Tumor Vascularization in Cervical Cancer by 3-Dimensional Power Doppler Angiography

Based on 3D-PDU and clinical characteristics nomogram for prediction of lymph node metastasis and lymph-vascular space invasion of early cervical cancer preoperatively

PURPOSE

To develop and validate a nomogram based on 3D-PDU parameters and clinical characteristics to predict LNM and LVSI in early-stage cervical cancer preoperatively.

MATERIALS AND METHODS

A total of first diagnosis 138 patients with cervical cancer who had undergone 3D-PDU examination before radical hysterectomy plus lymph dissection between 2014 and 2019 were enrolled for this study. Multivariate logistic regression analyses were performed to analyze the 3D-PDU parameters and selected clinicopathologic features and develop a nomogram to predict the probability of LNM and LVSI in the early stage. ROC curve was used to evaluate model differentiation, calibration curve and Hosmer-Lemeshow test were used to evaluate calibration, and DCA was used to evaluate clinical practicability.

RESULTS

Menopause status, FIGO stage and VI were independent predictors of LNM. BMI and maximum tumor diameter were independent predictors of LVSI. The predicted AUC of the LNM and LSVI models were 0.845 (95%CI,0.765-0.926) and 0.714 (95%CI,0.615-0.813). Calibration curve and H-L test (LNM groups P = 0.478; LVSI P = 0.783) all showed that the predicted value of the model had a good fit with the actual observed value, and DCA indicated that the model had a good clinical net benefit.

CONCLUSION

The proposed nomogram based on 3D-PDU parameters and clinical characteristics has been proposed to predict LNM and LVSI with high accuracy, demonstrating for the first time the potential of non-invasive prediction. The probability derived from this nomogram may have the potential to provide valuable guidance for physicians to develop clinical individualized treatment plans of FIGO patients with early cervical cancer.

Quantitative analysis of superb microvascular imaging for monitoring tumor response to chemoradiotherapy in locally advanced cervical cancer

Objectives

As an ultrasound (US) image processing method, superb microvascular imaging (SMI) extracts and visualizes flow signals from vessels through advanced clutter suppression technology. We investigated the feasibility of SMI in monitoring treatment response in patients with locally advanced cervical cancer (LACC) undergoing chemoradiotherapy (CRT).

Methods

Forty-nine patients underwent CRT and received SMI examination at 3 time points: before therapy (baseline), 3 weeks during, and 1 month after CRT. The maximum tumor diameter (Dmax), vascularity index (VI), and their percentage changes (ΔDmax and ΔVI) were calculated. ΔDmax was compared with MRI results as the reference standard.

Results

Based on the MRI findings, 44 were classified as complete response (CR) group and 5 as partial response (PR) group. The Dmax and ΔDmax showed decrease in CR and PR groups at 3 weeks during CRT (P< 0.05), but no significant difference between the two groups (P > 0.05). Compared to the baseline, significant decrease in VI and ΔVI were observed at during and after treatment in the two groups (P< 0.05). Moreover, there were significant differences in VI and ΔVI at 3 weeks during CRT between the CR and PR groups (P< 0.05). ΔVI at 3 weeks during CRT showed a better predictive performance for responder prognosis than VI (AUC = 0.964, AUC = 0.950, respectively, P = 0.001), with a cut-off value of 41.6% yielding 100% sensitivity and 86.4% specificity.

Conclusions

The SMI parameters (VI and ΔVI) have potential for monitoring treatment response in LACC.

Classification of Vascular Hotspots and Micro-Vessel Flow Velocity Waveforms in Low-Grade Squamous Intraepithelial Lesions and HPV Condyloma of the Cervix

