Secondary Lung Malignancies Research Articles

CT-Guided Interstitial Brachytherapy of Primary and Secondary Lung Malignancies

CT-guided interstitial brachytherapy of primary lung malignancies and pulmonary metastases represents a novel interventional technique, combining conventional high-dose-rate (HDR) iridium-192 (192Ir) brachytherapy with modern CT guidance for applicator positioning and computer-aided 3-D radiation treatment planning. The purpose of this study was to assess safety and efficacy of this technique. 30 patients with 83 primary or secondary lung malignancies were recruited in a prospective nonrandomized trial (Table 1). After catheter positioning under CT fluoroscopy, a spiral CT was acquired for treatment planning (Figure 1). All but two patients received a defined single dose (coverage > 99%) of at least 20 Gy from a 192Ir source in HDR technique. Adverse effects were nausea (n = 3, 6%), minor (n = 6, 12%) and one major pneumothorax (2%). Post intervention, no changes of vital capacity and forced expiratory volume could be detected. The median follow-up period was 9 months (1–21 months) with a local tumor control of 91% at 12 months (Figure 2). CT-guided interstitial brachytherapy proved to be safe and effective for the treatment of primary and secondary lung malignancies.

Percutaneous radiofrequency ablation of lung tumours: Results in first 100 consecutive patients

7714 Background: Treatment modalities for patients with primary and secondary lung malignancies who are not surgical candidates are limited. Radiofrequency ablation is a minimally invasive, lung sparing therapeutic alternative that may provide local disease control for these patients. The study reported our experience with first 100 consecutive patients who underwent radiofrequency ablation of their lung tumours. Methods: From November 2000 to December 2006, the clinical and treatment-related information regarding the 100 consecutive patients (58 males, mean age of 65 years) with 240 lung tumours treated by radiofrequency ablation were collected prospectively. Radiofrequency ablation was performed percutaneously under CT guidance with local anaethesiologic assistance and conscious sedation using a RITA Starbust XL electrode. The patients were hospitalized overnight and followed at one week, one month and then every three months with CT to evaluate treatment outcome and complications. Results: Five patients had primary lung carcinoma while the remaining patients had pulmonary metastases from extra-thoracic malignancies, with colorectal cancer being the most common primary site (68%), followed by renal cell carcinoma (8%) and uterine leiomyosarcoma (5%). The mean number of pulmonary lesions ablated was 2.4 per patient; the mean size of lesion ablated was 2.2 cm in diameter. Fifteen patients had second-time RFA; 4 patients underwent third- or fourth-time RFA for pulmonary recurrence. There was no post-procedural mortality and the overall morbidity rate was 42%. The most common complication was pneumothorax, which occurred in of 31% of procedures (n=39/127) with 20 (16%) requiring chest tube placement. After a median follow-up of 24 months (range 1 to 70 months), 72% of RFA treated lesions did not progress. The overall median disease-free interval was 13 months, with 1-, 3- and 5- year disease-free survival of 55%, 22% and 7% respectively. The overall median survival was 34 months with 1-, 3- and 5-year- survival of 85%, 49% and 33% respectively. Conclusions: Percutaneous radiofrequency ablation is an emerging therapy with promising results when surgical resection of pulmonary malignancy cannot be performed. No significant financial relationships to disclose.

Pulmonary Lymphangitic Carcinomatosis (PLC): Spectrum of FDG-PET Findings

The lungs are among the most common sites for metastases from a multitude of cancers. The majority of pulmonary metastases appear nodular on radiologic images. Interstitial spread of tumor through pulmonary lymphatics, also known as pulmonary lymphangitic carcinomatosis (PLC), is not uncommon and constitutes approximately 7% of pulmonary metastases. PLC is most often seen with adenocarcinoma of a variety of histologies such as thyroid carcinoma, and melanoma. It is usually noted in late stages of malignancy and therefore is indicative of a poor prognosis. Diagnosis of PLC is usually based on a combination of clinical and radiologic findings. However, the diagnosis is difficult when patients have limited clinical findings or have a history of or the possibility of other interstitial lung diseases. High-resolution computed tomography (HRCT) has been the modality of choice in the radiologic diagnosis of PLC. Imaging features of PLC on HRCT include thickening of interlobular septa, fissures, and bronchovascular bundles. Distribution of PLC may be focal or diffuse, unilateral or bilateral, and symmetric or asymmetric. Although FDG-PET has been extensively used in primary or secondary lung malignancies, its role and appearance in PLC have not been well determined in the literature. In this communication, we describe a spectrum of FDG-PET and CT findings in 5 cases with PLC. Similar to CT, the distribution of PLC can be extensive or limited on the FDG-PET. Diffuse, lobar, or segmental FDG uptake in the lungs is seen in extensive PLC. In limited PLC, a linear or a hazy area of FDG uptake extending from the tumor can be seen. Recognition of various patterns related to PLC on FDG-PET may allow accurate diagnosis of disease and could potentially influence the management of these patients.

