Magnetic resonance imaging for prospective assessment of local recurrence of non-small cell lung cancer after stereotactic body radiation therapy.

OBJECTIVES: To evaluate multi-parametric MRI for distinguishing stereotactic body radiation therapy (SBRT) induced pulmonary fibrosis from local recurrence (LR). MATERIALS AND METHODS: SBRT treated non-small cell lung cancer (NSCLC) patients suspected of LR by conventional imaging underwent MRI: T2 weighted, diffusion weighted imaging, dynamic contrast enhancement (DCE) with a 5-minute delayed sequence. MRI was reported as high or low suspicion of LR. Follow-up imaging ≥12 months or biopsy defined LR status as proven LR, no-LR or not-verified. RESULTS: MRI was performed between 10/2017 and 12/2021, at a median interval of 22.5 (interquartile range 10.5-32.75) months after SBRT. Of the 20 lesions in 18 patients: 4 had proven LR, 10 did not have LR and 6 were not verified for LR due to subsequent additional local and/or systemic therapy. MRI correctly identified as high suspicion LR in all proven LR lesions and low suspicion LR in all confirmed no-LR lesions. All proven LR lesions (4/4) showed heterogeneous enhancement and heterogeneous T2 signal, as compared to the proven no-LR lesions in which 7/10 had homogeneous enhancement and homogeneous T2 signal. DCE kinetic curves could not predict LR status. Although lower apparent diffusion coefficient (ADC) values were seen in proven LR lesions, no absolute cut-off ADC value could determine LR status. CONCLUSION: In this pilot study of NSCLC patients after SBRT, multi-parametric chest MRI was able to correctly determine LR status, with no single parameter being diagnostic by itself. Further studies are warranted.

Multimodality imaging evaluation of esophageal cancer: staging, therapy assessment, and complications.

Esophageal cancer is among the leading causes of cancer-related deaths worldwide. The management of patients with esophageal cancer is determined to a large extent by patient performance status, location of the primary cancer, and stage of disease at presentation. Multimodality regimens combining neoadjuvant chemotherapy and/or radiotherapy followed by surgery have been increasingly used in suitable candidates with locally advanced cancer. There is substantial morbidity and mortality associated with this treatment strategy, which makes appropriate patient selection important. Endoscopic esophageal ultrasound is the optimal modality to evaluate the local extent of the primary tumor and diagnose locoregional nodal metastasis. Computed tomography is more useful in detecting distant nodal and systemic metastasis. Positron emission tomography/CT is increasingly being used in patient management and improves the accuracy of staging, particularly in the detection of distant nodal and systemic metastatic disease. In this article, we review the role of imaging in the staging, assessment of therapeutic response, and detection of recurrent disease, as well as the evaluation of therapeutic complications in patients with esophageal cancer.

Positron emission tomography/computed tomography in lung cancer staging, prognosis, and assessment of therapeutic response.

Positron emission tomography (PET)/computed tomographic scanning, using 18F-2-deoxy-D-glucose, complements conventional imaging evaluation of patients with lung cancer. The strength of PET scanning lies in the detection of nodal and extrathoracic metastases. PET scanning is also currently being studied in the assessment of prognosis and therapeutic response and has the potential to alter management of oncologic patients. This review will discuss the role of PET/computed tomographic scanning in the diagnosis, staging, and evaluation of prognosis and treatment response in patients with lung cancer.

Imaging of non-small cell lung cancer of the superior sulcus: part 2: initial staging and assessment of resectability and therapeutic response.

Imaging plays a crucial role in the diagnosis and staging of superior sulcus tumors, assessment of their resectability, determination of the optimal approach to disease management, and evaluation of the response to therapy. Computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET)/CT contribute important and complementary information. Whereas CT is optimal for depicting bone erosion and for staging of intrathoracic disease, MR imaging is superior for evaluating tumor extension to the intervertebral neural foramina, the spinal cord, and the brachial plexus, primarily because of the higher contrast resolution and multiplanar capability available with MR imaging technology. Use of PET/CT enables the detection of unsuspected nodal and distant metastases. However, imaging has only limited usefulness for evaluating the response of a tumor to induction therapy and detecting local recurrence, and surgical biopsy often is necessary to verify the results of therapy.

Preoperative chemo-radiation-induced ulceration in patients with esophageal cancer: a confounding factor in tumor response assessment in integrated computed tomographic-positron emission tomographic imaging.

