The uptake of ¹⁸F-fluorothymidine (¹⁸F-FLT) depends on cells’ proliferative rates. We compared the characteristics of ¹⁸F-FLT positron emission tomography/computed tomography (PET/CT) with those of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT for breast cancer. We prospectively diagnosed patients with breast cancer who underwent ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT. Subsequently, significant differences and correlation coefficients of the maximum standardized uptake value (SUVmax) in primary breast cancer and axillary lymph nodes were statistically evaluated. We enrolled eight patients with breast cancer. In six treatment-naive patients, the SUVmax for primary lesions showed a significant difference (mean, 2.1 vs. 4.1, p = 0.031) and a strong correlation (r = 0.969) between ¹⁸F-FLT and ¹⁸F-FDG. Further, although the SUVmax for the axillary lymph nodes did not show a significant difference between ¹⁸F-FLT and ¹⁸F-FDG (P = 0.246), there was a strong correlation between the two (r = 0.999). In a patient-by-patient study, there were cases in which only ¹⁸F-FDG uptake was observed in lymph nodes and normal breasts. Bone metastases demonstrated lower accumulation than bone marrow on the ¹⁸F-FLT PET/CT. In conclusion, a strong correlation was observed between the ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT uptake. Differences in the biochemical characteristics of ¹⁸F-FLT and ¹⁸F-FDG were reflected in the accumulation differences for breast cancer, metastatic lesions, and normal organs.

We investigated whether ¹⁸F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography images restored via deep learning (DL) improved image quality and affected axillary lymph node (ALN) metastasis diagnosis in patients with breast cancer. Using a five-point scale, two readers compared the image quality of DL-PET and conventional PET (cPET) in 53 consecutive patients from September 2020 to October 2021. Visually analyzed ipsilateral ALNs were rated on a three-point scale. The standard uptake values SUV_max and SUV_peak were calculated for breast cancer regions of interest. For “depiction of primary lesion”, reader 2 scored DL-PET significantly higher than cPET. For “noise”, “clarity of mammary gland”, and “overall image quality”, both readers scored DL-PET significantly higher than cPET. The SUV_max and SUV_peak for primary lesions and normal breasts were significantly higher in DL-PET than in cPET (p < 0.001). Considering the ALN metastasis scores 1 and 2 as negative and 3 as positive, the McNemar test revealed no significant difference between cPET and DL-PET scores for either reader (p = 0.250, 0.625). DL-PET improved visual image quality for breast cancer compared with cPET. SUV_max and SUV_peak were significantly higher in DL-PET than in cPET. DL-PET and cPET exhibited comparable diagnostic abilities for ALN metastasis.

Although several studies have been conducted on artificial intelligence (AI) use in mammography (MG), there is still a paucity of research on the diagnosis of metachronous bilateral breast cancer (BC), which is typically more challenging to diagnose. This study aimed to determine whether AI could enhance BC detection, achieving earlier or more accurate diagnoses than radiologists in cases of metachronous contralateral BC. We included patients who underwent unilateral BC surgery and subsequently developed contralateral BC. This retrospective study evaluated the AI-supported MG diagnostic system called FxMammo™. We evaluated the capability of FxMammo™ (FathomX Pte Ltd., Singapore) to diagnose BC more accurately or earlier than radiologists’ assessments. This evaluation was supplemented by reviewing MG readings made by radiologists. Out of 1101 patients who underwent surgery, 10 who had initially undergone a partial mastectomy and later developed contralateral BC were analyzed. The AI system identified malignancies in six cases (60%), while radiologists identified five cases (50%). Notably, two cases (20%) were diagnosed solely by the AI system. Additionally, for these cases, the AI system had identified malignancies a year before the conventional diagnosis. This study highlights the AI system’s effectiveness in diagnosing metachronous contralateral BC via MG. In some cases, the AI system consistently diagnosed cancer earlier than radiological assessments.

Background: High breast density found using mammographs (MGs) reduces positivity rates and is considered a risk factor for breast cancer. Research on the relationship between Volpara density grade (VDG) and compressed breast thickness (CBT) in the Japanese population is still lacking. Moreover, little attention has been paid to pseudo-dense breasts with CBT < 30 mm among high-density breasts. We investigated VDG, CBT, and apparent high breast density in patients with breast cancer. Methods: Women who underwent MG and breast cancer surgery at our institution were included. VDG and CBT were measured. VDG was divided into a non-dense group (NDG) and a dense group (DG). Results: This study included 419 patients. VDG was negatively correlated with CBT. The DG included younger patients with lower body mass index (BMI) and thinner CBT. In the DG, patients with CBT < 30 mm had lower BMI and higher VDG; however, no significant difference was noted in the positivity rate of the two groups. Conclusions: Younger women tend to have higher breast density, resulting in thinner CBT, which may pose challenges in detecting breast cancer on MGs. However, there was no significant difference in the breast cancer detection rate between CBT < 30 mm and CBT ≥ 30 mm.

Background and objectives: Our department has been performing primary breast reconstruction for breast cancer surgery, incorporating a transverse rectus abdominis myocutaneous flap (TRAM)/vertical rectus abdominis myocutaneous flap (VRAM) since 1998 and a deep inferior epigastric artery perforator flap (DIEP) since 2008. Currently, most gastrointestinal operations in abdominal surgery are performed laparoscopically or are robot-assisted. Cases in which abdominal surgery was performed after breast reconstruction using an abdominal flap were reviewed. Method: A total of 119 cases of primary breast reconstruction using an abdominal flap performed in our department were reviewed. Result: The reconstructive techniques were DIEP in 69 cases and TRAM/VRAM in 50 cases. After breast surgery, seven abdominal operations were performed in six cases. In DIEP cases, one robotic surgery was performed for uterine cancer, and one laparoscopic surgery was performed for ovarian tumor. In TRAM/VRAM cases, two laparoscopic cholecystectomies, one laparoscopic total gastrectomy, one laparoscopic ileus reduction, and one open total hysterectomy oophorectomy were performed. Six surgeries were completed by laparoscopy or robotic assistance. Conclusion: The survival rate after breast cancer surgery is improving, and the choice of breast reconstruction procedure should take into account the possibility of performing a prophylactic resection of the ovaries due to the genetic background and possibly postoperative abdominal surgery due to other diseases. However, in cases in which laparoscopic surgery was attempted after breast reconstruction using an abdominal flap, the laparoscopic surgery could be completed in all cases.

A woman in her 70s was diagnosed with left breast cancer and left axillary lymph node metastasis by an ultrasound-guided biopsy. ¹⁸F-FDG-PET/CT showed strong FDG accumulation in the tumor in the left breast and a left axillary lymph node. Neoadjuvant chemotherapy (NAC) was administered in combination with a G-CSF injection to prevent febrile neutropenia. The post-treatment ¹⁸F-FDG-PET/CT showed the disappearance of the left breast tumor and left axillary lymph node and revealed a solitary new area of strong FDG accumulation in the sternum. To rule out the possibility of sternal metastasis, a sternal biopsy was performed at the same time as surgery, which revealed no malignant findings. Although very rare, focal uptake on ¹⁸F-FDG-PET/CT performed after anticancer drug therapy with G-CSF may mimic a solitary bone metastasis. A bone biopsy may be a useful technique to avoid an immediate misdiagnosis of bone metastasis.