To assess hotspot micro-vessel flow velocity waveforms in human papillomavirus (HPV) cervical infections using transvaginal power Doppler ultrasound (TV-PDU) and to explore the associations of these sonographic parameters with HPV condyloma and low-grade squamous intraepithelial lesions (LSIL) of the cervix. A total of 39 patients with cervical HPV infections with abnormal cytology and colposcopy results (26 cases of LSIL; 13 cases of HPV condyloma) were enrolled to assess the vascular classification of the cervix and micro-vessel flow velocity using TV-PDU before treatment; 40 individuals with a pathologically normal cervix were used as the control group; seven parameters were measured, including vascular grading classification (Class I, Class II, and Class III), lowest pulsatility index (PI), resistance index (RI), peak systolic velocity (PS), end-diastolic velocity (ED), time average maximum velocity (TAMV), and the vascular index (VI = PS/ED). According to vascular classification, most LSILs were class I (69.2%, 18/26), followed by class II (26.9%, 7/26) and class III (3.8%, 1/26). Most HPV condylomas were class I (92.3%, 12/13), and one was class II (7.7%, 1/13). PI, RI, VI (p < 0.0001), and the PSs (p < 0.05) were significantly lower in these cases than in the controls. The ED and TAMV were not significantly different between the patients and controls (p = 0.4985 and p = 0.1564). No sonographic parameter was significantly different between LSIL and HPV condyloma. The mean PI, RI, and VI were significantly lower in LSIL than in the controls. For HPV condyloma, a PI of 1.07 had an 84.6% sensitivity, 85.0% specificity, and an AUC of 88.8%; for LSIL, a PI of 1.08 had a 100% sensitivity, 85% specificity, and an AUC of 94.2%; for HPV infection (HPV condyloma + LSIL), a PI of 1.08 had a 94.9% sensitivity, 85% specificity, and an AUC of 92.4%. Hotspot vascular classification and micro-vessel flow velocity waveforms may provide a potential practical method for the auxiliary diagnosis of cervical HPV infection. The PI may represent a valuable index for distinguishing the micro-vessel flow velocity waveforms in LSIL and HPV condyloma. Since the case numbers were limited in the current study, further validation is needed.

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.

3D vocal power Doppler sonography for the estimation of tumor volume and vascularization in stage IB1 cervical cancer

PURPOSE

To evaluate the tumor's volume and intratumoral vascularization with 3D vocal power Doppler ultrasound in patients with stage 1B1 cervical cancer.

METHODS

This was a prospective study on patients with cervical cancer and stage 1B1 disease, which took place between 2012 and 2015. All women had an initial 2D ultrasound examination for the estimation of the tumor volume. Following this, 3D volumes of the cervix were acquired and were further analyzed using the Virtual Organ Computer Aided Analysis (VOCAL) program. In the selected volume, the vascular pattern (linear or complex vascularization) was also examined. The ultrasonographic findings were compared to the histological ones following surgery.

RESULTS

Twenty-seven patients were included. The average cervical tumor volume measured by the 2D ultrasound and 3D VOCAL-PD were 3.14 and 3.08 cm³, respectively. Both 2D and 3D VOCAL-PD overestimated the tumor staging. Further analysis showed a statistically significant superiority of 2D ultrasound over 3D VOCAL-PD for tumors equal or smaller than 2.5 cm³ with linear vascularity (p < 0.001), while for tumors of larger volume with complex vascularization, a statistically significant superiority of 3D VOCAL-PD was confirmed (p < 0.001).

CONCLUSIONS

3-D VOCAL-PD is extremely accurate and superior to 2D ultrasound for the estimation of tumor volume and vascularization when it is more than 2.5 cm³ and has a complex vascularization in patients with stage 1B1 cervical cancer.

Expression of Angiopoietin and VEGF in Cervical Cancer and its Clinical Significance

OBJECTIVE

The aim of this study was to evaluate the expression of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF) in cervical cancer and its clinical significance.

METHODS

Immunohistochemical assay was used to examine the expression of Ang-1/2 and VEGF in tumor tissue from 56 cervical squamous cell carcinoma patients treated with operation only (SCC-O group), as well as 51 subjects with cervical squamous cell carcinoma treated with neoadjuvant radiotherapy (SCC-RCO group, n=28) or neoadjuvant chemotherapy (SCC-CO group, n=23). Both microvessel density (MVD) and lymphatic vessel density (LVD) were examined in the three groups through detection of CD34 and D2-40 expression in respective tissue samples.

RESULTS

With the progression of cervical cancer, the positive expression scores of Ang-2 and VEGF were significantly increased (p<0.05). Compared with surgical intervention, neoadjuvant chemoradiotherapy significantly reduced the positive expression scores of Ang-1, Ang-2, and VEGF in cervical cancer tissues (p<0.05). The MVD values of the SCC-CO and SCC-RO groups were significantly reduced as compared to the SCC-O group (p<0.05). Similarly, the LVD values of the SCC-CO and SCC-RO groups were also significantly reduced when compared to those of the SCC-O group (p<0.05). However, LVD values of the SCC-CO and SCC-RO groups were not statistical different (p>0.05).

