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Experience in Stereotactic Radiation Therapy for Lung Cancer
Poster Viewing Abstracts S543
Volume 87 Number 2S Supplement 2013 Poster Viewing Abstract 2890; Table
Day 0
Days 16 vs 0 Days 31 vs 0
3DC free 3DC DIBH VMAT DIBH 3DC DIBH vs free VMAT DIBH vs 3DC free 3DC VMAT 3DC VMAT
MLD
V5
V20
V40
17.3 6.6 Gy 14.7 5.9 Gy 14.0 5.5 Gy 15.6% * 19.3% * 0.6% 1.1% 0.8% 3.3%
51.0 23.6% 45.5 22.4 57.3 25.2% 14.2% * 11.2% * 0.8% 0.1% 1.6% 0.1%
29.0 12.2 24.9 11.0% 24.2 11.0% 14.8% * 17.9%* 0.3% 0.3% 1.1% 0.5%
18.4 6.8% 15.6 6.1% 10.3 4.1% 15.5% * 44.5%* 3.8% 3.5% 0.5% 2.9%
Purpose/Objective(s): Radiation therapy (RT) of lung cancer results in poor survival and high lung toxicity. RT in deep inspiration breath hold (DIBH) has the potential for reducing lung toxicity as lung volume increases. Prior to clinical implementation, evaluation of voluntary DIBH feasibility and reproducibility throughout the treatment course is necessary. Materials/Methods: Ten patients with locally advanced lung cancer entered the study so far. Besides standard imaging for RT planning (4D CT and DIBH CT) 6 patients were also scanned in DIBH at treatment days 16 and 31. Voluntary DIBH were visually guided to a comfortable level with a gating window of 2-3 mm, adjusted to each patient. Respiration was monitored with an optical marker based system. The patients’ capability to increase lung volume and to perform repeated DIBH lasting 20 seconds or more throughout the RT course was considered a measure of feasibility. The 3D conformal (3DC) and Volumetric Modulated Arc Therapy (VMAT) treatment plans were calculated on planning day’s DIBH (DIBHday0) to deliver 66 Gy in 33 fractions. 3DC plan used the same field angles as the clinical free breathing plan. VMAT used 2 full or partial arcs, depending on anatomy. DIBH CT from days 16 and 31 were registered to DIBHday0 with tumor registration. RT plans optimized on DIBHday0 were applied to DIBH from days 16 and 31. Plans were compared on lung parameters V5, V20, V40, mean lung dose (MLD) and target coverage. Results: Lung volume increased in DIBH by 57% (range, 35-87%; p < 0.0001; paired t-test). All patients could perform at least 6 consecutive DIBH lasting over 20 s throughout the treatment course. 3DC plans were planned with 3-5 fields, requiring 3-5 DIBH pr treatment fraction. 8/10 VMAT plans were planned with 2 partial arcs, requiring 4 DIBH pr treatment fraction, 2 full arcs would require 6 DIBH. Lung parameters were significantly reduced in DIBH with both 3DC and VMAT (except V5 in VMAT) with same or better target coverage. Treatment plans applied on DIBH scans from days 16 and 31 showed small non-significant changes of a few % in both lung and target. Data is presented in table as mean SD or mean and marked with * if statistically significant at 0.05 level. Conclusions: DIBH is feasible, well tolerated and gives considerable lung inflation (>50%). Both 3DC and VMAT plans are robust to anatomy changes during a RT course. We are continuously accruing more patients in the protocol in order to strengthen these encouraging early results on feasibility of visually guided voluntary DIBH RT. Author Disclosure: M. Josipovic: None. G.F. Persson: None. K. Ha˚kansson: None. S. Damkjær: None. G. Westman: None. J. Bangsgaard: None. L. Specht: None. M. Aznar: None.
2891 Experience in Stereotactic Radiation Therapy for Lung Cancer L. Larrea, E. LopezMun˜oz, P. Antonini, J. Bea, M. Ban˜os, and M. Garcia; Hospital NISA Virgen del Consuelo, Valencia, Spain Purpose/Objective(s): To review our institution’s last decade experience in patients with medically inoperable lung tumors treated with stereotactic body radiation therapy (SBRT) in terms of local control and survival.
