Four dimensional radiotherapy
Radiotherapy of lung cancer is affected by respiration-related motion and volume changes that frequently require larger safety margins than in other tumor locations. Four dimensional (4D) radiotherapy planning has been introduced as a routine procedure at VCU Massey Cancer Center both for early- and advanced-stage lung tumors. With this innovative imaging method we are able to measure tumor motion and integrate this information to optimally target the tumor while improving normal tissue sparing.
Several options of respiration management are available:
- Audiovisual biofeedback is used to guide the patients' breathing.
- Respiration gating and active breathing control are used to reduce tumor motion while the patient undergoes radiotherapy.
- These methods further increase our ability to focus the treatment dose on the tumor and reduce dose to healthy tissue.
During therapy, several image guidance techniques are used to reliably localize the tumor position. Small markers are implanted in the tumor (available only on approved clinical trials) and innovative cone beam CT imaging is used for 3D (and 4D on study protocols) verification of the correct tumor position during treatment.
For therapy, conventional and intensity-modulated 3D radiotherapy and high-precision stereotactic radiotherapy techniques are available.