Stereotactic Body Radiation Therapy (SBRT) represents the newest plateau in the art and science of radiation oncology. Previously unimaginable radiation doses are administered precisely and non-invasively in an aggressive, decisive action to eradicate a discrete focus of cancer.
SBRT has evolved as a result of enormous technological advances in image-guided therapy. As the name implies, the technology involves the use of external fiducial markers referenced in 3-D space to internal targets, allowing stereotactic guidance of treatment to targets within the body. Previously applied monikers included the term “Stereotactic Radioablation,” which conveyed the sense that the high-dose treatment is intended to ablate, or completely eradicate, targeted tumors. “Extracranial Radiosurgery” is another popular term, appealing insofar as it reflects the debt SBRT owes to cranial radiosurgery, through which the concept of stereotactic localization has been refined. However, as discussed in the book, “radiosurgery” generally implies a single fraction course of treatment, whereas SBRT is quite commonly administered in a hypofractioned regimen of 3-5 fractions.
Equally important for the development of SBRT have been the accomplishments in diagnostic imaging and systemic therapy during the last decade. High-quality CT, MRI, and PET scans can provide very accurate information about the exact locations of measurable deposits of tumor cells within a cancer patient's body. Newer chemotherapy combinations and novel growth factor-targeted drugs have achieved significant improvements in progression-free survival for many solid tumors. The complementary role of SBRT, then, is to provide directly cytotoxic treatment focally to the clinically evident disease sites that are unlikely to be cleared with systemic agents alone. Competing with SBRT in this regard are the numerous invasive methodologies for accomplishing this same goal, namely surgical resection and temperature-based therapies (radiofrequency ablation and cryosurgery). The advantage of SBRT in many cases is the greatly reduced toxicity profile, lack of invasiveness, and capacity to deliver the treatment entirely on an outpatient basis.
This book is partly constructed as an educational tool for all oncologists to promote understanding of the power and elegance of SBRT as a new and important weapon in the cancer-fighting arsenal. Modern multidisciplinary management strategies mandate input from radiation, medical, and surgical oncologists—and we all need to keep sight of the expanding frontiers of each other's primary modalities.
At the same time that we acknowledge that SBRT is made possible by technological progress in medical physics, we must concede that SBRT will only be implemented safely and effectively with an appreciation of the underlying basic and clinical radiobiology. In their learned contribution to this book, Dr. Fowler and colleagues explain that to attain a high probability of actually killing off a tumor with radiation, it requires a biologically very potent dose—much more than is generally given with conventionally fractionated treatment.
Here is the catch: if you give the tumor a large dose of radiation, then some adjacent normal tissue will get a large dose as well. Fortunately, with careful attention to technique, it is frequently possible to steer the radiation toward the tumor from enough different directions that only a very small rim of normal tissue is affected noticeably. Just how much radiation can really be given with SBRT remains to be seen, and the radiation oncology community needs to continue careful clinical-biologicalphysics-inclusive translational research to establish where the reasonable safe limits really are. In seeking great success, we risk great failure, so we are compelled to work together.
The book is also, then, intended to be a primer for radiation oncologists, physicists, radiobiologists, dosimetrists, therapists, and other invaluable members of the team who wish to become comfortable with emerging techniques that raise radiotherapy to bold new heights.
SBRT has evolved as a result of enormous technological advances in image-guided therapy. As the name implies, the technology involves the use of external fiducial markers referenced in 3-D space to internal targets, allowing stereotactic guidance of treatment to targets within the body. Previously applied monikers included the term “Stereotactic Radioablation,” which conveyed the sense that the high-dose treatment is intended to ablate, or completely eradicate, targeted tumors. “Extracranial Radiosurgery” is another popular term, appealing insofar as it reflects the debt SBRT owes to cranial radiosurgery, through which the concept of stereotactic localization has been refined. However, as discussed in the book, “radiosurgery” generally implies a single fraction course of treatment, whereas SBRT is quite commonly administered in a hypofractioned regimen of 3-5 fractions.