Materials/Methods: Between 2002 and 2012, 112 consecutive patients with 125 lung tumors were treated using SBRT. Those tumors included: lung cancers of any histology (75.2%), metastatic lung nodules (14.4%) or solitary pulmonary nodules suspicious of malignancy with no pathological confirmation (10.4%). Treatment outcomes, toxicity and technique were analyzed retrospectively. SBRT involved: (1) Computed tomography (CT) slow-scan simulation with immobilization devices, (2) contouring the target volume in 3 sets of CTs, (3) superimposing the volumes in the planning system to represent the internal target volume (ITV), (4) dose calculation using heterogeneity correction and assuring very conformal dose distribution and a steep fall-off of the radiation dose outside treatment volume and (5) radiation delivery with multiple static non-coplanar non-opposing beams and arc therapy. The prescribed dose was either 3 fractions of 14-16 Gy each or a single 30-Gy fraction (corresponding to biologically equivalent doses >100). Dose constraints were set for spinal cord and lung volume. Toxicity and radiologic response were assessed in follow-up visits, using conventional criteria (RTOG, EORTC scores and radiologist reviewed reports). Survival rates and cumulative incidences of toxicities were calculated by the KaplanMeier method. Results: Median patient age was 69.3 years (47-86). Mean tumor volume was 6.62 cm3 (0.6-292.7). Acute toxicities were grade 1 or 2 esophagitis, pneumonitis or dermatitis and occurred in 9.6% of all cases. No toxicities grades >3 were identified. The median follow-up was 18 months (3-65). The 2-year survival was 69% for all patients and 75.2% for primary tumors. Local control in the irradiated volume is 95.7%. Conclusions: SBRT is an excellent treatment option for primary or metastatic lung tumors. Our encouraging results in terms of survival, local control and toxicity are in line with those previously reported in recent literature. Author Disclosure: L. Larrea: None. E. LopezMun˜oz: None. P. Antonini: None. J. Bea: None. M. Ban˜os: None. M. Garcia: None.
2892 Salvage Radiation for Mediastinal Relapse After Treatment With Accelerated Hypofractionated Radiation Therapy (AHRT) or Stereotactic Body Radiation Therapy (SBRT) for Stage I/II NSCLC S.C. Lester, J.M. Kilburn, J.T. Lucas, M.T. Munley, A.W. Blackstock, W.T. Kearns, W.H. Hinson, A.A. Miller, W.J. Petty, and J.J. Urbanic; Wake Forest Baptist Health, Winston-Salem, NC Purpose/Objective(s): Regional failures occur in up to 15% of patients (pts) treated with definitive radiation therapy for Stage I/II NSCLC. Limited data exists on the outcome of patients with mediastinal failure after SBRT or AHRT. We present our experience of salvage radiation therapy for mediastinal recurrences after AHRT or SBRT in stage I and II NSCLC. Materials/Methods: All pts treated (rx) with SBRT or AHRT for stage I/II NSCLC were screened for treatment of isolated mediastinal failures (IMF). Pts were included if treated with mediastinal radiation therapy (MRT) and intent was curative. MRT was 3DCRT or IMRT. Prior to 2007, 10 mm PTVexpansions to GTV were applied. No elective nodal coverage was used. A 4D CT derived ITV and 5 mm PTV was used after 2007. Pt failures
Volume 87 Number 2S Supplement 2013 Poster Viewing Abstract 2890; Table
Day 0
Days 16 vs 0 Days 31 vs 0
3DC free 3DC DIBH VMAT DIBH 3DC DIBH vs free VMAT DIBH vs 3DC free 3DC VMAT 3DC VMAT
MLD
V5
V20
V40
17.3 6.6 Gy 14.7 5.9 Gy 14.0 5.5 Gy 15.6% * 19.3% * 0.6% 1.1% 0.8% 3.3%
51.0 23.6% 45.5 22.4 57.3 25.2% 14.2% * 11.2% * 0.8% 0.1% 1.6% 0.1%
29.0 12.2 24.9 11.0% 24.2 11.0% 14.8% * 17.9%* 0.3% 0.3% 1.1% 0.5%
18.4 6.8% 15.6 6.1% 10.3 4.1% 15.5% * 44.5%* 3.8% 3.5% 0.5% 2.9%
Purpose/Objective(s): Radiation therapy (RT) of lung cancer results in poor survival and high lung toxicity. RT in deep inspiration breath hold (DIBH) has the potential for reducing lung toxicity as lung volume increases. Prior to clinical implementation, evaluation of voluntary DIBH feasibility and reproducibility throughout the treatment course is necessary. Materials/Methods: Ten patients with locally advanced lung cancer entered the study so far. Besides standard imaging for RT planning (4D CT and DIBH CT) 6 patients were also scanned in DIBH at treatment days 16 and 31. Voluntary DIBH were visually guided to a comfortable level with a gating window of 2-3 mm, adjusted to each patient. Respiration was monitored with an optical marker based system. The patients’ capability to increase lung volume and to perform repeated DIBH lasting 20 seconds or more throughout the RT course was considered a measure of feasibility. The 3D conformal (3DC) and Volumetric Modulated Arc Therapy (VMAT) treatment plans were calculated on planning day’s DIBH (DIBHday0) to deliver 66 Gy in 33 fractions. 3DC plan used the same field angles as the clinical free breathing plan. VMAT used 2 full or partial arcs, depending on anatomy. DIBH CT from days 16 and 31 were registered to DIBHday0 with tumor registration. RT plans optimized on DIBHday0 were applied to DIBH from days 16 and 31. Plans were compared on lung parameters V5, V20, V40, mean lung dose (MLD) and target coverage. Results: Lung volume increased in DIBH by 57% (range, 35-87%; p < 0.0001; paired t-test). All patients could perform at least 6 consecutive DIBH lasting over 20 s throughout the treatment course. 3DC plans were planned with 3-5 fields, requiring 3-5 DIBH pr treatment fraction. 8/10 VMAT plans were planned with 2 partial arcs, requiring 4 DIBH pr treatment fraction, 2 full arcs would require 6 DIBH. Lung parameters were significantly reduced in DIBH with both 3DC and VMAT (except V5 in VMAT) with same or better target coverage. Treatment plans applied on DIBH scans from days 16 and 31 showed small non-significant changes of a few % in both lung and target. Data is presented in table as mean SD or mean and marked with * if statistically significant at 0.05 level. Conclusions: DIBH is feasible, well tolerated and gives considerable lung inflation (>50%). Both 3DC and VMAT plans are robust to anatomy changes during a RT course. We are continuously accruing more patients in the protocol in order to strengthen these encouraging early results on feasibility of visually guided voluntary DIBH RT. Author Disclosure: M. Josipovic: None. G.F. Persson: None. K. Ha˚kansson: None. S. Damkjær: None. G. Westman: None. J. Bangsgaard: None. L. Specht: None. M. Aznar: None.