CONCLUSION

Ang-1, Ang-2 and VEGF may play an important role in the development of cervical cancer. Mutual synergism of Ang-2 and VEGF demonstrated a close relationship with the generation of cervical blood and lymphatic vessels. Cervical cancer radiotherapy and chemotherapy could significantly inhibit the formation of blood vessels and lymphatic vessels in tumor tissue.

Comparison between model-predicted tumor oxygenation dynamics and vascular-/flow-related Doppler indices

PURPOSE

Mathematical modeling is a powerful and flexible method to investigate complex phenomena. It discloses the possibility of reproducing expensive as well as invasive experiments in a safe environment with limited costs. This makes it suitable to mimic tumor evolution and response to radiotherapy although the reliability of the results remains an issue. Complexity reduction is therefore a critical aspect in order to be able to compare model outcomes to clinical data. Among the factors affecting treatment efficacy, tumor oxygenation is known to play a key role in radiotherapy response. In this work, we aim at relating the oxygenation dynamics, predicted by a macroscale model trained on tumor volumetric data of uterine cervical cancer patients, to vascularization and blood flux indices assessed on Ultrasound Doppler images.

METHODS

We propose a macroscale model of tumor evolution based on three dynamics, namely active portion, necrotic portion, and oxygenation. The model parameters were assessed on the volume size of seven cervical cancer patients administered with 28 fractions of intensity modulated radiation therapy (IMRT) (1.8 Gy/fraction). For each patient, five Doppler ultrasound tests were acquired before, during, and after the treatment. The lesion was manually contoured by an expert physician using 4D View^® (General Electric Company - Fairfield, Connecticut, United States), which automatically provided the overall tumor volume size along with three vascularization and/or blood flow indices. Volume data only were fed to the model for training purpose, while the predicted oxygenation was compared a posteriori to the measured Doppler indices.

RESULTS

The model was able to fit the tumor volume evolution within 8% error (range: 3-8%). A strong correlation between the intrapatient longitudinal indices from Doppler measurements and oxygen predicted by the model (about 90% or above) was found in three cases. Two patients showed an average correlation value (50-70%) and the remaining two presented poor correlations. The latter patients were the ones featuring the smallest tumor reduction throughout the treatment, typical of hypoxic conditions. Moreover, the average oxygenation value predicted by the model was close to the average vascularization-flow index (average difference: 7%).

CONCLUSIONS

The results suggest that the modeled relation between tumor evolution and oxygen dynamics was reasonable enough to provide realistic oxygenation curves in five cases (correlation greater than 50%) out of seven. In case of nonresponsive tumors, the model failed in predicting the oxygenation trend while succeeded in reproducing the average oxygenation value according to the mean vascularization-flow index. Despite the need for deeper investigations, the outcomes of the present work support the hypothesis that a simple macroscale model of tumor response to radiotherapy is able to predict the tumor oxygenation. The possibility of an objective and quantitative validation on imaging data discloses the possibility to translate them as decision support tools in clinical practice and to move a step forward in the treatment personalization.

Contrast-enhanced ultrasonography of cervical carcinoma: perfusion pattern and relationship with tumour angiogenesis

OBJECTIVE

This study aimed to investigate the use of contrast-enhanced ultrasonography (CEUS) and time-intensity curves to assess angiogenesis in cervical cancer.

METHODS

60 patients who were scheduled to undergo radical surgery for biopsy-proven cervical cancers underwent CEUS. Surgical tissue sections from 32 patients who did not receive neoadjuvant chemotherapy were analyzed with CD34 staining to estimate intratumoral microvessel density (MVD). CEUS images were analyzed for maximum intensity (IMAX), rise time (RT), time to peak (TTP) and mean transit time.

RESULTS

Cervical lesions had a higher IMAX and shorter RT and TTP (p < 0.001) than reference regions. There was a linear association between the IMAX of the cervical lesion and the mean intratumoral MVD (r = 0.624, p < 0.001). There were no significant differences in CEUS variables according to histological type, grade and stage.

CONCLUSION

Quantitative CEUS variables have potential use for monitoring perfusion changes in tumours after non-surgical therapy for advanced cervical cancer.

ADVANCES IN KNOWLEDGE

The article demonstrates the capability and value of quantitative CEUS as a non-invasive strategy for detecting the perfusion and angiogenic status of cervical cancer. Quantitative CEUS variables have potential use for monitoring tumour response to non-surgical therapy.

