Clinical Outcomes of Large Brain Metastases Treated With Neurosurgical Resection and Intraoperative Cesium-131 Brachytherapy: Results of a Prospective Trial

Feasibility of dose escalation using intraoperative radiotherapy following resection of large brain metastases compared to post-operative stereotactic radiosurgery

“…A number of alternative techniques to low energy X-ray based IORT have been described for the treatment of brain metastases including permeant low dose rate brachytherapy with 125 I and 131 Cs as well as temporary implants with balloon based delivery of aqueous 125 I [6–8, 11, 12]. Low energy X-ray based IORT has advantages of avoiding concerns of seed migration, no need for special handling precautions of radioactive sources, and eliminates the complexity of seed placement thereby reducing anesthesia time and potential re-operation for seed removal in temporary brachytherapy implants.…”

“…IORT has advantages of eliminating challenges in target definition, steep conformal dose delivery that may afford dose-escalation relative to SRS, and increased patient convenience by integrating resection and radiotherapy into 1 procedure. A variety of techniques have been used for IORT in brain metastases including low-energy photons and permanent low dose rate brachytherapy with 131 Cs and 125 I [6–8, 11, 12]. However, dose selection for low energy photon based IORT in brain tumors remains largely empiric with doses ranging from 10 to 30 Gy in 1 fraction to varying prescription depths of 0–5 mm [6–10].…”

Placement of 131 Cs permanent brachytherapy seeds in a large combined cavity of two resected brain metastases in one setting: case report and technical note

“…This could be associated with high rates of radiation necrosis of up to 26%, when treated with 125 I [11]. Our recently published study revealed that 131 Cs rendered excellent local control with no incidences of radiation necrosis, as evidenced clinically and radiographically [13,14]. We have previously published a report on cavity shrinkage, where we determined that during the first month, when approximately 88% of 131 Cs dosage is delivered, there was an insignificant decrease in volume within the 131 Cs treatment group (median 22.0%, p = 0.063) [20].…”

“…However, a number of recent studies have shown that that local control is significantly reduced for resected tumors with large (> 3 cm) preoperative diameters [14]. These studies suggest that a greater preoperative tumor diameter is a significant predictor of local failure [14]. In this report, we are presenting on a patient with two adjacent metastases, which were resected through one craniotomy.…”

“…In a recently published prospective study of 24 individuals treated with maximally safe neurological resection and intraoperative 131 Cs for the treatment of newly diagnosed brain metastases, there was a 100% rate of freedom from progression (FFP), with 0% incidence of radiation necrosis, determined clinically and radiographically (median follow-up of 19.3 months) [13]. However, a number of recent studies have shown that that local control is significantly reduced for resected tumors with large (> 3 cm) preoperative diameters [14]. These studies suggest that a greater preoperative tumor diameter is a significant predictor of local failure [14].…”