HYPOTHESIS: Positron emission tomography can be useful in predicting response of esophageal cancer after preoperative chemo-radiation therapy (CRT). We evaluated the use of integrated computed tomography (CT)-PET among patients with esophageal cancer being considered for resection after CRT. METHODS: Three reviewers blinded to clinical and pathologic staging retrospectively reviewed the CT-PET scans of patients with esophageal cancer after preoperative CRT who underwent esophagectomy. [F]-fluoro-2-deoxy-D-glucose uptake for residual malignancy was determined by visual analysis and semi-quantitatively when standardized uptake value (SUV) was > or =4. RESULTS: Forty-two patients underwent esophageal resection. Using visual analysis, CT-PET had a sensitivity of 47% and specificity of 58% in detecting residual malignancy. Using semi-quantitative analysis, 19 patients had a SUV > or =4 in the region of the primary esophageal tumor and were interpreted as having residual malignancy (sensitivity 43%, specificity 50%). Of these 19, six had complete pathologic response to CRT. These false-positive results, due to therapy-induced ulceration detected at endoscopy, limit the use of CT-PET alone in detecting residual malignancy. Similarly, sensitivity (25%) and specificity (73%) of endoscopy/biopsy in detecting residual malignancy were poor. However, the accuracy of CT-PET in detecting residual malignancy was improved when combined with endoscopic findings. In the absence of ulceration at endoscopy, 8 of 8 patients with SUV > or =4 after chemo-radiation had residual malignancy at surgery. CONCLUSIONS: CRT-induced ulceration results in false-positive results on CT-PET and precludes accurate detection of residual esophageal tumor. However, CT-PET in combination with endoscopy is useful in identifying patients with a high risk of residual tumor post-CRT.

Bronchioalveolar cell carcinoma: radiologic appearance and dilemmas in the assessment of response.

Bronchioalveolar cell carcinomas (BACs), a subset of primary lung adenocarcinomas, are uncommon. Histologically, they are a diverse group of malignancies. The diagnosis is restricted to adenocarcinomas that grow in a lepidic manner and that have no stromal, vascular, or pleural invasion. Their histologic diversity leads to varied radiologic manifestations that are often indistinguishable from those of other primary non-small-cell lung cancers (NSCLC). However, typical manifestations, many of which can be attributed to lepidic growth, have been reported. Radiologic manifestations include a solitary peripheral pulmonary nodule, airspace disease, and multiple nodules and a combination of these findings can be present in a single patient. The most common manifestation, a solitary pulmonary nodule, is usually indistinguishable from other primary NSCLC. However, pseudocavitation and air bronchograms within the nodule can be useful in suggesting the correct diagnosis. In addition to aiding in the diagnosis of BAC, radiologic imaging is an important component in the evaluation of the therapeutic efficacy of treatment; serial measurements of tumor size before and after treatment are commonly used to assess response. However, BACs that are consolidative or ground-glass in nature present challenges in tumor-response determination. Other imaging modalities, such as positron emission tomography scanning, may prove helpful in assessing the metabolic response to therapy but have yet to be proven effective.

Imaging to optimally stage lung cancer: conventional modalities and PET/CT.

Accurately staging patients with lung cancer is important in determining treatment options and prognoses. Staging allows the distinction of patients who are candidates for surgical resection from those with inoperable disease who may be treated with chemotherapy and/or radiation therapy. Conventional imaging plays an essential role in the noninvasive and invasive methods of the evaluation and staging of patients with non-small-cell lung cancer (NSCLC). Imaging modalities used for staging include chest radiography, chest computed tomography (CT), abdominal CT, brain CT or magnetic resonance imaging, bone scans, and (18)F-2-deoxy-d-glucose positron emission tomography (PET). Recently, PET/CT, the integration of the functional data of PET with the anatomic data of CT, has emerged as a modality to potentially change the way patients are evaluated. This article reviews current recommendations regarding the staging of patients with NSCLC and addresses the role of PET/CT.

Interobserver and intraobserver variability in measurement of non-small-cell carcinoma lung lesions: implications for assessment of tumor response.

PURPOSE: Response of solid malignancies to therapy is usually determined by serial measurements of tumor size. The purpose of our study was to assess the consistency of measurements performed by readers evaluating lung tumors. MATERIALS AND METHODS: The study group was composed of 33 patients with lung tumors more than 1.5 cm. Bidimensional (BD) and unidimensional (UD) measurements were performed on computed tomography (CT) scans according to the World Health Organization (WHO) criteria and the Response Evaluation Criteria in Solid Tumors (RECIST), respectively. Measurements were performed independently by five thoracic radiologists using printed film and were repeated after 5 to 7 days. Inter- and intraobserver measurement variations were estimated through statistical modeling. RESULTS: There were 40 tumors with an average size of 1.8 to 8.0 cm (mean, 4.1 cm). Analysis of variance showed a significant difference (P <.05) among readers and among the measured nodules for UD and BD measurements. Interobserver misclassification rates were more than intraobserver misclassification rates using either progressive disease or response criteria. The probability of misclassifying a tumor with the WHO criteria or RECIST was greatest with interobserver measurements when criteria for progression (43% BD, 30% UD) were used and lowest with intraobserver measurements when criteria for response (2.5% BD, 3.0% UD) were used. In addition, interobserver misclassification rates were more than intraobserver misclassification rates for both regular and irregular tumors. CONCLUSION: Measurements of lung tumor size on CT scans are often inconsistent and can lead to an incorrect interpretation of tumor response. Consistency can be improved if the same reader performs serial measurements for any one patient.