From the Guidelines
Stereotactic Body Radiotherapy (SBRT) is a highly precise radiation therapy technique that delivers high doses of radiation to small, well-defined tumors in just a few treatment sessions, with local control rates of 90% at 5 years for peripherally located stage I NSCLC 1.
Definition and Purpose
SBRT uses advanced imaging and positioning systems to target tumors with millimeter accuracy, allowing for the delivery of ablative radiation doses while minimizing exposure to surrounding healthy tissues. This treatment is typically administered in 1-5 sessions (fractions), compared to conventional radiotherapy which may require 20-40 sessions.
Indications and Usage
SBRT is most commonly used for early-stage lung cancer, liver tumors, pancreatic cancer, prostate cancer, and oligometastatic disease (limited metastatic tumors) 1. The precision of SBRT allows for higher biological effective doses to be delivered to the tumor, potentially improving local control rates compared to conventional radiotherapy.
Side Effects and Considerations
Patients undergoing SBRT may experience side effects specific to the treated area, such as fatigue, skin irritation, or inflammation of nearby organs, though these are often less severe than with conventional radiotherapy due to the reduced exposure of healthy tissues 1.
Equipment and Treatment Planning
SBRT requires specialized equipment including linear accelerators with image guidance capabilities, and treatment planning involves a multidisciplinary team of radiation oncologists, medical physicists, and radiation therapists to ensure accurate delivery.
- Key considerations for SBRT include:
- Tumor size and location
- Patient's overall health and medical history
- Availability of specialized equipment and expertise
- Potential side effects and quality of life implications
- According to recent guidelines, SBRT is recommended for patients who are medically inoperable or who refuse to have surgery after thoracic surgery evaluation 1.
From the Research
Definition and Purpose of Stereotactic Body Radiotherapy (SBRT)
- SBRT is a method of external beam radiotherapy that accurately delivers a high dose of irradiation in one or few treatment fractions 2.
- It has emerged as a new technology in radiotherapy delivery, allowing for potentially curative treatment in many patients previously felt not to be candidates for radical surgical resection of stage I non-small-cell lung cancer (NSCLC) 3.
Clinical Impact and Patient Perspectives
- SBRT has demonstrated very high local control rates, and more recent data have suggested overall survival may approach that of surgery in operable patients 3.
- The balance of toxicity and effect on patient-reported quality of life need to be considered with respect to oncologic outcomes 3.
- SBRT is a standard treatment option for patients with early-stage non-small cell lung cancer (ES-NSCLC) who are unfit for surgery or refuse to undergo an operation 2.
Treatment Outcomes and Toxicities
- Local control rates of up to 98% at 3 years and overall survival ranging from 43% to 95% at 3 years have been reported in patients with central and peripheral early stage NSCLC 4.
- SBRT is generally well tolerated with 10%-30% grade 3-4 toxicities and a few treatment-related deaths 4.
- Distant failure is common, and chemotherapy may be considered for select patients 4.
Indications and Controversies
- SBRT may be reasonably offered to elderly patients and those with severe COPD, but may need to be approached with caution in patients with interstitial lung disease or central/ultracentral lesions 3, 2.
- The optimal follow-up practice for patients treated with SBRT, including the frequency of imaging and the use of PET-CT, remains unclear 2.
- SBRT for tumours larger than 5 cm is poorly studied, but may be an option for peripherally located lung and abdominal tumours 5.