Equally important for the development of SBRT have been the accomplishments in diagnostic imaging and systemic therapy during the last decade. High-quality CT, MRI, and PET scans can provide very accurate information about the exact locations of measurable deposits of tumor cells within a cancer patient's body. Newer chemotherapy combinations and novel growth factor-targeted drugs have achieved significant improvements in progression-free survival for many solid tumors. The complementary role of SBRT, then, is to provide directly cytotoxic treatment focally to the clinically evident disease sites that are unlikely to be cleared with systemic agents alone. Competing with SBRT in this regard are the numerous invasive methodologies for accomplishing this same goal, namely surgical resection and temperature-based therapies (radiofrequency ablation and cryosurgery). The advantage of SBRT in many cases is the greatly reduced toxicity profile, lack of invasiveness, and capacity to deliver the treatment entirely on an outpatient basis.
This book is partly constructed as an educational tool for all oncologists to promote understanding of the power and elegance of SBRT as a new and important weapon in the cancer-fighting arsenal. Modern multidisciplinary management strategies mandate input from radiation, medical, and surgical oncologists—and we all need to keep sight of the expanding frontiers of each other's primary modalities.
At the same time that we acknowledge that SBRT is made possible by technological progress in medical physics, we must concede that SBRT will only be implemented safely and effectively with an appreciation of the underlying basic and clinical radiobiology. In their learned contribution to this book, Dr. Fowler and colleagues explain that to attain a high probability of actually killing off a tumor with radiation, it requires a biologically very potent dose—much more than is generally given with conventionally fractionated treatment.
Here is the catch: if you give the tumor a large dose of radiation, then some adjacent normal tissue will get a large dose as well. Fortunately, with careful attention to technique, it is frequently possible to steer the radiation toward the tumor from enough different directions that only a very small rim of normal tissue is affected noticeably. Just how much radiation can really be given with SBRT remains to be seen, and the radiation oncology community needs to continue careful clinical-biologicalphysics-inclusive translational research to establish where the reasonable safe limits really are. In seeking great success, we risk great failure, so we are compelled to work together.
The book is also, then, intended to be a primer for radiation oncologists, physicists, radiobiologists, dosimetrists, therapists, and other invaluable members of the team who wish to become comfortable with emerging techniques that raise radiotherapy to bold new heights.
Brian Kavanagh, Robert Timmerman
Prologue: The Clinical Transition from Cranial to Extracranial Stereotactic Radiation Therapy
I. The Radiobiology of Extracranial Stereotactic Radiation Therapy (SBRT)
- Tumor Dose-Response Relationships in SBRT: Do traditional Models Apply?
- The intracellular signaling response to high dose radiation
- Normal tissue Dose-constraints in Lung SBRT
- Normal tissue Dose-constraints in Liver SBRT
- Radiation-induced cytokine production: mechanisms and potential clinical implications
- Special topics: the dose rate effect, margin selection, and resistant subpopulations
II. The Physics and Dosimetry of SBRT
- Immobilization, Localization, and Repositioning Methods in SBRT
- Treatment Planning
- Quality Assurance in SBRT
III. Initiating an SBRT Program
- Equipment and physical layout
- Commissioning and accreditation
- Personnel Training
IV. Clinical Applications of SBRT approx.
- SBRT for lung tumors
- Case Studies in Lung SBRT
- SBRT for Liver Tumors
- Case Studies in Liver SBRT
- SBRT for renal cell carcinoma
- SBRT in retroperitoneal and pelvic tumors
- Case Study in Pelvic SBRT
- Spinal Radiosurgery
- Case studies in spine Radiosurgery
Epilogue: Group Protocols and Future Directions in SBRT
Hardcover: 160 pages
Publisher: Lippincott Williams & Wilkins; 1 edition (September 21, 2004)
Language: English
ISBN-10: 0781754208 / ISBN-13: 978-0781754200
List Price: $163.95