Three-Dimensional Power Doppler Ultrasound for Predicting Response and Local Recurrence After Concomitant Chemoradiation Therapy for Locally Advanced Carcinoma of the Cervix

OBJECTIVE

The aim of this study was to assess the potential role of 3-dimensional power Doppler ultrasound (3D-PDUS) for predicting clinical response and recurrence after chemoradiotherapy in advanced-stage cervical cancer.

METHODS

This is a prospective study comprising a series of women with histological proven diagnosis of locally advanced stage (stage IB2-IVA) carcinoma of the cervix and submitted to chemoradiaton therapy. Before the start of chemoradiation therapy, all women were submitted to undergo transvaginal 3D-PDUS for assessing tumor volume and tumor vascularization. After finishing chemoradiation, all women were evaluated to assess clinical response. Complete clinical response was determined when no residual tumor was apparent. Partial clinical response (PCR) was determined when persistent residual tumor was observed and confirmed by histological analysis. Patients with PCR underwent salvage surgery. Local recurrence was defined as reappearance of the tumor within the pelvis at any time during follow-up.

RESULTS

Thirty-nine women (mean age, 50.3 years; ranging from 30 to 81 years) were included in the study. Complete clinical response was achieved in 29 women (70.7%), whereas 10 women (24.4%) had PCR. Eight women (20.5%) had local recurrence during follow-up. We did not find statistical significant differences in tumor size, volume, and vascularization between those women who had complete clinical response and those who had PCR and between those who had local recurrence and those who had not.

CONCLUSIONS

A single 3D-PDUS assessment of tumor size and vascularization before treatment seems to be of limited value for predicting tumor response to chemoradiation therapy and for predicting tumor recurrence in women with locally advanced carcinoma of the cervix.

Application of Volumetric Modulated Arc Therapy and Simultaneous Integrated Boost Techniques to Prepare "Safe Margin" in the Rabbit VX2 Limb Tumor Model

Background

In this study, we aimed to establish the rabbit VX2 limb tumor model, and then prepare a “necrotic zone” as a safe margin by volumetric modulated arc therapy and simultaneous integrated boost (VMAT-SIB) technique applied in the areas where the tumor is located adjacent to the bone (GTV_boost area).

Material/Methods

Rabbits in the control group (n=10) were not treated, while those in the test group (n=10) were treated with the SIB schedule delivering a dose of 40Gy, 35Gy, 30Gy, and 25Gy to the GTV_boost, GTV (gross tumor volume), CTV (clinical target volume), and PTV (planning target volume) in 10 fractions. Magnetic resonance diffusion-weighted imaging (MRDWI), 3-dimensional power Doppler angiography (3D-PDA), and histological changes were observed after radiotherapy.

Results

After radiotherapy, the two groups showed a significant difference in the GTV_boost area. In the test group, the tumor necrosis showed a significantly low signal in DWI and high signal in apparent diffusion coefficient (ADC) maps. The 3D-PDA observation showed that tumor vascular structures decreased significantly. Histological analysis demonstrated that a necrotic zone could be generated in the GTV_boost area, and microscopic examination observed cell necrosis and fibroplasia.

Conclusions

This studies demonstrated the feasibility of using VMAT-SIB technique in the rabbit VX2 limb tumor model. The formation of a necrotic zone can be effectively defined as safe margin in the GTV_boost area. showing potential clinical applicability.

Doppler Ultrasound Flow Evaluation of the Uterine Arteries Significantly Correlates with Tumor Size in Cervical Cancer Patients

PURPOSE

The aim of this present study was to evaluate the sonographic correlation between Doppler flow characteristics of the uterine arteries and tumor size in patients with cervical cancer, in order to establish a new potential marker to monitor treatment response.

METHODS

This was a retrospective cohort study of 25 patients who underwent a sonographic evaluation of Doppler flow characteristics of the uterine arteries before surgery or radiochemotherapy for early and locally advanced/advanced cervical cancer, respectively, was analyzed. The primary outcome was the correlation between Doppler flow characteristics of the uterine arteries and tumor size in patients with cervical cancer.

RESULTS

Median age was 49 (range 26-85) years, and mean tumor size was 40.8 ± 17 mm. A significant positive correlation was found between tumor diameter and the uterine artery end-diastolic velocity (r = 0.47, p < 0.05) as well as the peak systolic velocity (r = 0.41, p < 0.05). No correlation was found between tumor size and the pulsatility index or resistance index.

