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Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

ABSTRACT: BACKGROUND:Molecular breast imaging (MBI) performed with 99mTc sestamibi has been shown to be a valuable technique for the detection of breast cancer. Alternative radiotracers such as 99mTc maraciclatide may offer improved uptake in breast lesions. The purpose of this study was to compare relative performance of 99mTc sestamibi and 99mTc maraciclatide in patients with suspected breast cancer, using a high-resolution dedicated gamma camera for MBI. Women with breast lesions suspicious for malignancy were recruited to undergo two MBI examinations-one with 99mTc sestamibi and one with 99mTc maraciclatide. A radiologist interpreted MBI studies in a randomized, blinded fashion to assign an assessment score (1-5) and measured lesion size. Lesion-to-background (L/B) ratio was measured with region-of-interest analysis. RESULTS:Among 39 analyzable patients, 21 malignant tumors were identified in 21 patients. Eighteen of 21 tumors (86%) were seen on 99mTc sestamibi MBI and 19 of 21 (90%) were seen on 99mTc maraciclatide MBI (p?=?1). Tumor extent measured with both radiopharmaceuticals correlated strongly with pathologic size (99mTc sestamibi, r?=?0.84; 99mTc maraciclatide, r?=?0.81). The L/B ratio in detected breast cancers was similar for the two radiopharmaceuticals: 1.55?±?0.36 (mean?±?S.D.) for 99mTc sestamibi and 1.62?±?0.37 (mean?±?S.D.) for 99mTc maraciclatide (p?=?0.53). No correlation was found between the L/B ratio and molecular subtype for 99mTc sestamibi (r s ?=?0.12, p?=?0.63) or 99mTc maraciclatide (r s ?=?-0.12, p?=?0.64). Of 20 benign lesions, 10 (50%) were seen on 99mTc sestamibi and 9 of 20 (45%) were seen on 99mTc maraciclatide images (p?=?0.1). The average L/B ratio for benign lesions was 1.34?±0.40 (mean?±S.D.) for 99mTc sestamibi and 1.41?±0.52 (mean?±S.D.) for 99mTc maraciclatide (p?=?0.75). Overall diagnostic performance was similar for both radiopharmaceuticals. AUC from ROC analysis was 0.83 for 99mTc sestamibi and 0.87 for 99mTc maraciclatide (p?=?0.64). CONCLUSIONS:99mTc maraciclatide offered comparable lesion uptake to 99mTc sestamibi, in both malignant and benign lesions. There was good correlation between lesion extent and uptake measured from both radiopharmaceuticals. 99mTc maraciclatide offered a marginal (but not significant) improvement in sensitivity over 99mTc sestamibi. Our findings did not support an association between the uptake of either radiopharmaceutical and tumor molecular subtype. TRIAL REGISTRATION:ClinicalTrials.gov, NCT00888589.

SUBMITTER: O'Connor MK

PROVIDER: S-EPMC5237435 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature

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Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

O'Connor Michael K MK Morrow Melissa M B MMB Hunt Katie N KN Boughey Judy C JC Wahner-Roedler Dietlind L DL Conners Amy Lynn AL Rhodes Deborah J DJ Hruska Carrie B CB

EJNMMI research 20170114 1

<h4>Background</h4>Molecular breast imaging (MBI) performed with <sup>99m</sup>Tc sestamibi has been shown to be a valuable technique for the detection of breast cancer. Alternative radiotracers such as <sup>99m</sup>Tc maraciclatide may offer improved uptake in breast lesions. The purpose of this study was to compare relative performance of <sup>99m</sup>Tc sestamibi and <sup>99m</sup>Tc maraciclatide in patients with suspected breast cancer, using a high-resolution dedicated gamma camera for M ...[more]

PMID: 28091980

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Project description:The determination of tumor human epidermal growth factor receptor type 2 (HER2) status is of increasing importance with the recent approval of more efficacious HER2-targeted treatments. There is a lack of suitable methods for clinical in vivo HER2 expression assessment. Affibody molecules are small affinity proteins ideal for imaging detection of receptors, which are engineered using a small (molecular weight 6.5 kDa) nonimmunoglobulin scaffold. Labeling of Affibody molecules with positron emitters enabled the development of sensitive and specific agents for molecular imaging. The development of probes for SPECT would permit the use of Affibody-based imaging in regions where PET is not available. In this first-in-human study, we evaluated the safety, biodistribution, and dosimetry of the 99mTc-ZHER2:41071 Affibody molecule developed for SPECT/CT imaging of HER2 expression. Methods: Thirty-one patients with primary breast cancer were enrolled and divided into three cohorts (injected with 500, 1000, or 1500 µg ZHER2:41071) comprising at least five patients with high (positive) HER2 tumor expression (IHC score 3+ or 2+ and ISH positive) and five patients with low (IHC score 2+ or 1+ and ISH negative) or absent HER2 tumor expression. Patients were injected with 451 ± 71 MBq 99mTc-ZHER2:4107. Planar scintigraphy was performed after 2, 4, 6 and 24 h, and SPECT/CT imaging followed planar imaging 2, 4 and 6 h after injection. Results: Injections of 99mTc-ZHER2:41071 were well tolerated and not associated with adverse events. Normal organs with the highest accumulation were the kidney and liver. The effective dose was 0.019 ± 0.004 mSv/MBq. Injection of 1000 µg provided the best standard discrimination between HER2-positive and HER2-low or HER2-negative tumors 2 h after injection (SUVmax 16.9 ± 7.6 vs. 3.6 ± 1.4, p < 0.005). The 99mTc-ZHER2:41071 uptake in HER2-positive lymph node metastases (SUVmax 6.9 ± 2.4, n = 5) was significantly (p < 0.05) higher than that in HER2-low/negative lymph nodes (SUVmax 3.5 ± 1.2, n = 4). 99mTc-ZHER2:41071 visualized hepatic metastases in a patient with liver involvement. Conclusions: Injections of 99mTc-ZHER2:41071 appear safe and exhibit favorable dosimetry. The protein dose of 1000 µg provides the best discrimination between HER2-positive and HER2-low/negative expression of HER2 according to the definition used for current HER2-targeting drugs.

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Dataset Information

Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

Publications

Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

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