Trial of the Cyberknife in Treating Recurrent Gynecologic Patients Shows High Response Rate, but also High Disease Progression at Nine Month Follow-Up
The study of the use of stereotactive radiosurgery using the CyberKnife Robotic Radiosurgery System (Accuray, Inc., Sunnyvale, Ca.) in treating recurrent gynecologic cancers found that over two-thirds of patients experienced some benefit from the treatment, according to a presentation at this year’s annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago.
Half the patients experienced a complete response following treatment with the Cyberknife, but upon follow-up, over half the patients had progressive disease in regions not targeted with the robotic radiation, and 36% of the patients in the study subsequently died of progressive disease, according to abstract 5102, “Phase II trial of robotic stereotactic radiosurgery (SBRT) in patients with recurrent gynecologic malignancies.”
The prospective phase II study was the first formal study to assess the device in that disease state that was conducted at Case Comprehensive Cancer Center, in Cleveland, Ohio. Case Western is the institution with the largest experience using the Cyberknife to treat recurrent gynecologic cancers, having treated over 100 women with the technique, according to Robert DeBernardo, MD, assistant professor of gynecologic malignancies, co-author of the study.
Prognosis for recurrent gynecologic cancer varies with the site of the tumor, such as vagina, cervix, uterus, fallopian tubes or ovaries, DeBernardo said. “When it comes back, for some patients we have good options , but for others we don’t. For example, most ovarian cancers come back at some point, but we have good options with chemotherapy for those patients. However, the textbooks tell us that 80% of patients have advanced disease, in which case about 70% eventually will die from it. With some therapies, patients live 66 months on average, but for those with stage three or four disease, five year survival ranges only from 20 to 40%,” he explained.
In the study, DeBernardo and colleagues followed 50 patients with recurrent and measurable gynecologic malignancy, who were treated with the Cyberknife. The cohort, which was accrued between July of 2009 and September of 2011, included 25 patients with recurrent ovarian cancer, 14 with endometrial disease, nine with cervical, and two with vulvar cancer. Patients received radiation in three daily doses of 800 gray apiece, guided in part by PET molecular imaging. While at a median of nine months follow-up, 25 patients had enjoyed a complete response, 26 patients, or 52%, had progressive disease at other sites, and 18 patients had died from recurrent cancer, the abstract said. However, 33 patients, or 66%, enjoyed a progression-free interval of at least six months.
“We were not expecting to see five year survival for the cohort, because many of these patients had already received between four and six lines of therapy, and a couple of them had also received surgery with the Da Vinci surgical robot,” explained DeBernardo, who himself also uses the Da Vinci surgical robot for some patients.
Use of the Cyberknife is especially helpful in treating patients whose cancer recurs in the abdomen or pelvis, according to DeBernardo. “In the pelvis, recurrences are especially difficult to get to with traditional radiation, without impacting the bladder or the bowel. For those women who receive intravenous therapy initially, the cancer will recur in the abdomen first,” he explained.
The abstract noted that while researchers accomplished excellent control of targeted lesions, high progressive disease rates elsewhere necessitate trials combining radiation with chemotherapy.
“In a new trial, we are combining this technique with gemcitabine and carboplatin administered intravenously,” said DeBernardo, noting that two of three patients sought for the Phase I trial have been enrolled.
The researchers hope to have data to submit at the meeting of the Society of Gynecologic Oncologists, March 9 in Los Angeles, he added.
The study of the use of stereotactive radiosurgery using the CyberKnife Robotic Radiosurgery System (Accuray, Inc., Sunnyvale, Ca.) in treating recurrent gynecologic cancers found that over two-thirds of patients experienced some benefit from the treatment, according to a presentation at this year’s annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago.
Half the patients experienced a complete response following treatment with the Cyberknife, but upon follow-up, over half the patients had progressive disease in regions not targeted with the robotic radiation, and 36% of the patients in the study subsequently died of progressive disease, according to abstract 5102, “Phase II trial of robotic stereotactic radiosurgery (SBRT) in patients with recurrent gynecologic malignancies.”
The prospective phase II study was the first formal study to assess the device in that disease state that was conducted at Case Comprehensive Cancer Center, in Cleveland, Ohio. Case Western is the institution with the largest experience using the Cyberknife to treat recurrent gynecologic cancers, having treated over 100 women with the technique, according to Robert DeBernardo, MD, assistant professor of gynecologic malignancies, co-author of the study.
Prognosis for recurrent gynecologic cancer varies with the site of the tumor, such as vagina, cervix, uterus, fallopian tubes or ovaries, DeBernardo said. “When it comes back, for some patients we have good options , but for others we don’t. For example, most ovarian cancers come back at some point, but we have good options with chemotherapy for those patients. However, the textbooks tell us that 80% of patients have advanced disease, in which case about 70% eventually will die from it. With some therapies, patients live 66 months on average, but for those with stage three or four disease, five year survival ranges only from 20 to 40%,” he explained.
In the study, DeBernardo and colleagues followed 50 patients with recurrent and measurable gynecologic malignancy, who were treated with the Cyberknife. The cohort, which was accrued between July of 2009 and September of 2011, included 25 patients with recurrent ovarian cancer, 14 with endometrial disease, nine with cervical, and two with vulvar cancer. Patients received radiation in three daily doses of 800 gray apiece, guided in part by PET molecular imaging. While at a median of nine months follow-up, 25 patients had enjoyed a complete response, 26 patients, or 52%, had progressive disease at other sites, and 18 patients had died from recurrent cancer, the abstract said. However, 33 patients, or 66%, enjoyed a progression-free interval of at least six months.
“We were not expecting to see five year survival for the cohort, because many of these patients had already received between four and six lines of therapy, and a couple of them had also received surgery with the Da Vinci surgical robot,” explained DeBernardo, who himself also uses the Da Vinci surgical robot for some patients.
Use of the Cyberknife is especially helpful in treating patients whose cancer recurs in the abdomen or pelvis, according to DeBernardo. “In the pelvis, recurrences are especially difficult to get to with traditional radiation, without impacting the bladder or the bowel. For those women who receive intravenous therapy initially, the cancer will recur in the abdomen first,” he explained.
The abstract noted that while researchers accomplished excellent control of targeted lesions, high progressive disease rates elsewhere necessitate trials combining radiation with chemotherapy.
“In a new trial, we are combining this technique with gemcitabine and carboplatin administered intravenously,” said DeBernardo, noting that two of three patients sought for the Phase I trial have been enrolled.
The researchers hope to have data to submit at the meeting of the Society of Gynecologic Oncologists, March 9 in Los Angeles, he added.
posted by John J. Otrompke | 1:36 PM
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