Elsevier

Clinical Imaging

Volume 39, Issue 3, May–June 2015, Pages 506-509
Clinical Imaging

Case Report
Prone 18F-FDG PET/CT changes diagnostic and surgical intervention in a breast cancer patient: some considerations about PET/CT imaging acquisition protocol

https://doi.org/10.1016/j.clinimag.2014.11.005Get rights and content

Abstract

We report a case study demonstrating the value of prone positioning in positron emission tomography (PET) of a woman with diagnosed breast cancer (BC) addressed to lumpectomy. Surgeon required 18F-fluorodeoxiglucose (18F-FDG) PET study for staging and assessment of lymphnode involvement/metastasis prior to lumpectomy: a whole-body supine study and a prone acquisition of breast. Supine study revealed one lesion, while prone study revealed two lesions. Prone PET findings changed diagnosis and therapeutic intervention for patient who was subsequently subjected to quadrantectomy.

Introduction

The diagnosis of breast cancer (BC) is performed with the support of a multimodal imaging approach, including X-ray mammography and ultrasound [1]. A preoperative diagnosis can be confirmed by cytology and histology. The staging of BC is completed by the evaluation of lymph nodes and distant metastases using other imaging methods including 18 F-fluorodeoxiglucose (18F-FDG) positron emission tomography (PET) combined with computed tomography (CT) (18F-FDG PET/CT) and magnetic resonance imaging (MRI) [2], [3], [4].

The role of 18F-FDG PET/CT as a staging procedure in primary BC is not completely established, although promising results have been reported [5], [6]. Many 18F-FDG PET/CT studies have been performed in large and/or locally advanced BC, and lower PET sensitivities have been reported for small and node-negative BC [5], [7], [8], mainly due to the partial volume effect (PVC) [9]. Recent studies have shown the prognostic role of 18F-FDG PET/CT in BC when accurate semiquantification of 18F-FDG uptake within the lesion is provided [10]. Clinical guidelines for BC patients have recommended the use of PET/CT as an additional examination tool when standard staging examinations are equivocal or suspicious [11].

Standard 18F-FDG PET/CT imaging protocols for BC staging are based on whole-body studies with the patient in supine position [4]. However, some studies have suggested that PET acquisition with the patient in prone position can provide better visualization of the uptaking lesions in comparison with the standard supine procedure [12]. To our knowledge, the value of prone positioning in 18F-FDG PET-CT in the management of BC patients for both the diagnosis and development of a therapeutic intervention has not been proven, and PET whole-body studies with the patient in supine position still comprise the adopted acquisition procedure for both the staging of breast primary tumors and the assessment of lymph nodes and distant metastases.

Here, we report a case study of a patient with newly diagnosed BC and who was a candidate for a lumpectomy; her diagnostic and surgical program changed following new findings that were obtained from an 18F-FDG PET/CT presurgical evaluation with the patient in prone position. These findings allow important considerations to be derived regarding the optimal PET/CT imaging acquisition protocol in BC patients.

Section snippets

Patient management

A 57-year-old woman went to San Raffaele Hospital (OSR), Milan, Italy, after BC was discovered via mammography, ultrasound, and fine-needle aspiration cytology (FNAC) at another hospital. In the upper outer quadrant of the left breast, mammography and ultrasound showed a small, irregular mass in the axillary tail, and medially, an oval hypoechoic nodule in the prepectoral region was also found. FNAC on the first finding revealed an invasive ductal carcinoma, while indicated fibroadenoma for the

Results

In terms of lesion detectability, only one uptake lesion was detected by the 18F-FDG PET/CT images when the patient was in supine position (Fig. 1, Panel A) while two uptake lesions were visualized by the 18F-FDG PET/CT images when the patient was in prone position (Fig. 1, Panel B), thus revealing that one uptake lesion was confounded with the other lesion upon visual inspection. For both supine and prone 18F-FDG PET/CT images, no abnormal increase in glucose uptake was detected in the other

Discussion

There are several reasons for suggesting PET image acquisition when performing a breast study with the breast in a fixed and undeformed position [12], [18], [19]. First, it offers the possibility of avoiding potential deformities and compression of the mammary gland; it also limits chest wall movement. In addition, it offers excellent separation of the deep breast structures from the myocardium in the left breast, and the relaxation of the pectoralis muscle. All of these conditions can enhance

Conclusions

In conclusion, this case thus demonstrated that an 18F-FDG PET/CT study with the patient in prone position should be recommended when evaluating BC, as it allows for better detectability of both the breast and axilla regions. This method also plays a role in the diagnosis and surgical intervention development for BC patients.

Acknowledgments

English-language editing of this manuscript was provided by Journal Prep.

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