviour of the pO2 signal was most probably caused by local tissue damage induced by the insertion of the probe. Conclusion. The novel luminescence-based optical oximetry can reliably detect local pO2 changes in tumors as a function of time but some aspects of prolonged pO2 measurement by this method require further investigation.
Summary     Izhodišča. S to uvodno študijo smo želeli predvsem ugotoviti uporabnost nove luminescenčne optične metode (sistem OxyLite) za merjenje delnega tlaka kisika v tumorjih (pO2) in za časovno spremljanje sprememb pO2. Hkrati s to novo metodo smo uporabili optično metodo laser Doppler, s katero lahko merimo relativni pretok krvi v tkivu. Materijal in metode. Meritve smo opravili na tumorjih SA-1 pri miših A/J, ki so bile med poskusi anestetizirane. Za časovno zvezno zajemanje meritev pO2 in pretoka krvi smo uporabili senzorje v obliki optičnih vlaken, ki smo jih vstavili v tumor. S spreminjanjem koncentracije vdihanega anestetika in z uporabo vazoaktivne učinkovine hidralazin smo izzvali spremembe v pretoku krvi in oksigenaciji. Rezultati. Rezultati so pokazali, da sta v splošnem obe merilni metodi uspešno zaznali spremembe v pretoku krvi oziroma pO2. Izmerjene spremembe pO2 in spremembe v mikrocirkulaciji so bile v tesni korelaciji. V večffni meritev pO2 smo naleteli na nepričakovan potek signala med umirjanjem izmerjene vrednosti takoj po vstavitvi merilne sonde. Tak potek signala je najverjetneje posledica lokalnih poškodb tkiva, ki nastanejo med vstavljanjem sonde v tumor. Zaključek. Nadaljne reziskave bodo potrebne za podrobnejšo osvetlitev tega vidika meritev z wovo luminescenčno optično metodo za merjenje oksigenacije.
Descriptors     SARCOMA, EXPERIMENTAL
OXIMETRY
LASER-DOPPLER FLOWMETRY
MICE
LUMINESCENCE
HYDRALAZINE
ANESTHETICS