The imaging sensitivity of PEM was higher than that of WBPET in Japanese women younger than 50 years. Positron emission mammography showed significant sensitivity in tumors smaller than 1 cm, which has been a weak point for WBPET.

PurposeTo validate semiquantitative analysis of positron emission mammography (PEM).MethodsFifty women with histologically confirmed breast lesions were retrospectively enrolled. Semiquantitative uptake values (4 methods), the maximum PEM uptake value (PUVmax), and the lesion-to-background (LTB) value (3 methods) were measured. LTB is a ratio of the lesion’s PUVmax to the mean background; LTB1, LTB2, and LTB3 (which were calculated on different background) were used to designate the three values measured. Interobserver reliability between two readers for PUVmax and the LTBs was tested using the interobserver correlation coefficient (ICC). The likelihood ratio test was used to evaluate the relationship between ICCs. Receiver operating characteristic (ROC) curves were calculated for all methods. Diagnostic accuracy in differentiating benign tissue from malignant tissue was compared between PUVmax and LTB1.ResultsThe ICC rate was 0.971 [95 % confidence interval (CI) 0.943–0.986] for PUVmax, 0.873 (95 % CI 0.758–0.935) for LTB1, 0.965 (95 % CI 0.925–0.983) for LTB2, and 0.895 (95 % CI 0.799–0.946) for LTB3. However, there were some technical difficulties in the practical use of LTB2 and LTB3. The likelihood ratio test between PUVmax and LTB1 was statistically significant (p < 0.001). ROC curves of the 4 methods had similar characteristics. The median PUVmax was 1.39 for benign lesions and 3.70 for malignant lesions. LTB1 was 1.92 for benign lesions and 4.78 for malignant lesions. Significant differences (p < 0.001) in both PUVmax and LTB1 were observed between groups.ConclusionDue to its simplicity and reproducibility, PUVmax is superior to LTB as an indicator for PEM in semiquantitative analysis.

Background Radiation-induced sarcoma (RIS) has a 10-year incidence of 0.2–0.27% and a poor prognosis. In particular, radiation-induced fibrosarcoma has been rarer, and its incidence is 2.6–3.7% of RIS. Case presentation: A 43-year-old woman with pT1N1M0 breast cancer underwent breast-conserving surgery, chemotherapy, radiation therapy eight years ago, and continued hormonal therapy. She complained of a hard mass palpated in her right axillary breast. Although we suspected local recurrence, core needle biopsy revealed atypical spindled tumor cells without mammary or epithelial markers. A diagnosis of fibrosarcoma was made via tumorectomy. She underwent additional enlarged surgery. Conclusions We report a rare case of fibrosarcoma after breast-conserving surgery and radiation therapy. Fibrosarcoma after radiation therapy for breast cancer has been reported in 30 cases, including the present case. The dead and alive cases were not significantly different in terms of age, primary breast cancer, radiation dose, and following months. Patients with breast masses after radiation therapy should be suspected local recurrence and RIS.

Background: Radiation-induced sarcoma (RIS) has a 10-year incidence of 0.2-0.27% and a poor prognosis. In particular, radiation-induced fibrosarcoma has been rarer, and its incidence is 2.6-3.7% of RIS.Case presentation: A 43-year-old woman with pT1N1M0 breast cancer underwent breast-conserving surgery, chemotherapy, radiation therapy eight years ago, and continued hormonal therapy. She complained of a hard mass palpated in her right axillary breast. Although we suspected local recurrence, core needle biopsy revealed atypical spindled tumor cells without mammary or epithelial markers. A diagnosis of fibrosarcoma was made via tumorectomy. She underwent additional enlarged surgery.Conclusions: We report a rare case of fibrosarcoma after breast-conserving surgery and radiation therapy. Fibrosarcoma after radiation therapy for breast cancer has been reported in 30 cases, including the present case. The dead and alive cases were not significantly different in terms of age, primary breast cancer, radiation dose, and following months. Patients with breast masses after radiation therapy should be suspected local recurrence and RIS.

Background: Radiation-induced sarcoma (RIS) has a 10-year incidence of 0.2-0.27% and a poor prognosis. In particular, radiation-induced fibrosarcoma has been rarer, and its incidence is 2.6-3.7% of RIS.Case presentation: A 43-year-old woman with pT1N1M0 breast cancer underwent breast-conserving surgery, chemotherapy, radiation therapy eight years ago, and continued hormonal therapy. She complained of a hard mass palpated in her right axillary breast. Although we suspected local recurrence, core needle biopsy revealed atypical spindled tumor cells without mammary or epithelial markers. A diagnosis of fibrosarcoma was made via tumorectomy. She underwent additional enlarged surgery.Conclusions: We report a rare case of fibrosarcoma after breast-conserving surgery and radiation therapy. Fibrosarcoma after radiation therapy for breast cancer has been reported in 30 cases, including the present case. The dead and alive cases were not significantly different in terms of age, primary breast cancer, radiation dose, and following months. Patients with breast masses after radiation therapy should be suspected local recurrence and RIS.