Primerjava tehnik slikanj pri limfoscintigrafiji malignega melanoma glave in vratu s planarno kamero gama in programsko opremo Medicview ter SPECT/CT : magistrsko delo

Škalič, Katja (author), Škrk, Damijan (mentor), Fidler, Valentin (comentor)

Uvod: Incidenca malignega melanoma raste tako v Sloveniji, kot tudi po svetu. Je visoko maligen kožni rak, ki zaseva po limfnih poteh. Z namenom detekcije varovalnih bezgavk se izvaja limfoscintigrafija. Na Onkološkem inštitutu v Ljubljani se jo izvaja od leta 1997. Posebej za to uporabo je bila razvita oprema za zajemanje in obdelavo podatkov s planarno kamero gama. Skozi leta se je programska oprema dograjevala in dopolnjevala. Maligni melanom se lahko pojavi kjerkoli na koži in sluznici. Zaradi anatomskih karakteristik je v nalogi predstavljen maligni melanom glave in vratu. Limfoscintigrafija malignega melanoma glave in vratu zahteva poleg planarnih posnetkov še tomografske posnetke SPECT CT aparature. Namen: z nalogo sem želela natančno predstaviti obe tehniki zajemanja in obdelave podatkov pri malignem melanomu glave in vratu, tako s planarno kamero gama z uporabo MedicView programske opreme, kot tudi SPECT CT aparaturo. Pri zajemanju s planarno kamero gama sem primerjala slike z uporabo nizko energijskega in srednje energijskega kolimatorja. Metode dela: slikanje standardnega ščitničnega fantoma na planarni kameri gama z uporabo nizko in srednje energijskega kolimatorja. Za namen primerjanja zaznavanja nizkih koncentracij aktivnosti se fantom posname še na SPECT CT aparaturi. Sledi retrospektivna študija bolnikov z malignim melanomom glave in vratu posnetih s planarno kamero gama z uporabo MedicView programske opreme ter SPECT CT aparaturo. Rezultati: od 43 bolnikov je bilo pri 35 bolnikih z obema tehnikama slikanja prikazanih enako število varovalnih bezgavk, pri 8 bolnikih pa je bilo prikazanih različno število varovalnih bezgavk. Število prikazanih bezgavk z MedicView programsko opremo in število bezgavk prikazanih s SPECT CT aparaturo ni statistično značilno različno, je pa statistično različen čas od aplikacije do slikanja. V povprečju je bilo slikanje s SPECT CT aparaturo 30 min kasneje kot s planarno kamero gama in MedicView programsko opremo. Razprava in zaključek: mesto aplikacije radiofarmaka zaradi majhnega volumna in visoke aktivnosti pri uporabi nizko energijskih kolimatorjev povzroči pojav zvezda efekta, zato se limfoscintigrafije na planarni kameri z uporabo MedicView programske opreme izvaja z uporabo srednje energijskega kolimatorja. Čeprav je zaradi njega zmanjšana prostorska ločljivost v primerjavi z nizko energijskim kolimatorjem, pa na zaznavnost samo ne vpliva, saj s pomočjo posebne tehnike obdelave z MedicView programsko opremo prikažemo že bezgavke, ki so v svoji aktivnosti malenkostno nad ravnjo aktivnosti ozadja (šuma). Študija je pokazala, da se število prikazanih bezgavk pri malignem melanomu glave in vratu z uporabo različnih tehnik slikanja, tako planarne kamere gama in MedicView programske opreme, kot tudi zajemanje s SPECT CT aparaturo, statistično ne razlikuje. Je pa za detekcijo varovalnih bezgavk pri malignem melanomu glave in vratu smotrno uporabiti obe tehniki slikanja, saj se komplementarno dopolnjujeta.

• Language: Slovenian
• Keywords: limfoscintigrafija, planarna kamera gama, SPECT CT, MedicView, varovalne bezgavke, kolimatorji
• Work type: Master's thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2019
• PID: 20.500.12556/RUL-112959
• COBISS.SI-ID: 5735531
• Publication date in RUL: 24.11.2019

Secondary language

• Language: English
• Title: Comparison of conventional planar lymphoscintigraphy with Medicview software for sentinel node localization in patients with head and neck melanoma and SPECT/CT : master thesis

Abstract

Introduction: The incidence of malignant melanoma is increasing in Slovenia and worldwide. It is a highly malignant skin cancer that metastasize via lymphatic pathways to regional lymph nodes. In order to detect sentinel lymph nodes, lymphoscintigraphy is performed. At the Institute of Oncology in Ljubljana, it has been used since 1997. Specifically for this application, the processing equipment for the planar gamma camera has been developed. Over the years, the software has been upgraded and constantly developed. Malignant melanoma can occur anywhere on the skin and mucous membranes. Due to specific anatomical characteristics of the head&neck region this study addresses lymphoscintigraphy of head and neck malignant melanoma which requires planar imaging as well as tomographic imaging with SPECT CT. Aim of the study: To present in details both techniques; imaging with a planar gamma camera using the MedicView software as well as a SPECT CT. With a planar gamma camera two different collimators were used: a low-energy and a medium-energy collimator Methods: The collection of data from the planar gamma camera was done for standard thyroid phantom, using both collimators. In order to compare the detectability of low concentrations of activity, the phantom is recorded also on the SPECT CT. A retrospective study of patients with a malignant melanoma of the head& neck was performed in which both techniques a planar gamma camera as well as SPECT CT was used. Results: from 43 patients, the same number of sentinel lymph nodes were detected in 35 patients with both imaging techniques. In 8 patients, a different number of sentinel lymph nodes were detected. The number of lymph nodes detected with the MedicView software and the lymph nodes detected with the SPECT CT were not statistically significantly different, but there was a statistically significantly different time between the administration of radiopharmaceuticals and the imaging phase. The SPECT CT imaging was taken 30 minutes later than the imaging with a planar gamma camera and MedicView software. Discussion and conclusion: The location of the radiopharmaceuticals administration due to low volume and high activity in the use of low energy collimators results in the appearance of a star effect, therefore lymphoscintigraphy on a planar gamma camera using MedicView software is carried out using a medium energy collimator. Although the imaging spatial resolution is reduced it does not affect the detection itself. Lymph nodes with the activity slightly above the level of background activity (noise) were displayed. There is no statistical difference in the number of the displayed lymph nodes when using both imaging techniques: the planar gamma camera with MedicView software and the SPECT CT. However, for the detection of sentinel lymph nodes in malignant melanoma of the head&neck region, it is appropriate to use both techniques of imaging, as they are complementary.

• Keywords: lymphoscintigraphy, planar gamma camera, SPECT CT, MedicView, sentinel lymph nodes, collimators