Image-Guided Navigation for High Dose Rate Temporary Interstitial Brachytherapy in the Palliative Management of Previously Treated Tumors of the Spine and Pelvis

Inclusion Criteria: * Patients must have histologic proof of a malignancy suitable for radiation therapy. * Patients must have received prior external beam radiation therapy to the region proposed for HDR brachytherapy treatment; evaluation of doses previously delivered to spinal cord/cauda equine, pelvis, and other critical structures (bowel, kidneys, rectum) will be taken into consideration. * If repeat irradiation would exceed any normal tissue constraint set by MSKCC Radiation Oncology Department dose constraint criteria, the patient will potentially be eligible. * If the total prior radiation dose to the cord or pelvis exceeds 100 Gy BED equivalent, the patient will be potentially eligible, where a total of 100 BED Gy equivalent is determined by the biological equivalent dose (BED) calculation; BED = nd(1 + d/α/β), where n = number of fractions and d = dose per fraction; α/β is the constant for spinal cord late effect and equals 2. \[Rades 2005, Nieder 2005, Sahgal 2012\] * KPS ≥ 60 * Age ≥ 18 years old Exclusion Criteria: * Patients who may receive therapeutically effective doses via an external beam approach to the lesion of interest as specified by MSKCC Radiation Oncology Department dose constraint criteria. * Patients with kyphoplasty cement or hardware that would preclude effective catheter placement. * Patients with paraspinal extension of disease with visceral involvement. * Abnormal complete blood count. Any of the following: * Platelet count \< 75,000/ml * H…