Author of

• 17783

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  P2.05 - Poster Session with Presenters Present (ID 463)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/06/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 17834

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    P2.05-051 - Safety of Lung Stereotactic Body Radiotherapy (SBRT): A Single Institution Prospective Study Based on RTOG 0915 Protocol Constraints (ID 4124)

    14:30 - 14:30  |  Author(s): V. Vanoni
    • Abstract

    Background:
    To evaluate toxicity of RTOG 0915 protocol’s constraints in lung SBRT for patients treated with 60Gy in 5 fractions.
    
    Methods:
    Between 2010 and 2015, 77 pts were treated with SBRT for single or multiple lung lesions, 43 pts. (55.8%) for primary tumor and 34 pts. (44.2%) for metastatic lesion. A total of 80 lesions were treated. Four dimensional CT images were acquired; maximum intensity CT reconstruction was used for ITV delineation and average CT reconstruction for OAR contouring and dosimetric calculation.We prescribed 57Gy to 95% of PTV volume and OAR constraints are reported in table 1. Figure 1 Dose calculation was performed in 70% of the cases with collapsed cone convolution algorithm and 7 fields 3D technique and the remaining 30% with Monte Carlo dose calculation and intensity modulated fields (dynamic MLC and VMAT tecniques). Treatments were delivered in 28% of the cases on Elekta-Precise accelerator with electronic portal films on-line setup verifications and the remaining 72% on Elekta-Agility accelerator with cone beam CT. We evaluated pre-treatment respiratory function and we treated only pts. with %FEV1 > 40%. We reported toxicity following CTCAE v3.0 score.
    
    
    
    Results:
    All the dose/constraints were respected except for the chest wall dose that was higher than 30 Gy in 8 pts. (10.3%). Toxicity was evaluated in all the patients except one that was lost in follow-up. We found only lung or chest wall toxicity: 11 pts. (14.2%) with a G2 dyspnea, one patient with a G3 dyspnea; 8 pts. with a G2 chest wall pain and 1 with a symptomatic rib fracture . We find more lung toxicity in patients with primary tumor because of more chronic lung disease prior to the treatment.
    
    Conclusion:
    The use of these SBRT constraints is safe in both metastatic and primary lung lesions, with a particular attention on pre-treatment respiratory function.