Helical tomotherapy: image guidance and adaptive dose guidance

Area of Science:

• Radiation Oncology
• Medical Physics
• Radiotherapy Technology

Background:

• Helical tomotherapy is an advanced intensity-modulated radiation therapy (IMRT) system.
• Accurate patient setup is crucial for effective IMRT, especially for complex treatment plans.
• Image guidance systems are essential for verifying patient positioning before radiation delivery.

Purpose of the Study:

• To highlight the role of pretreatment megavoltage (MV) CT imaging in helical tomotherapy.
• To explain how MV CT facilitates interfraction setup error correction.
• To demonstrate the capability of MV CT in verifying target position and motion envelopes.

Main Methods:

• Utilizing daily pretreatment megavoltage (MV) CT imaging for patient setup verification.
• Employing helical tomotherapy, a volumetric image-guided IMRT delivery system.
• Leveraging the slow imaging nature of helical MV CT to encode target motion data.

Main Results:

• Daily MV CT imaging enables accurate correction of interfraction setup errors.
• Image guidance with MV CT allows direct target position verification in the treatment position.
• Helical MV CT data can encode target motion, allowing for pretreatment verification of motion envelopes.

Conclusions:

• Pretreatment MV CT imaging is vital for accurate patient setup in helical tomotherapy.
• Image guidance using MV CT enhances the precision of IMRT delivery.
• Helical MV CT imaging supports the verification of target motion, improving treatment accuracy.