Poster
# 10
Poster |
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6th Internet World Congress for Biomedical Sciences |
Francisca Mulero(1), V. Roca(2), F. Nicolás(3), Francisca Mulero(4), J.A. Nuño de la Rosa(5)
(1)(4)(5)Hospital Universitario Virgen de la Arrixaca - San Miguel de Salinas. Spain
(2)(3)Servicio de Medicina Nuclear. Hospital Universitario Virgen de la Arrixaca (Murcia) - Murcia. Spain
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[Oncology] |
[Radiology & Nuclear Medicine] |
MIBI-Tc99m is a tumor-seeking agent used in diagnosis of breast carcinomas. The mechanism by which it concentrates in the malignant tissue is unknown. Certain breast tumors do not show MIBI-Tc99m uptake. False negatives and false positives DO EXISTS!
The aim of our study was to determine the correlation between MIBI -Tc99m uptake and histopathological parameters of breast tumor aggressiveness.
Patients: 84 female patients with diagnosed breast carcinoma (52.1 ± 12.7)(age 22-81 years). All patients were scheduled for radical surgery.
Method: 99mTc-MIBI imaging according to the protocol in our institution: 740-925 MBq (Cardiolite® from DuPont Pharma) injected EV in an antecubital vein contralateral to the breast undergoing evaluation.
Planar images. 256 x 256 pixels (0.2210 cm/pixel) in a single head gammacamera with LEHR collimator. 10% window centered at Technetium´s photopeak. Prone position. Special positioning device. Imaging 5 and 90 minutes after injection for 10 minutes or 1,500 kcts.
99mTc-MIBI semiquantitative analysis:
ROI drawn over the uptake area. Total counts divided into the number of pixels yielded a mean value per pixel (T). A similar ROI over background activity was B value.
Tumor-to-background uptake ratio (T/B) was calculated in all patients.
Early (5 minutes) and delayed (1 hour) (E/D) difference in uptake was calculated with the formula:
E/D=log n early T/B - log n delayed T/B
Histopathological study:
Tumor size.
Presence or absence of axillar lymph node metastases.
Histological Degree (Scarff Bloom Richardson).
Nuclear Degree.
Mitotic Index.
Cellular Atypia.
Oestrogen receptor expression.
Statistical Analysis: The significance of proportions was evaluated by Fisher´s exact test. Comparison of MIBI uptake with different prognostic factors was made with ANOVA test and mean comparisons with a t-Student test.
There are a statistically significant correlation with:
Mitotic index. The higher the mitotic index is, the higher the T/B ratio and the lower early/delayed difference (washout decreases).
Negative correlation with SCBR histological degree. The less differentiated the more intense the uptake is with higher T/B ratio and lower washout index.
| *p = 0.02 **p = 0.05 | Mitotic Index | Scarff Bloom Richardson grade | ||||||
| Low | Mild | High | I | II | III | |||
| Early lat T/B ratio* | 1.91 ± 0.4
| 2.15 ± 0.6 | 2.51 ± 0.9 | 2.08 ± 0.6 | 2.14 ± 0.5 | 2.33 ± 0.9 | ||
| Ant T/B ratio* | 1.61 ± 0.4 | 1.74 ± 0.4 | 2.05 ± 0.9 | 1.68 ± 0.3 | 1.69 ± 0.5 | 1.99 ± 0.02 | ||
| D T/B ratio* | 1.66 ± 0.5 | 1.88 ± 0.4 | 2.45 ± 0.9 | 1.64 ± 0.5 | 1.87 ± 0.6 | 2.29 ± 0.9 | ||
| E/D ** | 0.14 ± 0.2 | 0.06 ± 0.1 | 0.09 ± 0.09 | 0.19 ± 0.2 | 0.09 ± 0.1 | 0.02 ± 0.09 | ||
MIBI-Tc99m uptake in breast carcinoma significantly correlates with differentiation degree: The less differentiated the higher uptake.
We found no correlation with the main histological parameters that define tumoral aggressiveness (tumor size, oestrogen receptor expression or axillar lymph node metastases).
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[Oncology] |
[Radiology & Nuclear Medicine] |
