Diffuse optical tomography of breast carcinoma: can tumor total hemoglobin concentration be considered as a new promising prognostic parameter of breast carcinoma?

Enhancing Functional Breast Imaging: A sCMOS Camera-Based Lock-in Implementation for Dynamic Tomography

Diffuse optical tomography (DOT) enables the in vivo quantification of tissue chromophores, specifically the discernment of oxy- and deoxy-hemoglobin (HbO and HbR, correspondingly). This specific criterion is useful in detecting and predicting early-stage neoadjuvant breast cancer treatment response. To address the issues of the limited channels in the fiber-dependent breast DOT system and limited signal-to-noise ratio in the camera-dependent systems, we hereby present a camera-based lock-in detection scheme to achieve dynamic DOT with improved SNR, which adopted orthogonal frequency division multiplexing technology. The evaluation of the system performance was conducted on tissue phantoms and neoplastic rats, and the results show that this system boasts the capability of executing parallel measurement utilizing a camera detector, enabling the achievement of highly sensitive, and dynamic tomography for breast screening applications.

The Importance of Hypoxia-Related to Hemoglobin Concentration in Breast Cancer

The importance of hemoglobin (Hgb) as a novel prognostic biomarker in predicting clinical features of cancers has been the subject of intense interest. Anemia is common in various types of cancer including breast cancer (BC) and is considered to be attributed to tumoral hypoxia. Cancer microenvironments are hypoxic compared with normal tissues, and this hypoxia is associated with Hgb concentration. Recent preclinical documents propose a direct or indirect correlation of intratumoral hypoxia, specifically along with acidity, with Hgb concentration and anemia. Analysis of the prognostic value of Hgb in BC patients has demonstrated increased hypoxia in the intratumoral environment. A great number of studies demonstrated that lower concentrations of Hgb before or during common cancer treatments, such as radiation and chemotherapy, is an essential risk factor for poor prognostic and survival, as well as low quality of life in BC patients. This data suggests a potential correlation between anemia and hypoxia in BC. While low Hgb levels are detrimental to BC invasion and survival, identification of a distinct and exact threshold for low Hgb concentration is challenging and inaccurate. The optimal thresholds for Hgb and partial pressure of oxygen (pO2) vary based on different factors including age, gender, therapeutic approaches, and tumor types. While necessitating further investigations, understanding the correlation of Hgb levels with tumoral hypoxia and oxygenation could improve exploring strategies to overcome radio-chemotherapy related anemia in BC patients. This review highlights the collective association of Hgb concentration and hypoxia condition in BC progression.

US-guided Diffuse Optical Tomography: Clinicopathological Features Affect Total Hemoglobin Concentration in Breast Cancer

PURPOSE: To investigate breast cancers total hemoglobin concentration (THC) characteristics and its association with clinical pathologic findings. MATERIALS AND METHODS: The study was approved by the institutional review board and all patients provided written informed consent. 447 breast cancer patients, totally 455 lesions were included in our study. The size and THC of breast lesions were measured by conventional ultrasound (US) and US-guided Diffuse Optical Tomography (DOT) 1–2 days before surgery. Clinical and pathology information of patients was collected. RESULT: The average THC values of ER- or PR- lesions were significantly higher than the positive ones (P = .005 and P = .01,respectively); The average THC values of axillar LN+ or LVI+ were higher than the negative ones (P = .042 and P = .043, respectively). No significant THC difference was found in groups of infiltrating vs. non-infiltrating, HER2+ vs. HER2-, Ki67 high vs. Ki67 low, and different menstrual phases (P = .457, P = .917, P = .417, P = .213, respectively).The incidence ages and the lesion-nipple distances of T3 patients were lower than that of T1 and T2 (P < .001 and P < .001 respectively). The THC values and Ki67 indexes of T2 and T3 lesions were similar, but were higher than that of the T1 group (P < =0.001 and P = .006, respectively). CONCLUSION: Clinicopathological features of breast cancer, such as ER and PR status, axillary lymph node metastasis, lymphovascular invasion, correlate with THC values. Furthermore, the Ki67 indexes can be predicted using tumor size and THC, useful for pre-surgical evaluation of cancer biology and real-time, non-invasive monitoring of NAC efficacy.

Correlations Among Ultrasound-Guided Diffuse Optical Tomography, Microvessel Density, and Breast Cancer Prognosis

OBJECTIVES

To investigate the correlation among ultrasound-guided diffuse optical tomography (DOT), microvessel density, and breast cancer prognosis.

