Biologic Imaging of Head and Neck Cancer: The Present and the Future

Abstract

SUMMARY: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.ABBREVIATIONS: ADC ϭ apparent diffusion coefficient; BF ϭ blood flow; BV ϭ blood volume; Cho ϭ choline; Cr ϭ creatine; CP ϭ capillary permeability; CTP ϭ CT perfusion; DCE ϭ dynamic contrast-enhanced; DTI ϭ diffusion tensor imaging; DWI ϭ diffusion-weighted MR imaging;18 Fϭ fluorine 18; FMISO ϭ fluoromisonidazole; FDG-PET ϭ fluorodeoxyglucose-positron-emission tomography; FLT ϭ fluorothymidine; GTV ϭ gross tumor volume; HNC ϭ head and neck cancer; K trans ϭ average contrast transfer coefficient; MTT ϭ mean transit time; MVD ϭ mean vessel attenuation; PET ϭ positron-emission tomography; PRM ϭ parametric response map; RGD ϭ arginine-glycine-aspartic acid H NC accounts for approximately 3%-5% of all new cancer diagnoses in the United States with 40,000 new cases diagnosed each year.1 The present day approach of one-for-all standardized chemoradiation regimens has shown higher locoregional recurrence rates in a sizable proportion of patients, necessitating the development of advanced neuroimaging techniques that can provide biologic information about a cancer and help in identifying cancers potentially unresponsive to standard chemoradiation regimens. If this approach succeeds, these potentially unresponsive cancers can then be treated with other measures, such as increased radiation doses or surgery, which would have a higher chance of achieving success.When a patient presents with a clinically suspicious head and neck malignancy, the clinician is primarily interested in confirming the suspicion with imaging and in also knowing about the disease extent, locoregional spread, and metastasis. While conventional CT or MR imaging can provide answers to most questions, it falls short in other areas such as detection of metastatic disease in small lymph nodes or prediction of response of a cancer to chemoradiation. Also, when a cancer is treated and the patient presents for follow-up with a mass, it can become difficult in most instances to characterize the lesion by using conventional imaging and typically biopsy is sought to solve the mystery. Hence, the advent of biologic neuroimaging modalities t...

Usefulness of Pseudocontinuous Arterial Spin-Labeling for the Assessment of Patients with Head and Neck Squamous Cell Carcinoma by Measuring Tumor Blood Flow in the Pretreatment and Early Treatment Period

“…A past reported review article introduced several studies that describe the use of pretreatment TBF measured by a dynamic contrast-enhanced perfusion technique for assessments of the prognosis of patients undergoing chemoradiotherapy. 23 Most of these studies concluded that lower pretreatment TBF values indicated a poor prognosis. Our present findings showed the same trend as these previous reports.…”

Advanced diffusion models in head and neck squamous cell carcinoma patients: Goodness of fit, relationships among diffusion parameters and comparison with dynamic contrast-enhanced perfusion

“…The apparent diffusion coefficient (ADC), calculated using the mono-exponential decay function of DWI signal intensity with two or more b-values, has been reported to be useful in head and neck squamous cell carcinoma (HNSCC) cases for differentiating benign and malignant tissues, and to assess therapeutic efficacy and predict treatment outcomes [4,5]. Although the biological characteristics of sinonasal and pharynx SCC are somewhat different and these two types of HNSCC also slightly differ in regard to characteristics such as causes, risk factors, frequency of lymph node and distant metastases, and treatment strategies, the utility of the ADC was reported for both types of HNSCC [4][5][6].…”

“…Although the biological characteristics of sinonasal and pharynx SCC are somewhat different and these two types of HNSCC also slightly differ in regard to characteristics such as causes, risk factors, frequency of lymph node and distant metastases, and treatment strategies, the utility of the ADC was reported for both types of HNSCC [4][5][6]. However, the water diffusion behavior in cancer tissues is complicated, and it is difficult to explain the water diffusion behavior in a completely free water diffusion model using the mono-exponential decay function.…”

“…(1) to (5). In tri-exponential fitting of Eq (3), the sum of the three parameters f 1 ,f 2 and f 3 became 1.…”

Intravoxel incoherent motion diffusion-weighted imaging in head and neck squamous cell carcinoma: Assessment of perfusion-related parameters compared to dynamic contrast-enhanced MRI

“…Tumor diffusion and perfusion are important biological parameters for the assessment of head and neck squamous cell carcinoma (HNSCC), and their usefulness has been described for the first assessments for treatment planning, the early detection of treatment effect, and post-treatment assessments to detect the presence of residual tumor [1]. Estimations of tumor perfusion have been performed mainly by the dynamic contrast-enhanced (DCE) technique [2,3].…”