Quantitative measurements of perfusion and permeability of oropharyngeal and oral cavity cancer, recurrent disease, and associated lymph nodes using first-pass contrast-enhanced computed tomography studies

Assessment of Computed Tomography Perfusion Research Landscape: A Topic Modeling Study

The number of scholarly articles continues to rise. The continuous increase in scientific output poses a challenge for researchers, who must devote considerable time to collecting and analyzing these results. The topic modeling approach emerges as a novel response to this need. Considering the swift advancements in computed tomography perfusion (CTP), we deem it essential to launch an initiative focused on topic modeling. We conducted a comprehensive search of the Scopus database from 1 January 2000 to 16 August 2023, to identify relevant articles about CTP. Using the BERTopic model, we derived a group of topics along with their respective representative articles. For the 2020s, linear regression models were used to identify and interpret trending topics. From the most to the least prevalent, the topics that were identified include "Tumor Vascularity", "Stroke Assessment", "Myocardial Perfusion", "Intracerebral Hemorrhage", "Imaging Optimization", "Reperfusion Therapy", "Postprocessing", "Carotid Artery Disease", "Seizures", "Hemorrhagic Transformation", "Artificial Intelligence", and "Moyamoya Disease". The model provided insights into the trends of the current decade, highlighting "Postprocessing" and "Artificial Intelligence" as the most trending topics.

Advanced Techniques in Head and Neck Cancer Imaging: Guide to Precision Cancer Management

Precision treatment requires precision imaging. With the advent of various advanced techniques in head and neck cancer treatment, imaging has become an integral part of the multidisciplinary approach to head and neck cancer care from diagnosis to staging and also plays a vital role in response evaluation in various tumors. Conventional anatomic imaging (CT scan, MRI, ultrasound) remains basic and focuses on defining the anatomical extent of the disease and its spread. Accurate assessment of the biological behavior of tumors, including tumor cellularity, growth, and response evaluation, is evolving with recent advances in molecular, functional, and hybrid/multiplex imaging. Integration of these various advanced diagnostic imaging and nonimaging methods aids understanding of cancer pathophysiology and provides a more comprehensive evaluation in this era of precision treatment. Here we discuss the current status of various advanced imaging techniques and their applications in head and neck cancer imaging.

Comparison of CECT and CT perfusion in differentiating benign from malignant neck nodes in oral cavity cancers

Aim

The objective of the study was to assess the performance of CT Perfusion in comparison to CECT for preoperative detection of metastases to lymph nodes in squamous cell cancers of oral cavity.

Methods

Twenty-five patients with squamous cell cancers of oral cavity underwent CECT and CTP. Two radiologists evaluated CECT and CTP parameters independently. Surgery and post-operative histopathology was performed in all patients.

Results

Level wise analysis of the largest node was done. 102 lymph nodes on CECT and 82 lymph nodes on CTP were correlated with post-operative histopathological findings. CECT had a sensitivity, specificity and accuracy of 75 %, 98.6 % and 91.2 %(p-value <0.001) respectively in differentiating benign from metastatic nodes. Mean transit time[MTT] was significantly the most accurate CTP parameter and carried a sensitivity, specificity, accuracy and AUC of 90.5 %, 93.4 %, 92.7 % and 0.96 (p < 0.001). The sensitivity of MTT was higher than the sensitivity of overall CECT.

Conclusions

CTP is a promising tool for detection of metastatic cervical nodes in squamous cell cancers of the oral cavity.

The diagnostic performance of perfusion CT in the detection of local tumor recurrence in head and neck cancer

BACKGROUND

Detecting local tumor recurrence from post-treatment changes in head and neck cancer (HNC) remains a challenge. Based on the hypothesis that post-therapeutically altered tissue is bradytroph, lower perfusion values are expected in perfusion CT (PCT) while higher perfusion values are expected in recurrent malignant tissue.

OBJECTIVES

This prospective study investigates PCT for post-treatment recurrent HNC detection with a maximum slope algorithm.

METHODS

A total of 80 patients who received PCT of the head and neck for post-therapy follow-up, of which 63 had no tumor recurrence and 17 presented a histopathologically confirmed recurrence were examined. Regions of interest were placed in the location of the initial tumor, in reference ipsilateral nuchal muscle tissue and the corresponding internal carotid artery. Perfusion was calculated using a single-input maximum slope algorithm.

RESULTS

With PCT, recurrent HNC can be differentiated from post-treatment tissue (p < 0.05). It further allows delineating recurrent tumor tissue from benign nuchal tissue of reference (p < 0.05). PCT data of patients with and without recurrent HNC are comparable as perfusion values of reference tissues in patients with and without HNC do not differ (p > 0.05).

CONCLUSIONS

PCT in combination with a commercially available maximum slope algorithm offers radiologists a reliable imaging tool to detect recurrent head and neck cancer within post-therapeutically altered tissue.

An application study of CT perfusion imaging in assessing metastatic involvement of perigastric lymph nodes in patients with T1 gastric cancer

OBJECTIVE

To assess metastatic involvement of perigastric lymph nodes (PLNs) in patients with T1 gastric cancer by using CT perfusion imaging (CTPI).

METHODS

A total of 82 annotated PLNs of 33 patients with T1 gastric cancer confirmed by endoscopic ultrasonography underwent CTPI and portal phase CT scan before operation. The scan data were post-processed to acquire perfusion maps and calculate perfusion parameters including blood flow (BF) and permeability surface (PS). A radiologist measured the short axis diameters and perfusion parameters of PLNs. According to the post-operative pathology result, PLNs were divided into two groups: metastatic and inflammatory LNs. Perfusion parameters values and the size of PLNs between two groups were respectively compared statistically by t-test, and a receiver operating characteristic curve analysis was used to determine the optimal diagnostic cut-off value with sensitivity, specificity and area under the curve.