METHODS

Before surgery, the total hemoglobin (Hb) concentrations of 184 female patients with breast cancer with only a single lesion were measured. During follow-up, 23 patients had recurrence or metastatic disease after surgery. Among these patients, 18 with recurrence or metastatic disease within 3 years after surgery were paired with 18 patients without recurrence or metastatic disease. We retrospectively reviewed the pathologic sections of those 36 patients, conducted immunohistochemical staining, and counted the microvessel densities. Then we analyzed the correlation between microvessel density and total Hb, compared total Hb and microvessel density among breast cancers with different prognoses, and tested the value of DOT in predicting the prognosis of breast cancer.

RESULTS

Microvessel density and total Hb were linearly correlated (r = 0.584; P < .001). Total Hb and microvessel density were significantly increased in the metastasis group (P = .001 and .027, respectively). A receiver operating characteristic curve analysis showed that at a total Hb cutoff value of 221.7 μmol/L, the sensitivity, specificity, and area under the curve of DOT for predicting recurrence or metastasis were 0.826, 0.516, and 0.660, respectively.

CONCLUSIONS

The total Hb concentration can reflect a tumor's blood supply. Patients with a high total Hb concentration and microvessel density have a higher risk for a poorer prognosis. Total Hb can be used as an indicator of breast cancer prognosis. Diffuse optical tomography can help physicians identify patients with a high risk of metastasis and make clinical decisions.

Diffuse optical tomography changes correlate with residual cancer burden after neoadjuvant chemotherapy in breast cancer patients

PURPOSE

Breast cancer (BC) patients who achieve a favorable residual cancer burden (RCB) after neoadjuvant chemotherapy (NACT) have an improved recurrence-free survival. Those who have an unfavorable RCB will have gone through months of ineffective chemotherapy. No ideal method exists to predict a favorable RCB early during NACT. Diffuse optical tomography (DOT) is a novel imaging modality that uses near-infrared light to assess hemoglobin concentrations within breast tumors. We hypothesized that the 2-week percent change in DOT-measured hemoglobin concentrations would associate with RCB.

METHODS

We conducted an observational study of 40 women with stage II-IIIC BC who received standard NACT. DOT imaging was performed at baseline and 2 weeks after treatment initiation. We evaluated the associations between the RCB index (continuous measure), class (categorical 0, I, II, III), and response (RCB class 0/I = favorable, RCB class II/III = unfavorable) with changes in DOT-measured hemoglobin concentrations.

RESULTS

The RCB index correlated significantly with the 2-week percent change in oxyhemoglobin [HbO₂] (r = 0.5, p = 0.003), deoxyhemoglobin [Hb] (r = 0.37, p = 0.03), and total hemoglobin concentrations [HbT] (r = 0.5, p = 0.003). The RCB class and response significantly associated with the 2-week percent change in [HbO₂] (p ≤ 0.01) and [HbT] (p ≤ 0.02). [HbT] 2-week percent change had sensitivity, specificity, positive, and negative predictive values for a favorable RCB response of 86.7, 68.4, 68.4, and 86.7%, respectively.

CONCLUSION

The 2-week percent change in DOT-measured hemoglobin concentrations was associated with the RCB index, class, and response. DOT may help guide NACT for women with BC.

US-localized diffuse optical tomography in breast cancer: comparison with pharmacokinetic parameters of DCE-MRI and with pathologic biomarkers

BACKGROUND

To correlate parameters of Ultrasonography-guided Diffuse optical tomography (US-DOT) with pharmacokinetic features of Dynamic contrast-enhanced (DCE)-MRI and pathologic markers of breast cancer.

METHODS

Our institutional review board approved this retrospective study and waived the requirement for informed consent. Thirty seven breast cancer patients received US-DOT and DCE-MRI with less than two weeks in between imaging sessions. The maximal total hemoglobin concentration (THC) measured by US-DOT was correlated with DCE-MRI pharmacokinetic parameters, which included K(trans), k ep and signal enhancement ratio (SER). These imaging parameters were also correlated with the pathologic biomarkers of breast cancer.

RESULTS

The parameters THC and SER showed marginal positive correlation (r = 0.303, p = 0.058). Tumors with high histological grade, negative ER, and higher Ki-67 expression ≥ 20% showed statistically higher THC values compared to their counterparts (p = 0.019, 0.041, and 0.023 respectively). Triple-negative (TN) breast cancers showed statistically higher K(trans) values than non-TN cancers (p = 0.048).

CONCLUSION

THC obtained from US-DOT and K(trans) obtained from DCE-MRI were associated with biomarkers indicative of a higher aggressiveness in breast cancer. Although US-DOT and DCE-MRI both measured the vascular properties of breast cancer, parameters from the two imaging modalities showed a weak association presumably due to their different contrast mechanisms and depth sensitivities.