External-beam partial breast irradiation delivers cost-effective treatment
External-beam partial breast irradiation (EB-PBI) is the most cost-effective method for treating postmenopausal women with early-stage breast cancer, compared with whole-breast radiotherapy (WBRT) and brachytherapy partial breast irradiation (brachy-PBI), according to a study in the June 1 issue of the International Journal of Radiation Oncology*Biology*Physics.
PBI is a newer form of radiation therapy for breast cancer where only part of the breast is treated twice a day for four to five days. According to the authors, radiation oncologists have been studying different methods to deliver the radiation to the tumor. EB-PBI uses high-energy external x-rays to deliver radiation to the breast after a lumpectomy and brachy-PBI delivers radiation through either implanted needles or a small sphere placed into the post-lumpectomy cavity in the breast.
David Sher, MD, from the Harvard Radiation Oncology Program in Boston, and colleagues developed a Markov model to describe health states in the 15 years after radiotherapy for early-stage breast cancer. EB-PBI and brachy-PBI (MammoSite) were considered and assumed to be equally effective, but carried different costs. The authors adapted utilities, recurrence risks and costs from the literature; the baseline utility for no disease after radiotherapy was set at 0.92. Also, they discounted costs (in 2004 U.S. dollars) and quality-adjusted life-years at 3 percent per year.
The incremental cost-effectiveness ratio for WBRT compared with EB-PBI was $630,000/quality-adjusted life-year; WBRT strongly dominated MS-PBI, according to the investigators. One-way sensitivity analysis found that results were sensitive to PBI hazard ratio, recurrence pattern, baseline recurrence risk and no evidence of disease PBI utility values.
Sher and colleagues also showed that probabilistic sensitivity of EB-PBI was the most cost-effective technique over a wide range of assumptions and societal willingness-to-pay values.
Based on their findings, the researchers concluded that EB-PBI was the most cost-effective strategy for postmenopausal women with early stage breast cancer. "Unless the quality of life after MS-PBI proves to be superior, it is unlikely to be cost-effective," they wrote.
PBI is a newer form of radiation therapy for breast cancer where only part of the breast is treated twice a day for four to five days. According to the authors, radiation oncologists have been studying different methods to deliver the radiation to the tumor. EB-PBI uses high-energy external x-rays to deliver radiation to the breast after a lumpectomy and brachy-PBI delivers radiation through either implanted needles or a small sphere placed into the post-lumpectomy cavity in the breast.
David Sher, MD, from the Harvard Radiation Oncology Program in Boston, and colleagues developed a Markov model to describe health states in the 15 years after radiotherapy for early-stage breast cancer. EB-PBI and brachy-PBI (MammoSite) were considered and assumed to be equally effective, but carried different costs. The authors adapted utilities, recurrence risks and costs from the literature; the baseline utility for no disease after radiotherapy was set at 0.92. Also, they discounted costs (in 2004 U.S. dollars) and quality-adjusted life-years at 3 percent per year.
The incremental cost-effectiveness ratio for WBRT compared with EB-PBI was $630,000/quality-adjusted life-year; WBRT strongly dominated MS-PBI, according to the investigators. One-way sensitivity analysis found that results were sensitive to PBI hazard ratio, recurrence pattern, baseline recurrence risk and no evidence of disease PBI utility values.
Sher and colleagues also showed that probabilistic sensitivity of EB-PBI was the most cost-effective technique over a wide range of assumptions and societal willingness-to-pay values.
Based on their findings, the researchers concluded that EB-PBI was the most cost-effective strategy for postmenopausal women with early stage breast cancer. "Unless the quality of life after MS-PBI proves to be superior, it is unlikely to be cost-effective," they wrote.