RESULTS

Examined 82 PLNs were metastatic in 45 (54.9%) and inflammatory in 37 (45.1%). The mean values of perfusion parameters and the short axis diameters in metastatic and inflammatory PLNs, respectively, were BF of 97.48 vs 81.21 ml/100 mg /min (p < 0.001), PS of 45.11 vs 36.80 ml/100 mg /min (p < 0.001), and the size of 1.51 cm vs 1.29 cm (p = 0.059). The sensitivity of 84.4%, specificity of 67.6% and area under the curve of 0.826 for BF with cut-off value of 88.89 ml/100 mg /min for differentiating metastatic from inflammatory nodes were higher than those of PS or the size of PLNs (p < 0.001).

CONCLUSION

CT perfusion parameters values were different between metastatic and inflammatory PLNs in T1 gastric cancer. BF value may be the most reliable diagnostic marker of metastatic PLNs, and it is helpful for clinicians to choose treatment modality or management plan in T1 gastric cancer patients.

ADVANCES IN KNOWLEDGE

CTPI gives information on vascularization of LNs.BF value might be a more effective marker than PS or the size of LNs for differentiating metastatic from inflammatory LNs in patients with T1 gastric cancer.

Spectral CT and its specific values in the staging of patients with non-small cell lung cancer: technical possibilities and clinical impact

AIM

To investigate how spectral computed tomography (SCT) values impact the staging of non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

One hundred and thirteen patients with confirmed NSCLC were included in a prospective cohort study. All patients underwent single-phase contrast-enhanced SCT (using the fast tube voltage switching technique, 80-140 kV). SCT values (iodine content [IC], spectral slope pitch, and radiodensity increase) of malignant tissue (primary and metastases) and lymph nodes (LNs) were measured. Adrenal masses were evaluated in a virtual non-contrast series (VNS). If pulmonary embolism was present, pulmonary perfusion was analysed as an additional finding.

RESULTS

Fifty-two untreated primary NSCLC lesions were evaluable. Lung adenocarcinoma had significantly higher normalised IC (NIC: 19.37) than squamous cell carcinoma (NIC: 12.03; p=0.035). Pulmonary metastases were not significantly different from benign lung nodules. A total of 126 LNs were analysed and histologically proven metastatic LNs (2.08 mg/ml) had significantly lower IC than benign LNs (2.58 mg/ml; p=0.023). Among 34 adrenal masses, VNS identified adenomas with high sensitivity (91%) and specificity (100%). In two patients, a perfusion defect due to pulmonary embolism was detected in the iodine images.

CONCLUSION

SCT may contribute to the differentiation of histological NSCLC subtypes and improve the identification of LN metastases. VNS differentiates adrenal adenoma from metastasis. In case of pulmonary embolism, iodine imaging can visualise associated pulmonary perfusion defects.

Multidetector Row Computed Tomography in Maxillofacial Imaging

Multidetector row CT (MDCT) offers superior soft tissue characterization and is useful for diagnosis of odontogenic and nonodontogenic cysts and tumors, fibro-osseous lesions, inflammatory, malignancy, metastatic lesions, developmental abnormalities, and maxillofacial trauma. The rapid advances in MDCT technology, including perfusion CT, dual-energy CT, and texture analysis, will be an integrated anatomic and functional high-resolution scan, which will help in diagnosis of maxillofacial lesions and overall patient care.

Functional magnetic resonance imaging of head and neck cancer: Performance and potential

Functional magnetic resonance imaging (MRI) of tumors of the head and neck usually encompasses diffusion-weighted imaging (DWI) and intravenous (IV) contrast T1 dynamic perfusion imaging (DCE-MRI or PWI). Both techniques can characterize different tissues by probing into their microstructure, providing a novel approach in oncological imaging. In this pictorial review, we will cover the important technical aspects of DWI and PWI, the pathophysiological background and the current applications and potential of these functional MRI techniques in the imaging of head and neck cancer.

Diagnostic Performance of Adaptive 4D Volume Perfusion CT for Detecting Metastatic Cervical Lymph Nodes in Head and Neck Squamous Cell Carcinoma

OBJECTIVE

The purpose of this study was to investigate the diagnostic performance of adaptive 4D volume perfusion CT covering the entire neck for detecting metastatic nodes in patients with head and neck squamous cell carcinoma.

SUBJECTS AND METHODS

Thirty patients with histologically confirmed disease were enrolled. The relation between perfusion parameters and nodal size was analyzed, and perfusion parameters were compared between metastatic and benign nodes. The diagnostic capability for detecting metastatic nodes was evaluated.

RESULTS

Significant inverse correlations with nodal size were found for blood flow (r = -0.40, p = 0.002), blood volume (r = -0.32, p = 0.02), and permeability surface product (r = -0.27, p = 0.04) of the metastatic nodes. All three parameters had significantly higher values in association with nodal maximum diameter < 10 mm compared with diameter ≥ 10 mm (blood flow, p = 0.004; blood volume, p = 0.01; permeability surface product, p = 0.02). Among the nodes with maximum diameter < 10 mm, blood flow of the metastatic nodes was significantly higher than that of the benign nodes (p = 0.02), whereas among the nodes ≥ 10 mm in diameter, the mean transit time of the metastatic nodes was significantly lower than that of the benign nodes (p = 0.04). In multivariate analysis, blood flow in nodes with maximum diameter < 10 mm had a significant association with the detection of metastatic nodes. The sensitivity and specificity of blood flow for differentiating metastatic from benign nodes were 73.3% and 70.8%.

