Impacto diagnóstico y terapéutico de la 18F-FDG-PET/TAC en pacientes con sospecha de recidiva de cáncer de mama

18F-FDG PET/CT in the Staging and Management of Breast Cancer: Value in Disease Outcome and Planning Therapy

In hormone receptor-positive locally advanced breast cancer, endocrine therapy becomes an integral part of the therapeutic strategy. There are now significant numbers of available hormonal directed compounds, including selective aromatase and mTOR inhibitors, which allow an important therapeutic advance in these patients. Sequential F-FDG PET/CT studies provided essential information regarding response to different treatments, including targeted therapies, and adverse therapeutic effects that helped to better define the right moment to implement each therapeutic approach.

18F-FDG semi-quantitative parameters and biological prognostic factors in locally advanced breast cancer

AIM

To analyse the correlation between (18)F-FDG uptake assessed by PET/CT in locally advanced breast tumours and histopathological and immunohistochemical prognostic factors.

MATERIAL AND METHODS

Thirty-six women with breast cancer were prospectively evaluated. PET/CT was requested in the initial staging previous to adjuvant chemotherapy (multicentric study). All the patients underwent an (18)F-FDG PET/CT with a dual-time-point acquisition. Both examinations were evaluated qualitatively and semiquantitatively with calculation of SUVmax values in PET-1 (SUV-1) and in PET-2 (SUV-2) and the percentage variation of the standard uptake values (retention index) between PET-1 and PET-2. Clinical and metabolic stages were assessed according to TNM classification. The biological prognostic parameters, such as the steroid receptor status, p53 and c-erbB-2 expression, proliferation rate (Ki-67), and grading were determined from tissue of the primary tumour. Metabolic and biological parameters were correlated.

RESULTS

A positive relationship was found between semiquantitative metabolic parameters and biological parameters. SUV-1 and SUV-2 values did not show significant statistical correlation (p<.05) except for the clinical tumour size. About the biological parameters, retention index showed the best results with positive and significant relation (p<.05) with estrogen and progesterone receptor status and Ki-67. Isolated SUV values did not show significant relation to these parameters.

CONCLUSION

Retention index showed the best relation with biological parameters compared to isolated SUVmax values. These data suggest that SUV change over time is a prognostic marker.

Primary epithelioid trophoblastic tumor with a synchronous breast carcinoma detected only with FDG-PET/CT Scan

Epithelioid trophoblastic tumor is a recently described, rare and distinctive type of gestational trophoblastic tumor. We report the case of a 31-year old patient who had a full-term pregnancy 18 months before presentation. She had a right axillary lymph node metastasis and was referred for FDG-PET/CT scan for evaluation of distant metastasis and to detect primary malignancy. The axillary lymph node biopsy revealed metastatic breast carcinoma. FDG-PET/CT revealed increased uptake of right axillary lymph node, soft tissue density lesion with a diameter of 24 mm on left cervical region with increased FDG uptake, increased uptake on cervical region and left inguinal lymph node with increased uptake. Pelvic MRI imaging and ultrasonography were negative for malignancy in cervical region. Biopsy of the lesion was consistent with epithelioid trophoblastic tumor in cervical region. Gestational trophoblastic tumor was not suspected because she had no signs such as abnormal vaginal bleeding. FDG-PET/CT demonstrated the primary lesion in cervical region. We report a rare case of primary epithelioid trophoblastic tumor detected only with FDG-PET/CT scan which synchronized with breast carcinoma.