26 nov. STUDIU SCINTIMAMOGRAFIC SEMICANTITATIV CU 99MTC MIBI IN EVALUAREA RASPUNSULUI LA CHIMIOTERAPIA NEO-ADJUVANTA A CARCINOMULUI DE SÂN LOCAL AVANSAT
Saima Haider*,Ioan Codorean**, Gabriela Simona Toma**
* Clinica de Radiologie, Imagistica Medicala si Medicina Nucleara, UMF “Carol Davila” Bucuresti
** Spitalul Clinic de Urgenta Militar Central, UMF “Carol Davila” Bucuresti
Rezumat
Scop: Chimioterapia neo-adjuvanta este indicata pentru reducerea stadiului evolutiv al pacientelor cu cancer de san local avansat preoperator si pentru a prelungi supravietuirea dupa interventia chirurgicala.
Evaluarea raspunsului la chimioterapie nu poate fi facuta cu acuratete mai devreme datorita limitelor examenului clinic si ale altor metode disponibile. Scopul acestui studiu este de a determina rolul scintimamografiei efectuata cu 99mTc MIBI (MSM) în evaluarea precoce si precisa a raspunsului la chimioterapie prin analiza semicantitativa a captarii trasorului.
Metoda: Au fost analizate imaginile obtinute de la 16 paciente cu neoplasm de san local avansat, care nu beneficiasera de radio- si/sau chimioterapie anterior. S-au injectat intravenos în medie 950MBq de 99mTc MIBI la nivelul bratului opus leziunii. S-au efectuat achizitii statice timp de 10 minute cu pacientele în clinostatism ventral, mai întai la nivelul sanului afectat si apoi si la cel controlateral la 5 – 10 min dupa injectare. Au fost obtinute background-substracted lesions to normal ratios (LNR) prin desenarea de regiuni de interes (ROIs) la nivelul celui mai fierbinte punct al leziunii, atat pe imaginile obtinute înainte de initierea terapiei, cat si pe cele posttratament. Apoi a fost formulat un sistem de scor pentru notarea categoriei de raspuns pentru aprecierea raspunsului clinic, calitativ si cantitativ. Rezultatele calitative si cantitative au fost analizate statistic.
Rezultate: Rezultatele au dus la concluzia ca MSM poate prezice raspunsul la chimioterapie cu acuratete si siguranta crescute, întrucat a existat o corelatie pozitiva (cantitativ r = 0,805, P < 0,01 si calitativ r = 0,638, P < 0,01) între evaluarea clinica si analizele vizuale si semicantitative. MSM semicantitativa pare a putea anticipa mai corect raspunsul decat analizele clinice si cantitative.
Concluzii: in ciuda a catorva limite, studiul de fata demonstreaza ca scintimamografia cu 99mTc MIBI poate prezice raspunsul la chimioterapia neo-adjuvanta mai devreme decat evaluarea clinica. Drept urmare, joaca un rol important în diferentierea grupurilor responsive si neresponsive la tratament.
Abstract – SCINTIMAMMOGRAPHICAL SEMIQUANTITATIVE STUDY WITH 99MTC MIBI FOR EVALUATING THE RESPONSE TO NEO-ADJUVANT CHMOTHERAPY OF LOCALLY ADVANCED BREAST CARCINOMA
Objective: Neo adjuvant chemotherapy is inidcated for the preoperative reduction of the evolutive stage in locally advanced breast cancer patients and to increase survival rates following the surgical intervention. Evaluation of the chemotherapy response cannot be accurately made earlier because of the limitations of the clinical examination and other available methods. The aim of this study is is to determine the role of 99mTc MIBI scitimammography (MSM) in the early and precise evaluation of chemotherapy response by semiquatitative analysis of the marker capture.
Method: Images acquired from 16localy advanced breast cancer patients were analysed, none of them having previously received radio or/and chemotherapy. An average 950Bq 99mTc MIBI were intravenously injected into the contralateral arm (considering the lesion). Statical aquisitons were made for 10 minutes, with the patients in ventral clinostatism, first at the level of the affected breast and then at the contralateral breast level, 10-15 minutes after the injection. Background-substractd lesions to normal ratios (LNR) were obtatined by drawing regios of interest (ROIs) at the level of the hottest point of the lesion, both on the images obtatined before initiating the therapy, as well as those post-treatment. Then, a scoring system was conceived to appreciate the clinical response category, qualitatively and quantitatively. The results were statistically analysed.
Results: The resulta obtained led to the conclusion that MSM can predict the chemotherapy response with increased accuracy and safety, as we found a positive correlation (quantitatively r = 0,805, P < 0,01 and qualitatively r = 0,638, P < 0,01) between the clinical evaluation and the visula and semiquantitative analyses. Semiquantitative MSM seems to be able to more correctly anticipate the answer than clinical and semiquantitative analses.