CONCLUSION

Findings from 4D volume perfusion CT covering the entire neck may be informative for characterization of cervical nodes. It is worthwhile to include the examination in nodal staging of head and neck squamous cell carcinoma.

Is computed tomography perfusion a useful method for distinguishing between benign and malignant neck masses?

Evaluation of neck masses is frequent in ear, nose, and throat clinics. Successful outcomes associated with neck mass are directly related to rapid diagnosis and accurate treatment for each patient. Late diagnosis of a malignant mass increases the magnitude of morbidity and the rate of mortality of the disease. Although magnetic resonance imaging and computed tomography (CT) examinations are important tools for evaluating head and neck pathologies, they do not allow functional evaluation. For this reason, CT perfusion (CTP) as a method of functional evaluation for distinguishing benign from malignant masses is gaining attention. The utility of CTP for distinguishing between benign and malignant mass lesions was investigated in 35 patients with masses in the neck (11 benign, 24 malignant). CTP was shown to be a useful method for identifying head and neck tumors and blood volume values to enable the differential diagnosis of benign and malignant head and neck tumors.

Computed Tomography Perfusion Imaging for the Diagnosis of Hepatic Alveolar Echinococcosis

Objective

Alveolar echinococcosis (AE) is a rare life-threatening parasitic infection. Computed tomography perfusion (CTP) imaging has the potential to provide both quantitative and qualitative information about the tissue perfusion characteristics. The purpose of this study was the examination of the characteristic features and feasibility of CTP in AE liver lesions.

Material and Methods

CTP scanning was performed in 25 patients who had a total of 35 lesions identified as AE of the liver. Blood flow (BF), blood volume (BV), portal venous perfusion (PVP), arterial liver perfusion (ALP), and hepatic perfusion indexes (HPI) were computed for background liver parenchyma and each AE lesion.

Results

Significant differences were detected between perfusion values of the AE lesions and background liver tissue. The BV, BF, ALP, and PVP values for all components of the AE liver lesions were significantly lower than the normal liver parenchyma (p<0.01).

Conclusions

We suggest that perfusion imaging can be used in AE of the liver. Thus, the quantitative knowledge of perfusion parameters are obtained via CT perfusion imaging.

Optimized imaging of the midface and orbits

A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.

Assessment of bronchial and pulmonary blood supply in non-small cell lung cancer subtypes using computed tomography perfusion

OBJECTIVES

The aim of this study was to investigate the dual blood supply of non-small cell lung cancer (NSCLC) and its association with tumor subtype, size, and stage, using computed tomography perfusion (CTP).

MATERIALS AND METHODS

A total of 54 patients (median age, 65 years; range, 42-79 years; 15 women, 39 men) with suspected lung cancer underwent a CTP scan of the lung tumor. Pulmonary and bronchial vasculature regions of interest were used to calculate independently CTP parameters (blood flow [BF], blood volume [BV], and mean transit time [MTT]) of the tumor tissue. The mean and maximum pulmonary and bronchial perfusion indexes (PImean and PImax) were calculated. The tumoral volume and the largest tumoral diameter were assessed. Differences in CTP parameters and indexes among NSCLC subtypes, tumor stages and tumor dimensions were analyzed using non-parametric tests.

RESULTS

According to biopsy, 37 patients had NSCLC (22 adenocarcinomas [ACs], 8 squamous cell carcinomas [SCCs], 7 large-cell carcinomas [LCC]). The mean bronchial BF/pulmonary BF, bronchial BV/pulmonary BV, and bronchial MTT/pulmonary MTT was 41.2 ± 30.0/36.9 ± 24.2 mL/100 mL/min, 11.4 ± 9.7/10.4 ± 9.4 mL/100 mL, and 11.4 ± 4.3/14.9 ± 4.4 seconds, respectively. In general, higher bronchial BF than pulmonary BF was observed in NSCLC (P = 0.014). Using a tumoral volume cutoff of 3.5 cm, a significant difference in pulmonary PImax was found (P = 0.028). There was a significantly higher mean pulmonary BF in LCCs and SCCs compared with ACs (P = 0.018 and P = 0.044, respectively), whereas the mean bronchial BF was only significantly higher in LCCs compared with ACs (P = 0.024). Correspondingly, the PImax was significantly higher in LCCs and SCCs than in ACs (P = 0.001 for both). Differences between bronchial and pulmonary PImean and PImax among T stages and Union Internationale Contre le Cancer stages were not statistically significant (P values ranging from 0.691 to 0.753).

CONCLUSIONS

The known dual blood supply of NSCLC, which depends on tumor size and histological subtype, is reflected in CTP parameters, with parameters depending both on tumor size and histological subtype. This has to be accounted for when analyzing NSCLC with CTP.

Role of perfusion computed tomography in assessing submandibular gland radiochemotherapy-induced injury

OBJECTIVE

We aimed to detect changes in the volume and perfusion parameters of the submandibular glands during and after radiochemotherapy.

STUDY DESIGN

Twelve patients underwent computed tomography (CT) and perfusion CT before radiochemotherapy, after 40 Gy, after 70 Gy, and 3 months after radiochemotherapy. Submandibular gland volume, blood volume, permeability surface area product, and blood flow were quantified.

