IsoRay (NYSE:ISR) today released data from a study of its Cesium-131 brachytherapy for treating patients with large brain metastases, touting a 100% freedom from local progression.

Results from the study were published in the International Journal of Radiation Oncology, Biology, Physics, the Richland, Wash.-based company said.

In the study, researchers assessed the impact of low-dose rate Cesium-131 brachytherapy on local control and radionecrosis in 42 patients treated for a total of 46 large brain metastases. Patients in the trial underwent surgical resection with intra-operative palcement of standard Cesium-131 seeds as permanent volume implants in the resection cavity, the company said.

Results from the trial indicated a 100% freedom from local progression rate, meaning brain metastases did not re-grow, and a 0% rate of radionecrosis. Study authors concluded that the Cesium-131 brachytherapy was “safe and effective adjuvant therapy for large brain metastases requiring neurosurgical intervention,” the company said.

“Evidence of Cesium-131’s efficacy in treating brain cancer continues to increase as supported by this important study. The work of Drs. Wernicke and Schwartz is truly pioneering and provides hope that we can continue to improve the available treatment for those afflicted with brain metastases. Treatment of brain metastases is a large unmet need and we’re gratified that our Cesium-131 product has promise to be effective for the many in need,” chief scientific officer Bill Cavanagh said in a press release.

Previous claims of 100% results from IsoRay have been met with serious criticism. In March, Isoray won approval for a $3.5 million settlement related to a class action suit brought against it last June in which shareholders claimed the company had made misleading statements about the 1st trial of its Cesium-131.

In the suit, investors accused the company of making false or misleading statements about the 1st major peer-reviewed study of its brachytherapy seeds in its own press release.

The company’s press release came out May 20, 2016, 1 day after the study was published in the journal Brachytherapy. IsoRay’s release claimed a 100% survival rate at 5 years in high-risk patients and a 96% success rate in local tumor control. ISR shares surged on the news, more than doubling to $3.12 apiece by the market’s close May 20.

But the next day TheStreet.com published an article criticizing IsoRay’s claims, challenging the company’s interpretation of the data and accusing IsoRay of publishing false claims to inflate its stock value. The Brachytherapy report found that other treatments showed statistically equivalent survival and local tumor control rates. IsoRay shares fell 35.3% to a $2.02-per-share close May 21

The company initially announced the settlement last Sept., but stipulated that the settlement was “subject to a number of conditions” including final court approval, and said that it would communicate to potential class members before a decision is made.