Three-dimensional power Doppler ultrasound in the early assessment of response to concurrent chemo-radiotherapy for advanced cervical cancer

Assessment of cervical vascularization density in patients with locally advanced squamous cell cervical carcinoma evaluated in colour Doppler and power Doppler functions

Purpose

The aim of the prospective study was to assess changes during treatment and prognostic significance of cervical vascularization density in patients with cervical squamous cell carcinoma (SCC) staged II B and III B and to find relationship of cervical vascularization density with tumour diameter, grading, staging and age of patients.

Methods

The study group included 50 patients who underwent transvaginal Doppler ultrasonography prior to chemoradiotherapy, after external beam radiation therapy (EBRT) and 6 weeks after HDR brachytherapy. The colour Doppler (CD) vascularity index (CDVI) and the power Doppler (PD) vascularity index (PDVI) in cervical tumour were examined.

Results

CDVI and PDVI values decreased significantly during radiotherapy (0.13 (95% CI 0.09–0.16); 0.09 (95% CI 0.07–0.11) and 0.05 (95% CI 0.03–0.06) for CDVI (p < 0.001) and 0.26 (95% CI 0.22–0.31); 0.18 (95% CI 0.14–0.22) and 0.08 (95% CI 0.06–0.11) for PDVI (p < 0.001)). No statistically significant associations of CDVI and PDVI with tumour diameter, grading, staging and age of patients were found. The higher (above median) CDVI values before EBRT were associated with better OS (p = 0.041). The higher (above median) PDVI values before EBRT were associated with superior DFS (p = 0.011) and OS (p < 0.001). DFS and OS did not differ significantly regarding CDVI and PDVI values after EBRT and after the treatment.

Conclusions

In the study group, cervical vascularization density evaluated in CD and PD functions did not depend on tumour diameter, grading, staging and age of patients and decreased during radiotherapy. The prognosis for our patients with CDVI and PDVI before the treatment above the median value was better than compared to patients with these parameters below the median value.

Photoacoustic imaging as a tool to probe the tumour microenvironment

The tumour microenvironment (TME) is a complex cellular ecosystem subjected to chemical and physical signals that play a role in shaping tumour heterogeneity, invasion and metastasis. Studying the roles of the TME in cancer progression would strongly benefit from non-invasive visualisation of the tumour as a whole organ in vivo, both preclinically in mouse models of the disease, as well as in patient tumours. Although imaging techniques exist that can probe different facets of the TME, they face several limitations, including limited spatial resolution, extended scan times and poor specificity from confounding signals. Photoacoustic imaging (PAI) is an emerging modality, currently in clinical trials, that has the potential to overcome these limitations. Here, we review the biological properties of the TME and potential of existing imaging methods that have been developed to analyse these properties non-invasively. We then introduce PAI and explore the preclinical and clinical evidence that support its use in probing multiple features of the TME simultaneously, including blood vessel architecture, blood oxygenation, acidity, extracellular matrix deposition, lipid concentration and immune cell infiltration. Finally, we highlight the future prospects and outstanding challenges in the application of PAI as a tool in cancer research and as part of a clinical oncologist's arsenal.

Summary: This Review details the potential of photoacoustic imaging to visualise features of the tumour microenvironment such as blood vessels, hypoxia, fibrosis and immune infiltrate to provide unprecedented insight into tumour biology.

PRospective Imaging of CErvical cancer and neoadjuvant treatment (PRICE) study: role of ultrasound to assess residual tumor in locally advanced cervical cancer patients undergoing chemoradiation and radical surgery

OBJECTIVE

To determine the diagnostic performance of two-dimensional (2D) ultrasound parameters, three-dimensional (3D) power Doppler and contrast-enhanced indices in detecting residual disease in locally advanced cervical cancer patients triaged to neoadjuvant treatment followed by radical surgery.

METHODS

Between October 2010 and June 2014, we screened 108 women with histologically documented locally advanced cervical cancer Stage IB2-IVA, of whom 88 were included in the final analysis. 2D ultrasound parameters, 3D power Doppler and contrast-ultrasound parameters were assessed 5 weeks after the end of neoadjuvant chemoradiation therapy. The pathological response was defined as complete (absence of any residual tumor after treatment) or partial (including microscopic and/or macroscopic residual tumor at pathology examination). The two response groups were compared and receiver-operating characteristics (ROC) curves generated to determine the best cut-off value of sonographic tumor diameter to predict residual disease. Histology was considered as reference.

RESULTS

Complete pathological response to chemoradiation was observed in 40 (45.5%) patients and partial response in 48 (54.5%). The presence of residual disease, as confirmed at pathology examination, was detected by 2D grayscale ultrasound with a sensitivity of 64.6% and specificity of 65%. Color Doppler examination in the cases with lesions visualized on grayscale imaging detected the presence of residual disease, confirmed at pathology, with a sensitivity of 87.1% and specificity of 21.4%. The best area under the ROC curve (0.817) was for the detection of pathological residual disease of at least 6 mm in diameter, using a cut-off value of 12 mm for the largest tumor diameter assessed using 2D grayscale ultrasound (sensitivity, 95%; specificity, 70.6%). Neither 3D vascular indices nor contrast-ultrasound parameters obtained for lesions suspected at ultrasound following chemoradiation differed significantly between patients with histological complete and those with partial response.

CONCLUSIONS

Our results show that grayscale and color Doppler ultrasound have a low level of diagnostic performance in detecting residual disease after neoadjuvant chemoradiation in patients with locally advanced cervical cancer. The best performance was achieved in detection of macroscopic (≥ 6 mm) residual disease. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.