RESULTS

Submandibular gland volumes during and after therapy were significantly lower compared with the baseline value (P < .001). Blood volume, blood flow, and permeability surface area product values showed statistically significant reduction during and 3 months after therapy. A significant linear correlation was found between changes in submandibular gland volume and of the perfusion parameter blood volume in the period between baseline and 3 months after therapy (P = .012; RP = -0.697).

CONCLUSIONS

Changes in submandibular gland volume and dynamics of perfusion parameters imply that radiation-induced injury of submandibular glands develops early during radiochemotherapy.

Effect of increasing the sampling interval to 2 seconds on the radiation dose and accuracy of CT perfusion of the head and neck

PURPOSE

To evaluate the effect of increasing the sampling interval from 1 second (1 image per second) to 2 seconds (1 image every 2 seconds) on computed tomographic (CT) perfusion (CTP) of head and neck tumors.

MATERIALS AND METHODS

Twenty patients underwent CTP studies of head and neck tumors with images acquired in cine mode for 50 seconds using sampling interval of 1 second. Using deconvolution-based software, analysis of CTP was done with sampling interval of 1 second and then 2 seconds. Perfusion maps representing blood flow, blood volume, mean transit time, and permeability surface area product (PS) were obtained. Quantitative tumor CTP values were compared between the 2 sampling intervals. Two blinded radiologists compared the subjective quality of CTP maps using a 3-point scale between the 2 sampling intervals. Radiation dose parameters were recorded for the 2 sampling interval rates.

RESULTS

No significant differences were observed between the means of the 4 perfusion parameters generated using both sampling intervals; all P >0.05. The 95% limits of agreement between the 2 sampling intervals were -65.9 to 48.1) mL/min per 100 g for blood flow, -3.6 to 3.1 mL/100 g for blood volume, -2.9 to 3.8 seconds for mean transit time, and -10.0 to 12.5 mL/min per 100 g for PS. There was no significant difference between the subjective quality scores of CTP maps obtained using the 2 sampling intervals; all P > 0.05. Radiation dose was halved when sampling interval increased from 1 to 2 seconds.

CONCLUSIONS

Increasing the sampling interval rate to 1 image every 2 seconds does not compromise the image quality and has no significant effect on quantitative perfusion parameters of head and neck tumors. The radiation dose is halved.

Prediction of treatment response in head and neck carcinomas using IVIM-DWI: Evaluation of lymph node metastasis

PURPOSE

To obtain diffusion and microperfusion measures in lymph node metastases of head and neck squamous cell carcinomas (HNSCC) using intravoxel incoherent motion (IVIM) imaging. The obtained IVIM parameters were used to characterize lymph nodes in the staging phase and longitudinal follow-up was performed to evaluate the potential predictive value of these parameters considering therapy response.

METHODS

Fifteen patients with lymph node metastases of histologically confirmed locally advanced HNSCC were examined using diffusion weighted imaging (DWI) before a nonsurgical organ preserving therapy. DWI imaging was performed at 3T using eight different b-values ranging from 0 to 800s/mm(2). Using the IVIM-approach, the perfusion fraction f and the diffusion coefficient D were extracted using a biexponential fit. A follow-up period of 13.5 months was available for all patients. One patient with a macroscopically necrotic lymph node was excluded from analyses. A region of interest (ROI)-analysis was performed in all patients.

RESULTS

Locoregional failure (LRF) was present in 3 of 15 patients within 13.5 months follow-up. The initial f-value was significantly higher (p=0.01) in patients with LRF (14.5±0.6% vs. 7.7±2.6%) compared to patients with locoregional control (LRC). The initial diffusion coefficient D did not differ significantly (p=0.30) between the two groups (0.97±0.15×10(-3)mm(2)/s vs. 0.88±0.13×10(-3)mm(2)/s).

CONCLUSIONS

Our results indicate that a high initial perfusion fraction f in lymph nodes may predict poor treatment response in patients with HNSCC due to locoregional failure.

Perfusion CT of head and neck cancer

We aim to review the technique and clinical applications of perfusion CT (PCT) of head and neck cancer. The clinical value of PCT in the head and neck includes detection of head and neck squamous cell carcinoma (HNSCC) as it allows differentiation of HNSCC from normal muscles, demarcation of tumor boundaries and tumor local extension, evaluation of metastatic cervical lymph nodes as well as determination of the viable tumor portions as target for imaging-guided biopsy. PCT has been used for prediction of treatment outcome, differentiation between post-therapeutic changes and tumor recurrence as well as monitoring patient after radiotherapy and/or chemotherapy. PCT has a role in cervical lymphoma as it may help in detection of response to chemotherapy and early diagnosis of relapsing tumors.

Comparison of dual-energy CT-derived iodine content and iodine overlay of normal, inflammatory and metastatic squamous cell carcinoma cervical lymph nodes

OBJECTIVES

To evaluate whether dual-energy computed tomography (DECT)-derived iodine content and iodine overlay could differentiate between normal, inflammatory and metastatic squamous cell carcinoma (SCC) cervical lymph nodes.

METHODS

This study was approved by the institutional review board. Sixteen patients with normal lymph nodes, 20 patients with enlarged nodes draining deep cervical inflammations and 23 patients with pathologically proved metastatic SCC nodes who underwent contrast enhanced DECT were retrospectively identified. Iodine content and overlay of 36 normal, 43 inflammatory and 52 metastatic lymph nodes were calculated using circular regions of interest and compared among the three groups. A receiver operating characteristic (ROC) curve was used to determine the sensitivity and specificity of iodine content and overlay for diagnosis of metastatic nodes.

