SBRT or Stereotaxic Body Radiation Therapy - Targeted XRT
Posted: Thu Oct 14, 2010 7:40 am
Hi there,
I wanted to add a topic of SBRT which might be a newer therapy that could be helpful for some of you. Many people know that gamma knife can be successful for brain ASPS mets, but SBRT is the equivalent for other delicate areas such as certain tumors in the lung or bone.
The lung is very sensitive to radiation, so it cannot take regular XRT because it causes a pneumonitis, but like gamma knife, what SBRT does is uses subtoxic, but multiple streams of radiation - that all summates precisely in a tumor that has been mapped out in 3 dimensional coordinates.
This may be helpful in ASPS when a tumor is inoperable because it is located too close to blood vessels in the mediastinum or inoperable because it would require essentially a lobectomy or pneumonectomy. We just spoke yesterday to Noah Federman who said he had several patients (sarcoma / ASPS) who thus far have done very well with SBRT. It requires only 3-5 days of treatment - Noah said the tumor doesn't necessary go away, but it stops growing. Some may grow after months, years - then they can be treated with some other therapy like ablation.
I will paste in a an abstract below and other refs. This may be another helpful weapon for some in the arsenal against ASPS.
SBRT in Inoperable Lung Cancer: http://www.medscape.com/viewarticle/718760
SBRT at UCLA: http://radonc.ucla.edu/body.cfm?id=61
Acta Oncol. 2006;45(7):808-17.
Stereotactic Body Radiation Therapy (SBRT) for lung metastases.
Okunieff P, Petersen AL, Philip A, Milano MT, Katz AW, Boros L, Schell MC.
Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA. paul_okunieff@urmc.rochester.edu
Abstract
The curative treatment of oligometastases with radiotherapy remains an area of active investigation. We hypothesise that treating oligometastases with SBRT can prolong life and potentially cure patients, while in patients with multiple lung metastases SBRT can improve quality of life. Fifty patients with lung metastases were treated on this study. Individuals with five or fewer total lesions were treated with curative intent. Individuals with > five metastases were treated palliatively. Most patients (62%) received 5 Gy/fraction for a total of 50 Gy. The number of targets treated per patient ranged from one to five (mean 2.6). Tumor sizes ranged from 0.3-7.7 cm in maximal diameter (median 2.1 cm). Mean follow-up was 18.7 months. Local control of treated lesions was obtained in 42 of 49 evaluable patients (83%). Of the 125 total lesions treated, eight progressed after treatment (94% crude local control). The median overall survival time from time of treatment completion of the curatively treated patients was 23.4 months. The progression-free survival of the same group of patients was 25% and 16% at 12 and 24 months, respectively. Grade 1 toxicity occurred in 35% of all the patients, 6.1% had grade 2 toxicity, and 2% had grade 3 toxicity. Excellent local tumor control rates with low toxicity are seen with SBRT. Median survival time and progression-free survival both appear better than that achieved with standard care alone. Long-term progression-free survival can be seen in a subset of patients when all tumors are targeted.
I wanted to add a topic of SBRT which might be a newer therapy that could be helpful for some of you. Many people know that gamma knife can be successful for brain ASPS mets, but SBRT is the equivalent for other delicate areas such as certain tumors in the lung or bone.
The lung is very sensitive to radiation, so it cannot take regular XRT because it causes a pneumonitis, but like gamma knife, what SBRT does is uses subtoxic, but multiple streams of radiation - that all summates precisely in a tumor that has been mapped out in 3 dimensional coordinates.
This may be helpful in ASPS when a tumor is inoperable because it is located too close to blood vessels in the mediastinum or inoperable because it would require essentially a lobectomy or pneumonectomy. We just spoke yesterday to Noah Federman who said he had several patients (sarcoma / ASPS) who thus far have done very well with SBRT. It requires only 3-5 days of treatment - Noah said the tumor doesn't necessary go away, but it stops growing. Some may grow after months, years - then they can be treated with some other therapy like ablation.
I will paste in a an abstract below and other refs. This may be another helpful weapon for some in the arsenal against ASPS.
SBRT in Inoperable Lung Cancer: http://www.medscape.com/viewarticle/718760
SBRT at UCLA: http://radonc.ucla.edu/body.cfm?id=61
Acta Oncol. 2006;45(7):808-17.
Stereotactic Body Radiation Therapy (SBRT) for lung metastases.
Okunieff P, Petersen AL, Philip A, Milano MT, Katz AW, Boros L, Schell MC.
Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA. paul_okunieff@urmc.rochester.edu
Abstract
The curative treatment of oligometastases with radiotherapy remains an area of active investigation. We hypothesise that treating oligometastases with SBRT can prolong life and potentially cure patients, while in patients with multiple lung metastases SBRT can improve quality of life. Fifty patients with lung metastases were treated on this study. Individuals with five or fewer total lesions were treated with curative intent. Individuals with > five metastases were treated palliatively. Most patients (62%) received 5 Gy/fraction for a total of 50 Gy. The number of targets treated per patient ranged from one to five (mean 2.6). Tumor sizes ranged from 0.3-7.7 cm in maximal diameter (median 2.1 cm). Mean follow-up was 18.7 months. Local control of treated lesions was obtained in 42 of 49 evaluable patients (83%). Of the 125 total lesions treated, eight progressed after treatment (94% crude local control). The median overall survival time from time of treatment completion of the curatively treated patients was 23.4 months. The progression-free survival of the same group of patients was 25% and 16% at 12 and 24 months, respectively. Grade 1 toxicity occurred in 35% of all the patients, 6.1% had grade 2 toxicity, and 2% had grade 3 toxicity. Excellent local tumor control rates with low toxicity are seen with SBRT. Median survival time and progression-free survival both appear better than that achieved with standard care alone. Long-term progression-free survival can be seen in a subset of patients when all tumors are targeted.