The Benefit of 18f-FDG PET/CT in Breast Cancer Patient Staging and Treatment Planning: A Case Report

Special Article – Breast Cancer- Risk Factors, Diagnosis and Treatment

Austin J Cancer Clin Res 2015;2(1): 1024.

The Benefit of 18f-FDG PET/CT in Breast Cancer Patient Staging and Treatment Planning: A Case Report

Valli M*, Belosi MF, Nicolini G and Richetti A

Radiation Oncology, Oncology Institute of Southern Switzerland, Switzerland

*Corresponding author: Valli M, Radiation Oncology Unit, Oncology Institute of Southern Switzerland, Via Ospedale, 6500 Bellinzona (CH), Switzerland.

Received: January 30, 2015; Accepted: February 18, 2015; Published: February 20, 2015


A 50 year old female patient was treated with left mastectomy plus axillary dissection for ductal infiltrating carcinoma mpT1c pN1(1/15) M0 in October 2009. The patient was staged post-operatively with 18F-FDG PET/CT and unexpected internal mammary chain lymph node metastases were detected. The patient received adjuvant chemo/hormonal therapy and radiotherapy on regional lymph nodes up to a dose of 50 Gy with a volume modulated arc (VMAT) technique, reaching a complete response. At 5 year follow-up the patient is still alive in complete response without radiotherapy late toxicity.

Keywords: 18F-FDG PET/CT; Breast cancer; Internal mammary chain; VMAT


The role of 18F-FDG PET/CT in the staging of breast cancer is still controversial. Its use in early stage cases is not recommended, whereas in locally advanced cases it can lead to a change in the staging phase from 6.7% to 52%and consequently to a change in the treatment approach from 5.6% to 56% of the cases [1,2].

18F-FDG PET/CT improves the diagnosis of undetected lymph node metastases outside the axilla (i.e. infraclavicular, supraclavicular and internal mammary nodes) or occult and asymptomatic distant metastases [3].

Case Presentation

A 50 year old female patient detected a lump in the inner-superior quadrant of left breast. Subsequent mammography, ultrasound and fine needle aspiration confirmed a ductal infiltrating carcinoma and she was treated with mastectomy, simultaneous reconstruction with prosthesis and contralateral mastoplasty. The final diagnosis confirmed a ductal infiltrating carcinoma ER95%, PR80%, Ki67 20%, c-erbB2 score 2 (FISH neg), lymphovascular invasion, mpT1c pN1(1/15) M0 associated to peritumoral DCIS G3 (5-10%). A postoperative 18F-FDG PET/CT was performed and the final stage was modified in pN3b due to the detection of metastases in the internal mammary chain lymph nodes (IMC LN). The diagnose was confirmed by a fine needle aspiration on the largest lymph node. Therefore the patient received 4 adjuvant chemotherapy cycles (AC schedule), LHRH analogues for 2 years, and aromatase inhibitors for 5 years and radiotherapy at the end of chemotherapy.

The radiotherapy treatment was performed with VMAT Rapid Arc (Varian Medical System, Palo Alto, California) from April 2010 until May 2010. The prescribed total dose was of 50 Gy, 5 fractions per week, 2 Gy each. The post-operative 18F-FDG PET/CT was merged with the planning CT. The contoured Clinical target Volume (CTV) included the supraclavicular/infraclavicular lymph nodes and the IMC. The chest wall was excluded due to fact that the tumor size was <2 cm and due to the presence of the prosthesis. The 18F-FDG PET/CT allowed a correct detection of the IMC LN, not visible on the planning CT (Figure 1). The Planning Target Volume (PTV) was obtained extending the CTV up to 0.8 cm and cropped 0.2 cm from the body surface. As Organs at Risk (OARs), the contralateral breast, the ipsilateral prosthesis, the lungs, the spine, the heart, the thyroid and the left anterior descending coronary artery (LAD), were considered. A dedicated structure was contoured for minimizing the dose spillage outside the PTV, named Healthy Tissue (HT). Such structure was drawn at 0.2 cm distance from the PTV and extended up to 2.0 cm. The treatment plan was designed on the Varian Eclipse Treatment Planning System (platform 8.6) for a Varian iX linear accelerator, 6 MV energy beam. Two partial arcs (CW and CCW) were applied in order to avoid beam entrances from the controlateral lung and controlateral breast. Inverse planning was performed by means of the Progressive Resolution Optimizer III, version 10.0.28, employing the intermediate dose options in order to increase the accuracy of optimization and the agreement between optimization and final dose calculation. Dose-volume constraints during the optimization were defined to match the planning goals of having more than 95% of the PTV volume receiving >95% of the prescribed dose (V95%>95%) and of minimizing the dose to the ipsilateral lung (V20Gy<20%), to the heart and the LAD. The obtained dosimetric parameters are listed in Table 1. The patient concluded the scheduled treatment. Orthogonal X-Ray imaging was performed every day for a correct patient set-up.