RESULTS

Iodine content (mg/ml) was significantly lower for metastatic lymph nodes (2.34 ± 0.45) than for normal (2.86 ± 0.37) and inflammatory (3.53 ± 0.56) lymph nodes, P < 0.0001. Iodine overlay (HU) was also significantly lower for metastatic lymph nodes (47 ± 11.6) than normal (57.4 ± 8.2) and inflammatory nodes (69.3 ± 11.5), P < 0.0001. The areas under the ROC curve for iodine content and iodine overlay were 0.923 and 0.896.

CONCLUSIONS

DECT-derived iodine content and overlay differ significantly among normal, inflammatory and metastatic SCC cervical lymph nodes.

KEY POINTS

• Derived iodine content can be calculated from contrast-enhanced dual-energy CT. • Derived iodine content and iodine overlay could help characterise cervical lymph nodes. • Iodine parameters were significantly lower in metastatic lymph nodes than normal/inflammatory lymph nodes. • Iodine content appears more sensitive than iodine overlay for lymph node characterisation.

Does volume perfusion computed tomography enable differentiation of metastatic and non-metastatic mediastinal lymph nodes in lung cancer patients? A feasibility study

OBJECTIVES

To compare the perfusion characteristics of mediastinal lymph node metastases with those of non-metastatic nodes in patients with newly diagnosed lung cancer using volume perfusion computed tomography (VPCT).

MATERIALS AND METHODS

Between January 2010 and October 2011, 101 patients with histologically confirmed, untreated lung cancer received a 40-s VPCT of the tumor bulk; 32/101 patients had evident hilar/mediastinal metastatic disease and 17/101 patients had proven non-metastasized lymph nodes within the VPCT scan range. Validation or exclusion of metastatic node involvement was proven by mediastinoscopy, biopsy, positron emission tomography imaging and/or unequivocal volume dynamics on follow-up computed tomography. A total of 45 metastases and 23 non-metastatic lymph nodes were found within the scan range and subsequently evaluated. Blood flow (BF), blood volume (BV) and K(trans) were determined. Tumor volume was recorded as whole tumor volume.

RESULTS

In a comparison between metastatic and non-metastatic lymph nodes, we controlled for age, lymph node volume, lung tumor volume, lung tumor location, and histologic type effects and found no significant differences with respect to BF, BV, K(trans) or heterogeneity in nodal perfusion (P > 0.05, respectively), even after adjusting lymph node perfusion values to the perfusion parameters of the primary tumor (P > 0.05, respectively). Metastatic lymph node volume had a significant increasing effect on perfusion heterogeneity (P < 0.05, respectively) and BV in the primary was a highly significant factor for BV in metastatic disease (P < 0.001).

CONCLUSION

Perfusion characteristics of mediastinal metastatic and non-metastatic lymph nodes in untreated lung cancer show considerable overlap, so that a reliable differentiation via VPCT is not possible.

Cervical lymph node evaluation and diagnosis

This article discusses the rationale for imaging cervical lymph nodes and reviews nodal anatomy and common drainage patterns, imaging features of pathologic lymph nodes, and the advantages of various imaging modalities available for evaluation and diagnosis of the lymph nodes.

Human papillomavirus, p16, and epidermal growth factor receptor biomarkers and CT perfusion values in head and neck squamous cell carcinoma

BACKGROUND AND PURPOSE

Head and neck squamous cell carcinoma tumors positive for laboratory biomarkers hrHPV and p16 and negative for EGFR often respond better to nonsurgical organ-preservation therapy than hrHPV-negative, p16-negative, and EGFR overexpressing tumors. CTP has been shown to distinguish which locally advanced head and neck squamous cell carcinomas will respond to induction chemotherapy or chemoradiation. Our purpose was to determine whether a relationship exists between CTP measures and the expression of these laboratory biomarkers, because both appear to separate head and neck squamous cell carcinoma tumors into similar groups.

MATERIALS AND METHODS

We conducted an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective review of head and neck CTP in 25 patients with locally advanced head and neck squamous cell carcinoma who had signed informed consent. Eight women and 17 men, 41-80 years of age, constituted a pretreatment group of 18 patients and a palliative group of 7 patients. Tumor biopsy samples were analyzed for overexpression of hrHPV, p16, and EGFR. The hrHPV, p16, and EGFR status of the tumors was correlated with CTP parameters (MTT, BV, BF, CP) by using the Wilcoxon evaluation and Fischer exact test.

RESULTS

There were significantly lower CP values in pretreatment tumors overexpressing EGFR (P = .04). CP values ≤17.23 were significantly correlated with EGFR overexpression (P = .015). A trend toward higher CP values was present in hrHPV-positive and p16-overexpressing pretreatment tumors (P = .14).

CONCLUSIONS

A significant correlation exists between CTP measures and EGFR overexpression in head and neck squamous cell carcinomas, suggesting an association between certain imaging findings and molecular biomarkers. These results may be related to a tumor cell survival mechanism linking perfusion and biomarker expression.

Diagnosis and treatment of recurrent laryngeal cancer following initial nonsurgical therapy

Surgery is the preferred modality for curative treatment of recurrent laryngeal cancer after failure of nonsurgical treatments. Patients with initial early-stage cancer experiencing recurrence following radiotherapy often have more advanced-stage tumors by the time the recurrence is recognized. About one third of such recurrent cancers are suitable for conservation surgery. Endoscopic resection with the CO(2) laser or open partial laryngectomy (partial vertical, supracricoid, or supraglottic laryngectomies) have been used. The outcomes of conservation surgery appear better than those after total laryngectomy, because of selection bias. Transoral laser surgery is currently used more frequently than open partial laryngectomy for treatment of early-stage recurrence, with outcomes equivalent to open surgery but with less associated morbidity. Laser surgery has also been employed for selective cases of advanced recurrent disease, but patient selection and expertise are required for application of this modality to rT3 tumors. In general, conservation laryngeal surgery is a safe and effective treatment for localized recurrences after radiotherapy for early-stage glottic cancer. Recurrent advanced-stage cancers should generally be treated by total laryngectomy.