CONCLUSIONS

In cervical cancer, uterine artery velocity parameters are associated with tumor size. This finding could become particularly useful in the follow-up of locally advanced cervical cancer patients undergoing radiochemotherapy or in corroborating the selection of women with more possibility of a high response rate during neoadjuvant chemotherapy before surgery.

Preoperative prediction of lymph node metastasis and deep stromal invasion in women with invasive cervical cancer: prospective multicenter study using 2D and 3D ultrasound

OBJECTIVES

To determine how various objective two-dimensional (2D) and three-dimensional (3D) ultrasound parameters allow prediction of deep stromal tumor invasion and lymph node involvement, in comparison to subjective ultrasound assessment, in women scheduled for surgery for cervical cancer.

METHODS

This was a prospective multicenter trial including 104 women with cervical cancer at FIGO Stages IA2-IIB, verified histologically. Patients scheduled for surgery underwent a preoperative ultrasound examination. The value of various 2D (size, color score) and 3D (volume, vascular indices) ultrasound parameters was compared to that of subjective assessment in the prediction of deep stromal tumor invasion and lymph node involvement. Histology obtained from radical hysterectomy or trachelectomy and pelvic lymphadenectomy was considered as the gold standard for assessment.

RESULTS

All women underwent pelvic lymphadenectomy, with 99 (95%) undergoing subsequent radical surgery; five underwent only pelvic lymphadenectomy because of the presence of a positive sentinel lymph node. Women with deep stromal invasion or lymph node involvement had significantly larger tumors (diameter and volume) but there was no correlation with vascular indices measured on 3D ultrasound. Subjective evaluation was superior (AUC, 0.93; sensitivity, 90.5%; specificity, 97.2%) in the prediction of deep stromal invasion when compared to any objective measurement technique, with maximal tumor diameter at 20.5-mm cut-off (AUC, 0.83; sensitivity, 90.5%; specificity, 61.1%) and 3D tumor volume at 9.1-mm(3) cut-off (AUC, 0.85; sensitivity, 79.4%; specificity, 83.3%) providing the best performance among the objective parameters. Both subjective assessment and objective measurements were poorly predictive of lymph node involvement.

CONCLUSIONS

In women with cervical cancer, subjective ultrasound evaluation allowed better prediction of deep stromal invasion than did objective measurements; however, neither subjective evaluation nor objective parameters were adequate to predict lymph node involvement. 3D vascular indices were ineffective in the prediction of advanced stages of the disease.

The role of ultrasound in the assessment of uterine cervical cancer

Uterine cervical cancer is the second most frequent gynecological malignancy worldwide. The assessment of the extent of disease is essential for planning optimal treatment. Imaging techniques are increasingly used in the pre-treatment work-up of cervical cancer. Currently, MRI for local extent of disease evaluation and PET-scan for distant disease assessment are considered as first-line techniques. Notwithstanding, in the last few years, ultrasound has gained attention as an imaging technique for evaluating women with cervical cancer. In this paper, current knowledge about the use of ultrasound for assessing uterine cervical cancer will be reviewed and discussed.

Three-dimensional power Doppler ultrasound in cervical carcinoma: monitoring treatment response to radiotherapy

OBJECTIVES

To investigate, using three-dimensional power Doppler ultrasound (3D-PDU), alterations in cervical intratumoral vascularization during and after radiotherapy.

METHODS

Between 2004 and 2009 we enrolled into the study 37 patients with FIGO Stages IB1-IIB cervical carcinoma who were undergoing radiotherapy. Serial 3D-PDU scans were performed during treatment, providing ultrasonographic measurement of tumor size, vascularization index, flow index and vascularization flow index, as well as monthly for 3 months post-treatment and tri-monthly thereafter, until vascularity was undetectable on two consecutive occasions. Physical examination, cervical cytology and serum marker evaluation were performed every 3-6 months for the first 5 years following treatment. Patients evaluated after a 2-year tumor-free interval and those with clinically assessed positive findings at follow-up underwent 3D-PDU to detect possible local disease.

RESULTS

A total of 329 3D-PDU scans were performed in the 37 women. Cervical tumors and intratumoral vascularization disappeared within 3 months following radiotherapy, except in one patient with persistent disease. Nine patients had disease relapse, in four of whom the recurrence was local. In three of these four, there was recurrence of tumor and vascularization after a complete response. At follow-up, 3D-PDU detected local disease with 75.0% sensitivity and 98.5% specificity, while serum markers detected local disease among 34 patients with squamous cell carcinoma with 20.0% sensitivity and 77.3% specificity.

