Breast-specific gamma imaging as an adjunct modality for the diagnosis of invasive breast cancer with correlation to tumour size and grade

Abstract

Objectives: The purpose of this study was to determine the sensitivity of breastspecific gamma imaging (BSGI) in the detection of invasive breast cancers and to characterise the sensitivity of BSGI based on tumour size and pathological grade. Methods: 139 females with invasive carcinoma who underwent BSGI were retrospectively reviewed. Patients were injected in the antecubital vein with 20-30 mCi (925-1110 MBq) of 99m Tc-sestamibi. Images were obtained with a high-resolution, breast-specific gamma camera (Dilon 6800; Dilon Technologies, Newport News, VA) and were categorised based on radiotracer uptake as normal, normal with heterogeneous uptake, probably abnormal and abnormal. For a positive examination, the region of the area of increased uptake had to correlate with the laterality and location of the biopsy-proven cancer. Results: 149 invasive cancers in 139 patients with a mean size of 1.8 cm (0.2-8.5 cm) were included. 146 were identified with BSGI (98.0%). All cancers which measured $0.7 cm (n5123) as well as all cancers grade 2 or higher (n5102), regardless of tumour size, were identified with BSGI (100%). There were 6 cancers that were pathological grade 1 and measured ,7 mm, of which 50% (3/6) were identified with BSGI. The overall sensitivity of BSGI for the detection of invasive breast cancer is 98.0%. The sensitivity for subcentimetre cancers is 88.5% (23/26). Conclusion: BSGI has a high sensitivity for the detection of invasive breast cancer. Our results demonstrate that BSGI detected all invasive breast cancers pathological grade 2 and higher regardless of size and all cancers which measured $7 mm regardless of grade. BSGI can reliably detect invasive breast cancers and is a useful adjunct imaging modality for the diagnosis of breast cancer. Mammography has remained the modality of choice for breast cancer screening. Nevertheless, it is an imperfect examination with a sensitivity of 78-85% that declines to 68% in females with dense breasts [1][2][3][4][5][6]. The limitations of mammography have resulted in the development of adjunct imaging modalities to improve breast cancer detection. Most frequently, ultrasound is used in conjunction with mammography as an adjunct imaging modality for breast cancer diagnosis, particularly in females with dense breasts [2].Mammography and ultrasound are both anatomical approaches for the diagnosis of breast cancer. Nuclear medicine techniques that utilise physiological properties of tumours are increasingly being used. A meta-analysis of scintimammographic studies using a traditional, general purpose gamma camera demonstrated an average sensitivity of 84% for breast cancer detection, although many of the cancers included in these studies were palpable and larger [7]. However, scintimammography with a general purpose gamma camera is limited in the detection of non-palpable cancers and cancers less than 1 cm in size because of intrinsic resolution limitations [8][9][10][11]. Another limitation is the inability of a general purpose gamma camera to image in positions...

The Impact of Tumor Size in Breast Needle Biopsy Material on Final Pathologic Size and Tumor Stage

“…1 In addition to the ability to predict a potentially insignificant disease that could be managed by active surveillance, 2 tumor extent on prostate needle biopsy has been found to correlate well with tumor volume on radical prostatectomy 3-7 and helps predict margin status, 8 extraprostatic extension, 9,10 and, in combination with other parameters, posttreatment tumor progression. [11][12][13][14][15] There are several studies of mammary carcinoma that have examined the relationship between radiologic tumor size and the subsequent size on final excision [16][17][18][19][20][21] as well as those that have evaluated the relationship between radiologic or pathologic tumor size (on excision) and the likelihood of lymph node metastasis. [22][23][24][25][26] To the best of our knowledge, however, there are no systematic studies that evaluate the relationship between tumor size/extent on breast needle biopsy specimens and corresponding definitive excision specimens.…”

Breast cancer screening controversies: who, when, why, and how?

“…In this study, 139 females with known invasive carcinoma and an average tumor size of 1.8 cm underwent scintimammography. Of the known 149 cancers, 146 were identified with breast-specific gamma imaging, resulting in an overall sensitivity of 98% [70].…”

Prognostic value of semi-quantitative tumor uptake on Tc-99m sestamibi breast-specific gamma imaging in invasive ductal breast cancer

“…The primary inclusion criteria were: (1) pathologically confirmed invasive ductal carcinoma; (2) absence of distant metastasis; (3) absence of neoadjuvant chemotherapy or radiotherapy before BSGI; and (4) pathologic tumor size C1 cm to avoid any partial volume effect. Despite the use of high-resolution equipment, the small-fieldof-view of the breast-specific gamma camera and the small tumor size still remain as limitations [7]. Retrospective review of our database between March 2009 and September 2012 yielded 168 eligible patients.…”

“…Biological information on breast cancer is important for predicting prognosis and is mainly estimated by pathologic procedures. A few studies have reported a correlation between Tc-99m sestamibi uptake and histologic prognostic factors of breast cancer [7,8]. The prognostic value of Tc-99m sestamibi washout rate from breast cancer cells for predicting responses to neoadjuvant chemotherapy has been investigated based on its relationship with P-glycoprotein (Pgp) expression [9].…”