Biologic imaging of head and neck cancer: the present and the future

While anatomic imaging (CT and MR imaging) of HNC is focused on diagnosing and/or characterizing the disease, defining its local extent, and evaluating distant spread, accurate assessment of the biologic status of the cancer (cellularity, growth rate, response to nonsurgical chemoradiation therapy, and so forth) can be invaluable for prognostication, planning therapy, and follow-up of lesions after therapy. The combination of anatomic and biologic imaging techniques can thus provide a more comprehensive evaluation of the patient. The purpose of this work was to review the present and future clinical applications of advanced biologic imaging techniques in HNC evaluation and management. As part of the biologic imaging array, we discuss MR spectroscopy, diffusion and perfusion MR imaging, CTP, and FDG-PET scanning and conclude with exciting developments that hold promise in assessment of tumor hypoxia and neoangiogenesis.

Squamous cell carcinoma of the head and neck-The role of diffusion and perfusion imaging in tumor recurrence and follow-up

Computed tomography and magnetic resonance imaging-based techniques of functional imaging are proven to be sensitive and reliable tools for detection and staging of head and neck cancer. These new techniques enable to visualize and differentiate subtle pathologic changes before they become evident on standard cross-sectional images. However, it is their role in evaluating possible recurrence and estimation of treatment response that holds the biggest promise. This article describes the role and usefulness of diffusion and perfusion in detecting recurrence and follow-up in patients with head and neck squamous cell carcinoma.

Role of perfusion magnetic resonance imaging in cervical lymphadenopathy

PURPOSE

To assess the role of perfusion magnetic resonance (MR) imaging in patients with cervical lymphadenopathy.

MATERIALS AND METHODS

Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging was performed on 45 cervical lymph nodes after a bolus injection of gadolinium-DTPA (0.1 mmol/kg body weight). Time signal intensity curve was created and dynamic susceptibility contrast (DSC) percentage of the lymph nodes was calculated. Receiver operating characteristic curve analysis was used to investigate whether DSC percentage could aid in the characterization of cervical lymphadenopathy.

RESULTS

The mean (SD) DSC percentage of malignant nodes (44.8% [6.2%]) was significantly different (P = 0.001) from that of benign nodes (28.8% [4.8%]). The mean (SD) DSC percentage of metastatic nodes (48.72% [2.4%]) was significantly different (P = 0.001) than that of lymphoma (37.09% [3.5%]). The DSC percentage threshold value used for differentiating malignant from benign nodes and metastatic from lymphomatous nodes were 34.3% and 43.5%, with areas under the curve of 0.95 and 0.97, respectively.

CONCLUSIONS

Perfusion MR imaging is a noninvasive promising method that can be used for differentiation of malignant from benign cervical lymph nodes, and it helps in the characterization of malignant cervical lymphadenopathy.

Tracer kinetic modelling of tumour angiogenesis based on dynamic contrast-enhanced CT and MRI measurements

PURPOSE

Technical developments in both magnetic resonance imaging (MRI) and computed tomography (CT) have helped to reduce scan times and expedited the development of dynamic contrast-enhanced (DCE) imaging techniques. Since the temporal change of the image signal following the administration of a diffusible, extracellular contrast agent (CA) is related to the local blood supply and the extravasation of the CA into the interstitial space, DCE imaging can be used to assess tissue microvasculature and microcirculation. It is the aim of this review to summarize the biophysical and tracer kinetic principles underlying this emerging imaging technique offering great potential for non-invasive characterization of tumour angiogenesis.

METHODS

In the first part, the relevant contrast mechanisms are presented that form the basis to relate signal variations measured by serial CT and MRI to local tissue concentrations of the administered CA. In the second part, the concepts most widely used for tracer kinetic modelling of concentration-time courses derived from measured DCE image data sets are described in a consistent and unified manner to highlight their particular structure and assumptions as well as the relationships among them. Finally, the concepts presented are exemplified by the analysis of representative DCE data as well as discussed with respect to present and future applications in cancer diagnosis and therapy.

RESULTS

Depending on the specific protocol used for the acquisition of DCE image data and the particular model applied for tracer kinetic analysis of the derived concentration-time courses, different aspects of tumour angiogenesis can be quantified in terms of well-defined physiological tissue parameters.

CONCLUSIONS

DCE imaging offers promising prospects for improved tumour diagnosis, individualization of cancer treatment as well as the evaluation of novel therapeutic concepts in preclinical and early-stage clinical trials.

The role of perfusion CT as a follow-up modality after transcatheter arterial chemoembolization: an experimental study in a rabbit model

OBJECTIVES

To prospectively evaluate the feasibility of perfusion CT as a follow-up modality after transcatheter arterial chemoembolization (TACE) and to compare these findings with those of histopathology as the reference standard in a VX2 tumor rabbit model.