2891 Experience in Stereotactic Radiation Therapy for Lung Cancer L. Larrea, E. LopezMun˜oz, P. Antonini, J. Bea, M. Ban˜os, and M. Garcia; Hospital NISA Virgen del Consuelo, Valencia, Spain Purpose/Objective(s): To review our institution’s last decade experience in patients with medically inoperable lung tumors treated with stereotactic body radiation therapy (SBRT) in terms of local control and survival.
Materials/Methods: Between 2002 and 2012, 112 consecutive patients with 125 lung tumors were treated using SBRT. Those tumors included: lung cancers of any histology (75.2%), metastatic lung nodules (14.4%) or solitary pulmonary nodules suspicious of malignancy with no pathological confirmation (10.4%). Treatment outcomes, toxicity and technique were analyzed retrospectively. SBRT involved: (1) Computed tomography (CT) slow-scan simulation with immobilization devices, (2) contouring the target volume in 3 sets of CTs, (3) superimposing the volumes in the planning system to represent the internal target volume (ITV), (4) dose calculation using heterogeneity correction and assuring very conformal dose distribution and a steep fall-off of the radiation dose outside treatment volume and (5) radiation delivery with multiple static non-coplanar non-opposing beams and arc therapy. The prescribed dose was either 3 fractions of 14-16 Gy each or a single 30-Gy fraction (corresponding to biologically equivalent doses >100). Dose constraints were set for spinal cord and lung volume. Toxicity and radiologic response were assessed in follow-up visits, using conventional criteria (RTOG, EORTC scores and radiologist reviewed reports). Survival rates and cumulative incidences of toxicities were calculated by the KaplanMeier method. Results: Median patient age was 69.3 years (47-86). Mean tumor volume was 6.62 cm3 (0.6-292.7). Acute toxicities were grade 1 or 2 esophagitis, pneumonitis or dermatitis and occurred in 9.6% of all cases. No toxicities grades >3 were identified. The median follow-up was 18 months (3-65). The 2-year survival was 69% for all patients and 75.2% for primary tumors. Local control in the irradiated volume is 95.7%. Conclusions: SBRT is an excellent treatment option for primary or metastatic lung tumors. Our encouraging results in terms of survival, local control and toxicity are in line with those previously reported in recent literature. Author Disclosure: L. Larrea: None. E. LopezMun˜oz: None. P. Antonini: None. J. Bea: None. M. Ban˜os: None. M. Garcia: None.
2892 Salvage Radiation for Mediastinal Relapse After Treatment With Accelerated Hypofractionated Radiation Therapy (AHRT) or Stereotactic Body Radiation Therapy (SBRT) for Stage I/II NSCLC S.C. Lester, J.M. Kilburn, J.T. Lucas, M.T. Munley, A.W. Blackstock, W.T. Kearns, W.H. Hinson, A.A. Miller, W.J. Petty, and J.J. Urbanic; Wake Forest Baptist Health, Winston-Salem, NC Purpose/Objective(s): Regional failures occur in up to 15% of patients (pts) treated with definitive radiation therapy for Stage I/II NSCLC. Limited data exists on the outcome of patients with mediastinal failure after SBRT or AHRT. We present our experience of salvage radiation therapy for mediastinal recurrences after AHRT or SBRT in stage I and II NSCLC. Materials/Methods: All pts treated (rx) with SBRT or AHRT for stage I/II NSCLC were screened for treatment of isolated mediastinal failures (IMF). Pts were included if treated with mediastinal radiation therapy (MRT) and intent was curative. MRT was 3DCRT or IMRT. Prior to 2007, 10 mm PTVexpansions to GTV were applied. No elective nodal coverage was used. A 4D CT derived ITV and 5 mm PTV was used after 2007. Pt failures