Microwave Ablation: Principles and Applications

Microwave ablation is the most recent development in the field of tumor ablation. The technique allows for flexible approaches to treatment, including percutaneous, laparoscopic, and open surgical access. With imaging guidance, the tumor is localized, and a thin (14.5-gauge) microwave antenna is placed directly into the tumor. A microwave generator emits an electromagnetic wave through the exposed, noninsulated portion of the antenna. Electromagnetic microwaves agitate water molecules in the surrounding tissue, producing friction and heat, thus inducing cellular death via coagulation necrosis. The main advantages of microwave technology, when compared with existing thermoablative technologies, include consistently higher intratumoral temperatures, larger tumor ablation volumes, faster ablation times, and an improved convection profile. Microwave ablation has promising potential in the treatment of primary and secondary liver disease, primary and secondary lung malignancies, renal and adrenal tumors, and bone metastases. The technology is still in its infancy, and future developments and clinical implementation will help improve the care of patients with cancer.

Primary and secondary lung malignancies treated with percutaneous radiofrequency ablation: evaluation with follow-up helical CT.

We sought to describe the appearance of primary and secondary lung malignancies treated with radiofrequency ablation on follow-up helical CT and to identify the important CT findings for evaluating therapeutic efficacy and response on follow-up CT. Among the 21 patients in our study population, 17 had lung cancer and four had metastatic nodules. All patients underwent follow-up helical CT immediately after undergoing percutaneous radiofrequency ablation, 1 month later, and then every 3 months. Two reviewers interpreted the CT findings and reached a consensus opinion. Patients were divided into two groups on the basis of the posttreatment contrast-enhanced CT findings-those with a complete ablation and those with a partial ablation. The serial changes in the enhancement pattern, size, peripheral ground-glass opacities, and other findings in the treated area in the two groups were assessed on follow-up CT. In the complete ablation group (n = 9 patients), the ablated lesions were completely without contrast enhancement on follow-up CT, and the mean percentage of decrease in the size of the ablated lesions at 3, 6, 9, 12, and 15 months was 5.7%, 11.4%, 14.3%, 40%, and 40%, respectively, compared with the lesion size on the follow-up CT scans obtained immediately after treatment. In the partial ablation group (n = 12 patients), the ablated lesions had various degrees of enhancement, and the mean percentage of ablated lesion size gradually increased after the 6-month follow-up CT examination. Enveloped ground-glass opacity surrounding tumor was seen in five (23.8%) of 21 lesions on the immediate follow-up CT scans. Of the CT findings of lung malignancy after radiofrequency ablation therapy, the enhancement pattern and the size of the change in the ablated lesion are the most important factors for determining whether a complete ablation has been achieved.

Acute limb ischemia due to malignant arterial embolism from a metastatic germ cell tumor

Arterial tumor embolization is a rare but serious complication of neoplastic disease. The majority of these tumors are associated with primary or secondary lung malignancies, originating from pulmonary vein metastasis or from an atrial mass. Malignant germ cell tumors primarily disseminate to the retroperitoneal lymph nodes and lung, and to the brain and liver later in the course of the disease. A germ cell tumor metastasis embolizing to the iliac-femoral arterial system has not yet been reported. We report a metastatic embolism in a patient with disseminated embryonal cell carcinoma causing acute limb ischemia, managed by surgical embolectomy. The sudden development of limb ischemia in a patient with a germ cell tumor should alert the physician to the possibility of tumor embolism.