MATERIALS AND METHODS

VX2 carcinoma tumors were implanted into the liver of 20 rabbits 3 weeks prior to TACE. Perfusion CT was performed prior to TACE and 1- and 4-week after TACE. After obtaining perfusion index maps on perfusion CT, 2 radiologists measured the parametric perfusion indices of blood flow (BF), blood volume (BV), mean transit time (MTT), permeability of the capillary vessel surface (PS), and hepatic arterial fraction (HAF) of primary tumors on pre-TACE perfusion CT, chemoembolized primary tumors on 1-week perfusion CT, and recurred tumors on 4-week perfusion CT. The normal liver parenchyma indices were also recorded. In addition, the radiologists investigated the presence of a recurred tumor adjacent to the chemoembolized area on perfusion index maps of 4-week CT images. The areas of higher hepatic blood flow (HBF), hepatic blood volume (HBV), PS, and HAF, and lower MTT on 4-week perfusion CT than the normal liver parenchyma and the identical area on 1-week perfusion CT were considered as recurred tumors. Histopathology revealed the presence of a recurred tumor, and mean vessel density (MVD) was determined by immunochemical staining for CD31. CT perfusion indices were compared by use of the t test. Comparisons were made for the primary tumor versus normal liver parenchyma on pre-TACE CT, the primary tumor on pre-TACE CT versus the chemoembolized tumor on 1-week CT, the recurred tumor on 4-week CT versus the identical area on 1-week CT, and the primary tumor on pre-TACE CT versus the recurred tumor on 4-week CT. For the detection of recurred tumors, the sensitivity and specificity for 4-week perfusion CT were calculated. Correlation analysis between the recurred tumor perfusion indices and the MVD of the corresponding tumor region was performed. Among 20 rabbits, 6 were excluded from the analysis, and results were based on 14 rabbits.

RESULTS

Recurred tumors were histologically proven in 8 of 14 rabbits (57.1%). The BF, BV, PS, and HAF indices of primary tumors were significantly higher, whereas the MTT was significantly lower than that of the normal liver parenchyma on pre-TACE perfusion CT and that of chemoembolized areas on 1-week perfusion CT (P < 0.05). In addition, recurred tumors also showed significantly higher BF, BV, PS, and HAF, and lower MTT indices than the identical areas on 1-week perfusion CT (P < 0.05). The perfusion indices of recurred tumors were not significantly different from the indices of primary tumors (P > 0.05). Both sensitivity and specificity were 100% for 4-week perfusion CT. There were significant positive correlations between BF (r = 0.947), BV (r = 0.758), PS (r = 0.759), HAF (r = 0.955), and MVD in recurred tumors, and a significant inverse correlation between MTT (r = -0.782) and MVD was observed (P < 0.05).

CONCLUSIONS

We believe that perfusion CT is a feasible alternative modality for the successful early response assessment and early detection of a marginally recurred tumor after TACE. However, perfusion CT has limitations for the prediction of tumor recurrence after TACE.

An exploratory pilot study into the association between microcirculatory parameters derived by MRI-based pharmacokinetic analysis and glucose utilization estimated by PET-CT imaging in head and neck cancer

OBJECTIVES

To examine the feasibility of deriving quantitative microcirculatory parameters and to investigate the relationship between vascular and metabolic characteristics of head and neck tumours in vivo, using dynamic contrast-enhanced (DCE) MRI and fluorodeoxyglucose (FDG) PET imaging.

METHODS

Twenty-seven patients with primary squamous cell carcinoma (SCCA) underwent DCE-MRI and combined PET/CT imaging. DCE-MRI data were post-processed by using commercially available software. Transfer constant (K (trans)), extravascular extracellular blood volume (v (e)), transfer constant from the extracellular extravascular space to plasma (k (ep)) and iAUC (initial area under the signal intensity-time curve) were calculated. 3D static PET data were acquired and standardised uptake values (SUV) calculated.

RESULTS

All microcirculatory parameters in tumours were higher than in normal muscle tissue (P ≤ 0.0019). Significant correlations were shown between k (ep) and K (trans) (ρ = 0.77), v (e) and k (ep) (ρ = -0.7), and iAUC and v (e) (ρ = 0.53). Significant correlations were observed for SUV(mean) and v (e) as well as iAUC (ρ = 0.42 and ρ = 0.66, respectively). SUV(max) was significantly correlated with iAUC (ρ = 0.69).

CONCLUSIONS

The demonstrated relationships between vascular and metabolic characteristics of primary SCCA imply a complex interaction between vascular delivery characteristics and tumour metabolism. The lack of correlation between SUV and K (trans)/k (ep) suggests that both diagnostic techniques may provide complementary information.

Whole tumour quantitative measurement of first-pass perfusion of oesophageal squamous cell carcinoma using 64-row multidetector computed tomography: correlation with microvessel density

PURPOSE

To assess correlations between whole tumour first-pass perfusion parameters obtained with 64-row multidetector computed tomography (MDCT), and microvessel density (MVD) in oesophageal squamous cell carcinoma.

MATERIALS AND METHODS

Thirty-one consecutive patients with surgically confirmed oesophageal squamous cell carcinomas were enrolled into our study. All the patients underwent whole tumour first-pass perfusion scan with 64-row MDCT. Perfusion parameters, including perfusion (PF), peak enhanced density (PED), blood volume (BV), and time to peak (TTP) were measured using Philips perfusion software. Postoperative tumour specimens were assessed for MVD. Pearson correlation coefficient tests were performed to determine correlations between each perfusion parameter and MVD.

RESULTS

Mean values for PF, PED, BV and TTP of the whole tumour were 28.85 ± 20.29 ml/min/ml, 23.16 ± 8.09 HU, 12.13 ± 5.21 ml/100g, and 35.05 ± 13.85 s, respectively. Mean MVD in whole tumour at magnification (×200) was 15.75 ± 4.34 microvessel/tumour sample (vessels/0.723 mm(2)). PED and BV were correlated with MVD (r=0.651 and r=0.977, respectively, all p<0.05). However, PF and TTP were not correlated with MVD (r=0.070 and r=0.100, respectively, all p>0.05).

