Indications and Role of 2-[18F]FDG PET/CT in Breast Cancer Staging and Management
2-[18F]FDG PET/CT is a diagnostic imaging technique used for staging and managing breast cancer patients. Its indications and role vary depending on the stage of the disease.
Stage IIB:
2-[18F]FDG PET/CT is recommended for staging of stage IIB breast cancer.
It can be used as an alternative to conventional imaging modalities for staging, without the need for additional tests.
It has been shown to identify more extensive disease, including nodal and distant metastases, with high detection rates and comparable cost.
Stage IIIA-IIIC:
2-[18F]FDG PET/CT is recommended for staging of stage IIIA-IIIC breast cancer.
It is also recommended for staging of inflammatory breast cancer.
It can replace separate conventional imaging modalities for staging.
2-[18F]FDG PET/CT is useful in improving radiation therapy planning and may be used to assess early metabolic response to treatment.
Stage IV:
2-[18F]FDG PET/CT plays a crucial role in detecting metastases when conventional imaging methods are inconclusive.
It is recommended for patients with symptoms suggestive of metastatic disease or rising tumor markers.
It can guide the site of biopsy and improve radiation therapy planning.
2-[18F]FDG PET/CT is a suitable substitute for CT and/or bone scan in evaluating bone lesions.
It may be used to monitor treatment response in metastatic breast cancer.
The use of 2-[18F]FDG PET/CT has been supported by various studies and meta-analyses, demonstrating its effectiveness in identifying distant metastases, improving staging accuracy, and guiding treatment decisions. The recommendations provided are based on the level of evidence and agreement among experts in the field. The technique offers advantages such as higher sensitivity and specificity, convenience, and the potential for early detection of treatment response.
Indications for 2-[18F]FDG PET/CT
2-[18F]FDG PET/CT is a diagnostic procedure used in certain stages of breast cancer to aid in staging, clinical management, therapy assessment, and treatment planning. The indications for 2-[18F]FDG PET/CT can be categorized into three stages: Stage IIB, Stage IIIA-IIIC, and Stage IV.
Stage IIB:
2-[18F]FDG PET/CT is recommended for staging of stage IIB non-small cell breast cancer (NST) with a high level of evidence and agreement.
2-[18F]FDG PET/CT can be used as an alternative to conventional imaging modalities for NST breast cancer staging, rather than in combination with them.
The role of 2-[18F]FDG PET/CT in staging includes:
Identifying distant metastases in patients with clinical stage ≥ IIB BC.
Detecting more extensive disease, including nodal and distant metastases, compared to conventional imaging.
Assisting in the evaluation of lymph node regions that are not easily accessible by ultrasound, such as internal mammary and mediastinal lymph nodes.
Stage IIIA-IIIC:
2-[18F]FDG PET/CT is recommended for staging of stage IIIA-IIIC breast cancer with a high level of evidence and agreement.
2-[18F]FDG PET/CT is also recommended for staging of inflammatory breast cancer.
It can replace separate conventional imaging modalities for staging and is useful in improving radiotherapy (RT) planning.
2-[18F]FDG PET/CT may be used to assess early metabolic response to treatment.
In staging:
2-[18F]FDG PET/CT is recommended for initial staging in high-risk primary breast cancer to improve treatment planning.
It can identify extra-axillary regional lymph nodes and distant metastases in patients with clinical T3N0, T2N1, or T3N1 disease.
Inflammatory breast cancer staging benefits from improved nodal staging and higher accuracy in detecting distant metastases compared to conventional imaging.
In treatment planning:
2-[18F]FDG PET/CT is valuable in identifying distant metastases and nodal disease outside conventional RT fields, leading to changes in RT plans.
It aids in regional RT planning and improves the treatment strategy for inflammatory breast cancer.
In assessing treatment response:
2-[18F]FDG PET/CT can predict early histopathological response to neoadjuvant therapy and detect metabolic changes after systemic therapy.
It plays a potential role in evaluating metabolic response during neoadjuvant therapy and post-treatment to assess disease-free and overall survival.
The combination of 2-[18F]FDG PET/CT and other modalities can improve the diagnostic performance in assessing treatment response.
In patients with suspected recurrent disease or rising tumor markers, 2-[18F]FDG PET/CT can change clinical management and guide the site of biopsy.
It aids in monitoring treatment response in metastatic breast cancer, especially in cases of multiple distant metastases and bone metastases.
Stage IV:
2-[18F]FDG PET/CT is useful in detecting the site and extent of metastasis when conventional imaging methods provide equivocal results.
It is recommended in patients with signs or symptoms suggestive of metastatic disease and rising serum tumor markers.
2-[18F]FDG PET/CT aids in guiding the site of biopsy, improving RT planning, and substituting for CT and/or bone scan in bone lesion evaluation.
It may also play a role in monitoring treatment response in metastatic breast cancer.
Overall, 2-[18F]FDG PET/CT is a valuable tool in breast cancer management, providing accurate staging, treatment planning, and assessment of treatment response, particularly in specific stages and clinical situations.
Breast cancer: initial workup and staging with FDG PET/CT
https://link.springer.com/article/10.1007/s40336-021-00426-z:
FDG-PET/CT is useful for the initial staging of breast cancer, independently of tumor phenotype (triple negative, luminal or HER2 +) and regardless of tumor grade. Considering histological subtype, FDG-PET/CT performs better for staging invasive ductal carcinoma (invasive carcinoma of no specific subtype), although it is also helpful for staging invasive lobular carcinomas.
Based on the available data, FDG-PET/CT becomes useful for staging starting from clinical-stage IIB. FDG-PET/CT is possibly useful in patients with clinical stage IIA (T1N1 or T2N0), but there is not enough strong data to recommend routine use in this subgroup (here we can make a point for Triple Negative BC). For clinical stage I (T1N0) patients, staging with FDG-PET/CT offers no added value.
These findings justify the following recommendations:
1. FDG-PET/CT is recommended for initial staging in patients with clinical stage ≥ IIB breast cancer and is better when performed before surgery.
2. FDG-PET/CT can be proposed for staging patients with clinical stage IIA (T1N1 or T2N0) breast cancer and is better when performed before surgery.
3. FDG-PET/CT is not recommended for staging patients with clinical stage I (T1N0) breast cancer.