Pretreatment Scanning May Predict IDC Overall Survival

Metabolic tumor volume (MTV), determined by FDG PET/CT performed before treatment for invasive ductal carcinoma of the breast (IDC) can predict overall survival, according to a study published in the American Journal of Roentgenology.

Researchers from Korea sought to evaluate the prognostic relevance of PET parameter measured by 18F-FDG PET/CT in patients with IDC the breast who had distant metastasis at the time of initial diagnosis.

The retrospective study included 40 women with IDC, ranging from ages 29 to 75, who had had distant metastasis at the time of initial diagnosis. All had undergone FDG PET/CT before receiving treatment. They also underwent mammography, sonography, bone scan, breast MRI, and conventional contrast-enhanced CT (in the region of metastases) for pretreatment clinical staging.

Treatment for all patients was systemic chemotherapy, hormone therapy, or both as first-line treatment. Thirty-one patients also underwent radiation therapy concurrently with systemic chemotherapy or hormone therapy. In addition, 17 patients with ERBB2–positive breast cancer received trastuzumab, and 15 patients underwent palliative surgery as second-line treatment.

The researchers examined clinicopathologic parameters and metabolic PET parameters, including the maximum standardized uptake value (SUVmax) of the primary tumor (pSUVmax), the SUVmax of the axillary lymph node (nSUVmax), the highest SUVmax of whole malignant lesions (wSUVmax), the whole-body (WB) metabolic tumor volume (MTV), and WB total lesion glycolysis (TLG).

Twenty-one of the 40 patients (52.5%) died during follow-up (mean follow-up, 36.4 months; range, 0.8–71.4 months). “Nonsurvivors had a statistically significantly higher mean (± SD) WB MTV than did survivors (424.0 ± 683.9 versus 92.1 ± 96.3 cm3; p = 0.0430),” the authors wrote.

The researchers concluded that pretreatment FDG PET/CT could determine the WB MTV value, which was found to be an independent prognostic factor for overall survival in patients with IDC who had distant metastasis at the time of initial diagnosis.