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Prostascint Scan - ktoś coś wie?

Nieprzeczytany post: 24 sie 2016, 16:08
autor: Mac
Mam do Was pytanie: czy ktoś z Was może wie coś więcej na temat badania prostacint scan. Ja dotarłem tylko do materiałów firmy, która to badanie oferuje, ale mam ograniczone zaufanie do "sprzedawców". :)
Tu informacja z wikipedii: https://en.wikipedia.org/wiki/Indium_(111In)_capromab_pendetide
Natomiast sama idea wydaje się być ciekawa, czyli wyszukiwanie komórek rakowych przez znaczone radioaktywne przeciwciała.
Może mogłoby to pomóc w wyborze optymalnego leczenia w razie wznowy, bez strzelania w ciemno.
Pozdrawiam Maciek

Re: Prostascint Scan - ktoś coś wie?

Nieprzeczytany post: 24 sie 2016, 22:26
autor: mrakad
Trochę na ten temat znajdziesz tutaj:
http://www.urologiapolska.pl/artykul.php?2189
Autorzy sugerują, że scyntygrafia z znacznikiem Ind 111 może być czulsza od standardu z technetem 99 i dokładniej opisywać zmiany przerzutowe do kości.

Re: Prostascint Scan - ktoś coś wie?

Nieprzeczytany post: 25 sie 2016, 01:49
autor: bela71
Według protokołu amerykańskiego dostawcy usług medycznych z 2015 (https://www.bsneny.com/content/dam/COMM ... _60137.pdf) (zaznzaczenia w tekście pochodzą ode mnie)

Description
Radioimmunoscintigraphy (RIS) involves the administration of radiolabeled monoclonal antibodies (MAbs), which are directed against specific molecular targets, followed by imaging with an external gamma camera. Indiumv-111 capromab pendetide (ProstaScint®) is a monoclonal antibody directed against a binding site on prostate-specific antigen (PSA).
Summary of Evidence
Radioimmunoscintigraphy (RIS) imaging with Indium-111 (In-111) capromab pendetide (ProstaScint) is an alternative imaging modality for patients with prostate cancer that is intended to assist in determining the extent and location of disease. For determining whether disease is present in the lymph nodes, RIS has a modest
sensitivity, estimated at 50% to 75%, and a moderate to high specificity, estimated at 72% to 93%.
Because other imaging modalities have a suboptimal sensitivity for disease in the lymph nodes, RIS has been proposed to be used for staging before curative treatment. However, no studies have demonstrated that use of RIS for this
purpose changes management
, and therefore the evidence is insufficient to determine whether RIS improves health outcomes when used to stage prostate cancer pretreatment.
For patients with biochemical failure following curative treatment, RIS has been proposed to help differentiate between local and distant recurrence. There are numerous small case series that evaluate RIS in this population, and describe rates of positivity for local and distant disease. However, none of these studies demonstrate a
change in management as a result of RIS. As a result, it is not possible to determine whether use of RIS in this population improves outcomes. For these reasons, RIS with In-111 capromab pendetide is considered investigational.
(...)

Background
Radioimmunoscintigraphy is an imaging modality that uses radiolabeled MAbs to target specific tissue types. MAbs that react with specific cellular antigens are conjugated with a radiolabeled isotope. The labeled antibody-isotope conjugate is then injected into the patient and allowed to localize to the target over a two - to seven-day period. The patient then undergoes imaging with a nuclear medicine gamma camera, and radioisotope counts are analyzed. Imaging can be performed with planar techniques or by using single photon emission computed tomography.
Regulatory Status
In-111 capromab pendetide (ProstaScint®) (also referred to as CYT-356) targets an intracellular binding site on prostate specific membrane antigen (PSMA) and has been approved by FDA for use as a “diagnosing imaging agent in newly diagnosed patients with biopsy-proven prostate cancer, thought to be clinically localized after standard diagnostic evaluation, who are at risk for pelvic lymph node metastases and in postprostatectomy patients with a rising prostate specific antigen (PSA) and a negative or equivocal standard metastatic evaluation in whom there is a high clinical suspicion of occult metastatic disease.” Other monoclonal antibodies, directed at extracellular PSMA binding sites, are also under development.


W skrócie: dopuszczony przez FDA, czułość w pokazywaniu zajętych węzłów szacowana na 50% do 75%, a specyficzność - 72%-93%, co i tak daje lepszy wynik niż inne badania obrazowe. Nie udowodniono, że wpływa na zmianę leczenia, więc stosowanie traktuje się jako badawcze.

Według tej prezentacji (niezłe obrazki i ciekawa analiza kosztów i opłacalności), ProstaScint
http://apps.snm.org/docs/CME/PresenterI ... Gordon.pdf
dobrze pokazuje zaatakowane węzły, twierdzą, że lepiej od MRI i TK. Idealna byłaby fuzja z jedną z tych dwóch technik.