CONCLUSION

The BV value of first-pass perfusion CT could reflect MVD in oesophageal squamous cell carcinoma, and can be an indicator for evaluating the tumour angiogenesis.

Cancer of the oral cavity and oropharynx

Tumours in the oral cavity and oropharynx differ in presentation and prognosis and the detection of spread of tumour from one subsite to another is essential for the T-staging. This article reviews the anatomy and describes the pattern of spread of different cancers arising in the oral cavity and oropharynx; the imaging findings on computerized tomography and magnetic resonance imaging are also described. Brief mention is made on the role of newer imaging modalities such as [¹⁸F]fluorodeoxyglucose-positron emission tomography/computed tomography, perfusion studies and diffusion-weighted magnetic resonance imaging.

Changes in perfusion CT of advanced squamous cell carcinoma of the head and neck treated during the course of concomitant chemoradiotherapy

BACKGROUND AND PURPOSE

Concomitant chemoradiation is a promising therapy for the treatment of locoregionally advanced head and neck carcinoma. The purpose of this study was to prospectively evaluate early changes in primary tumor perfusion parameters during concomitant cisplatin-based chemoradiotherapy of locoregionally advanced SCCHN and to evaluate their predictive value for response of the primary tumor to therapy.

MATERIALS AND METHODS

Twenty patients with locoregionally advanced SCCHN underwent perfusion CT scans before therapy and after completion of 40 Gy and 70 Gy of chemoradiotherapy. BF, BV, MTT, and PS of primary tumors were quantified. Differences in perfusion and tumor volume values during the therapy as well as between responders and nonresponders were analyzed, and ROC curves were used to assess predictive value of the baseline and follow-up functional parameters.

RESULTS

The tumor volumes at 40 Gy and at 70 Gy were significantly lower compared with baseline values (P = .014 and P = .007). In the 6 nonresponders, measurements after 40 Gy showed a nonsignificant trend of increased BF, BV, and PS values compared with the baseline values (P = .06). In 14 responders, a significant reduction of BF values was recorded after 40 Gy (P = .04) and after 70 Gy (P = .01). In responders, BV values showed a reduction after 40 Gy followed by a plateau after 70 Gy (P = .04), whereas in nonresponders there was a nonsignificant elevation of the BV. Baseline BV predicted short-term tumor response with a sensitivity of 60% and specificity of 100% (P = .01). After completion of 40 Gy of concomitant chemoradiation BV was a more significant predictor than were BF and MTT.

CONCLUSIONS

The results suggest that in advanced SCCHN the perfusion CT monitoring might be of predictive value for identifying tumors that may respond to cisplatin-based chemoradiotherapy.

CT perfusion in oncology: how to do it

Robust technique and accurate data analysis are required for reliable computed tomography perfusion (CTp) imaging. Multislice CT is required for high temporal resolution scanning; 16-slice (or 64-slice) scanners are preferred for adequate volume coverage. After tumour localization, the volume of CTp imaging has to be positioned to include the maximum visible area of the tumour and an adequate arterial vessel. Dynamic scans at high temporal resolution (at least 1-s gantry rotation time) are performed to visualize the first pass of contrast agent within the tumour; repeated scans with low temporal resolution can be planned for late enhancement assessment. A short bolus of conventional iodinated contrast agent, preferably with high iodine concentration, is power injected at a high flow rate (>4 ml/s) in the antecubital vein. The breath-hold technique is required for CTp imaging of the chest and upper abdomen to avoid respiratory motion; free breathing is adequate for CTp imaging of the head, neck and pelvis. Using dedicated software, a region of interest (ROI) has to be placed in an adequate artery (as arterial input) to obtain density–time curves; according to different kinetic models, colour maps of different CTp parameters are generated and generally overlaid on CT images. Additional ROIs can be positioned in the tumour, and in all other parts of the CTp volume, to obtain the values of the CTp parameters within the ROI.

Perfusion CT in squamous cell carcinoma of the upper aerodigestive tract: long-term predictive value of baseline perfusion CT measurements

BACKGROUND AND PURPOSE

PCT studies hold short-term predictive value in patients treated with chemoradiotherapy. Our aim was to examine the long-term predictive value of baseline PCT studies for local tumor control and overall survival in SCCA of the upper aerodigestive tract treated with chemoradiotherapy.

MATERIALS AND METHODS

Eighty-four patients with advanced SCCA underwent PCT followed by concomitant chemoradiation. The acquired perfusion maps represented BF, BV, MTT, and PS. Visual analysis of the parametric maps for identification of tumor perfusion patterns was conducted. ROC curves, t tests, and Kaplan-Meier survival curves were plotted for local disease control and overall survival.

RESULTS

The median time of local tumor control was 24 months. The BF and PS values were significantly higher in patients who had no recurrence than in those with local failure (P < or = .02). The BF and PS were predictive (P < or = .0006) but BV and MTT held no significant predictive values for local tumor control. The patients with high BF and PS had a longer local tumor control than the patients with hypoperfused tumors (P = .0007). A visually detected BF-BV mismatch had a sensitivity/specificity of 63%/66% (P = .03) and 59%/69% (P = .03) for local tumor control and OS, respectively. Patients without mismatch lived significantly longer than patients with mismatch (P = .01).

CONCLUSIONS

BF, PS, and mismatch of BF-BV are significant predictors of local tumor control after chemoradiation in SCCA of the upper aerodigestive tract.