CONCLUSIONS

Compared with serum markers in cervical squamous cell carcinoma, 3D-PDU has higher sensitivity and specificity for detecting local recurrence or persistence in cervical carcinoma. Thus, 3D-PDU combined with clinical assessment may be a new and safe method for monitoring radiotherapy treatment response and detecting local recurrence.

Three-dimensional power Doppler ultrasound for the study of cervical cancer and precancerous lesions

OBJECTIVE

To evaluate the blood flow characteristics of the cervix in normal women and in women with cervical precancerous lesions or cervical cancer.

METHODS

We studied 165 women with three-dimensional power Doppler ultrasound (3D-PDU), of whom 71 had cervical cancer, 61 had precancerous lesions and 33 were healthy controls. The cervix was manually traced in the stored volumes using 15° rotation steps and the following 3D-PDU indices were calculated: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). These indices were compared among the study groups and were also correlated with features of the precancerous lesions group and cancer group.

RESULTS

The three indices were all statistically significantly higher in the cervical cancer group and precancerous lesions group than in controls (P < 0.001). In addition, significantly higher values of all indices were found in the cervical cancer group than in the precancerous lesions group (P < 0.001). Further analysis according to patient characteristics in the cancer group showed that VI, FI and VFI were not significantly different in relation to grade, histology, presence of positive lymph nodes or lymphovascular space involvement (P > 0.05). However, VI was significantly higher in patients with Stages IIIB-IV cancer than in patients with less advanced disease (P = 0.045). In the cervical cancer group there was a significant positive correlation between 3D-PDU indices and cervical volume.

CONCLUSION

3D-PDU assessment of the cervix reveals significant differences in all indices studied between women with cervical precancerous lesions or cancer and healthy women. In women with cervical cancer, an advanced stage is associated with higher VI, but 3D-PDU indices are not related to other pathological characteristics.

3-D microvessel-mimicking ultrasound phantoms produced with a scanning motion system

Ultrasound techniques are currently being developed that can assess the vascularization of tissue as a marker for therapeutic response. Some of these ultrasound imaging techniques seek to extract quantitative features about vessel networks, whereas high-frequency imaging also allows individual vessels to be resolved. The development of these new techniques, and subsequent imaging analysis strategies, necessitates an understanding of their sensitivities to vessel and vessel network structural abnormalities. Constructing in-vitro flow phantoms for this purpose can be prohibitively challenging, because simulating precise flow environments with nontrivial structures is often impossible using conventional methods of construction for flow phantoms. Presented in this manuscript is a method to create predefined structures with <10 μm precision using a three-axis motion system. The application of this technique is demonstrated for the creation of individual vessel and vessel networks, which can easily be made to simulate the development of structural abnormalities typical of diseased vasculature in vivo. In addition, beyond facilitating the creation of phantoms that would otherwise be very challenging to construct, the method presented herein enables one to precisely simulate very slow blood flow and respiration artifacts, and to measure imaging resolution.

A perspective on vascular disrupting agents that interact with tubulin: preclinical tumor imaging and biological assessment

The tumor microenvironment provides a rich source of potential targets for selective therapeutic intervention with properly designed anticancer agents. Significant physiological differences exist between the microvessels that nourish tumors and those that supply healthy tissue. Selective drug-mediated damage of these tortuous and chaotic microvessels starves a tumor of necessary nutrients and oxygen and eventually leads to massive tumor necrosis. Vascular targeting strategies in oncology are divided into two separate groups: angiogenesis inhibiting agents (AIAs) and vascular disrupting agents (VDAs). The mechanisms of action between these two classes of compounds are profoundly distinct. The AIAs inhibit the actual formation of new vessels, while the VDAs damage and/or destroy existing tumor vasculature. One subset of small-molecule VDAs functions by inhibiting the assembly of tubulin into microtubules, thus causing morphology changes to the endothelial cells lining the tumor vasculature, triggered by a cascade of cell signaling events. Ultimately this results in catastrophic damage to the vessels feeding the tumor. The rapid emergence and subsequent development of the VDA field over the past decade has led to the establishment of a synergistic combination of preclinical state-of-the-art tumor imaging and biological evaluation strategies that are often indicative of future clinical efficacy for a given VDA. This review focuses on an integration of the appropriate biochemical and biological tools necessary to assess (preclinically) new small-molecule, tubulin active VDAs for their potential to be clinically effective anticancer agents.