Podcast Beta
Questions and Answers
What type of technique involves delivering dosage to only one port/field?
Single Field Dosage
Which technique involves delivering dosage between 2 or more portals of entry?
Crossfire Technique
What is the purpose of the Quadratic (Box Technique)?
Deliver dosage using 4 fields
When is the Perpendicular Field technique used?
Signup and view all the answers
What is the primary purpose of the Wedge Field technique?
Signup and view all the answers
When is the Mantle Field technique typically employed?
Signup and view all the answers
Why is radiation given preoperatively before surgery for tumor treatment?
Signup and view all the answers
What is the purpose of using a simulator in radiotherapy?
Signup and view all the answers
What is the significance of SAD (Source-Axis Distance) in radiotherapy?
Signup and view all the answers
What does SSD (Source-Skin Distance) refer to in radiotherapy?
Signup and view all the answers
What is the purpose of STD (Source-Tumor Distance) in radiation treatment?
Signup and view all the answers
Describe the process of treatment planning in radiotherapy.
Signup and view all the answers
Study Notes
Verification and Dosimetry in Radiation Oncology
- Dosimetry checking and record keeping are essential in radiation oncology
- The target volume is the tumor site or area to be treated
Factors to Consider Before Treatment
- Patient's overall physical and emotional condition
- Type and stage of tumor
- Histology type of tumor
- Extent and anatomic position of tumor
- Time-dose fractionation
- Radiation oncology unit capabilities
- Goal of treatment: cure, pre-operative, or post-operative palliation
Procedures of Isodose Planning
- Single Field Dosage: delivers dosage to only one port/field, used for skin cancer treatment
- Opposing Ports: delivers dosage to field-1 and field-2
- Crossfire Technique: uses 2 or more portals of entry
- Quadratic (Box Technique): delivers dosage to 4 fields
- Multiple Fields: expands opposing ports, delivering dosage to 3 or more fields
- Perpendicular Field: delivers dosage perpendicularly
- Rotational Field: the source rotates around the patient, used for esophageal cancer treatment
- Tangential Field: uses tangential projection for breast or superficial tumor treatment
- Wedge Field: alters the primary beam to accomplish treatment goal, uses a wedge-shaped Pb block
Other Techniques
- Mantle Field: used for upper tumor treatment, targeting major lymph node groups above the diaphragm
- Inverted-Y (Hockey Stick): used for lower tumor treatment, targeting para-aortic inguinal lymph nodes with a central pelvic block
- Chemotherapy: used for systemic treatment of micro-metastases in patients with extensive or chemo-sensitive tumors
- Pre-Operative Technique: radiotherapy followed by surgery or chemotherapy
- Post-Operative Technique: surgery followed by radiotherapy treatment
Simulator in Radiation Therapy
- Localizes target volume and normal tissue
- Localizes boundary of noninvolved organs
- Visualizes the plan of treatment fields
- Uses X-ray fluoroscopy, CT or MRI images, and ultrasonography
Distances Used in Radiotherapy
- SAD (Source-Axis Distance): distance from treatment source to target tumor
- SSD (Source-Skin Distance): distance from source to skin surface
- STD (Source-Tumor Distance): distance from source to target tumor
Treatment Planning
- Requires decisions on volume selection and location of treatment
- Decides on dose to be delivered
- Determines how the volume is treated: teletherapy or brachytherapy
- Computes dosage
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the verification of set-up and portal imaging, dosimetry checking, target volume considerations, and factors impacting treatment decisions in radiation therapy planning.
