Role of Transarterial Radioembolisation in Metastatic Lung Lesions

Primary objectives ·       To assess the  feasibility of transarterial radioembolization in treating metastatic lung tumors ·       Assessment of clinical efficacy of transarterial radioembolization in metastatic lung lesionsRadioembolisation Procedure

CTBA will be acquired in standard institutional split bolus protocol prior to procedure and images will be reviewed to detect the location, number, diameter (maximum, in mm), and origin of culprit artery. Target lesion diameter and its distance from the hilum and pleura will also be recorded.  Tumor volume will be calculated by drawing 3-d VOI around the obtained images. Three volumes of interest (VOIs) will be determined to perform the dosimetry: Tumoral volume (TV), which is the volume of the targeted pulmonary lesion, and non-tumoral volume (NTV), discretizing this one into ipsilateral lung non-tumoral volume (iNTV), which is the healthy tissue within the ipsilateral lung, and contralateral lung non-tumoral volume (cNTV), which is the healthy tissue volume in contralateral lung.  Acquired images will be processed for the estimated     dose received in target lesions and healthy tissues. For radioembolization procedure patent catheter in the predominant tumor feeding bronchial artery will be established. The treatment dose will be determined using above mentioned scan findings. Once the activity is defined, after catheterization of the bronchial artery, the therapeutic radiopharmaceutical will be administered. Radioembolisation agent (Y-90 microspheres or Re-188 lipiodol) will be slowly infused to the target artery, avoiding backflow. After treatment, the patient will undergo post-therapy imaging in nuclear medicine department to ensure the proper distribution of the radiopharmaceutical and post-therapy dosimetry. After the procedure, any adverse effects (cough, rash, vomiting, fever, fatigue, etc.) shall be documented. Laboratory test results (complete blood count and complete metabolic panel, coagulation profile) will be obtained 2 weeks after the procedure and repeated at 6 weeks, 3 months and 6 months follow up. Pulmonary function tests will be done at 6 weeks, 3 months and 6 months post-therapy. For toxicity in lab parameters, latest Common Terminology Criteria for Adverse Events (CTCAE) will be preferred to wherever applicable. If any toxicity occurs such as, hematological toxicities will be initially treated with growth factors and transfusions and further if not responding with growth factors and transfusions, it shall be treated with stem cell rescue. Pulmonary toxicity will be treated according to standard established guidelines for treatment of respiratory distress or restrictive airway disease. Response to treatment will be evaluated at 6 weeks and 3 months after the procedure, using the modified Response Evaluation Criteria in Solid Tumors (mRECIST version 1.1) and Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) criteria. CECT parameters like tumor diameter, maximum cross-sectional diameters, tumor volume, tumor enhancement and PET parameter the peak standardized uptake value corrected for lean body mass (SULpeak peak SUL in a spherical 1-cm3 VOI) will be chosen to assess the response.