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Clinical Experience With Respiratory-Gated Stereotactic Body Radiation Therapy (SBRT) for Lung Tumors Using Audio Coaching
S552
International Journal of Radiation Oncology Biology Physics
Conclusions: Higher risk of grade >/Z 2 treatment-related esophagitis was associated with younger age, and higher radiation therapy dose per fraction and should be further evaluated in clinical trials. Author Disclosure: V. Bar Ad: None. M. Witek: None. B. Leiby: None. Y. Xiao: None. Y. Cui: None. Y. Dai: None. J. Cao: None. R. Axelrod: None. B. Campling: None. M. Werner-Wasik: None.
2890
2889 Stereotactic Body Radiation Therapy (SBRT) for Stage I Non-small Cell Lung Cancer (NSCLC): Analysis Based on the New TNM Classification and Difference Due to Histology C. Hashizume,1 Y. Shibamoto,2 Y. Mori,2 T. Tsugawa,1 S. Otsuka,2 A. Hayashi,2 and H. Nakazawa1; 1Nagoya Kyoritsu Hospital-Radiosurgery Center, Nagoya, Japan, 2Department of Radiology and Radiation Oncology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan Purpose/Objective(s): SBRT is becoming a standard treatment for patients with stage I NSCLC who are inoperable or refuse surgery. We started SBRT in July 2006 using the system equipped with micro-multileaf collimators and an accurate patient setup system. In this study, clinical results of SBRT for stage I NSCLC were analyzed based on the new TNM classification (UICC 7th) and with special reference to difference between adenocarcinoma (AD) and squamous cell carcinoma (SCC). Materials/Methods: Enrolled were 105 patients with NSCLC (78 men and 27 women) with a median age of 78 years (range, 55- 89); 57 patients had stage IA (T1a, 13; T1b, 44) cancer and 48 had stage IB (T2a). Ninety-one lesions were histologically confirmed; 51 were AD, 31 were SCC, and 9 were NSCLC. Most cases were inoperable because of chronic lung or other diseases, or high age. The CTV was delineated using CT images taken at 3 phases (expiratory, inspiratory and free breathing). The PTV margin was 5-7 mm. Three coplanar and 4 non-coplanar beams were used. The PTV was covered with 95% or higher isodose lines. Median PTV volume was 43.4 cc (range, 14-108 cc). The standard SBRT dose was 48-50 Gy in 4 fractions over 2 weeks for tumors up to 3 cm in diameter and 52 Gy in 4 fractions in 2 weeks for larger ones. Ten patients were treated with 56-64 Gy in 8 fractions because of proximity to the major risk organs or central location of the tumor. Results: The median follow-up period was 38 months (range, 15-64) for living patients. The 3-year survival rate was 64% for stage IA patients and 41% for stage IB (pZ0.004). The 3-year cause-specific survival rate was 85% and 78%, respectively. The 3-year local control rate was 96% for stage IA and 80% for stage IB (pZ0.008) and the progression-free rate was 74% and 46%, respectively (pZ0.01). No significant differences were noted in any of these rates between T1a and T1b tumors. The 3-year local control rate was 100% for T1a and 95% for T1b. In stage IB patients, the 3year distant metastasis-free rate was significantly lower in AD than SCC patients (45% vs 81%, pZ0.05), while the other rates did not differ significantly. The 3-year survival and local control rates were 55% and 90%, respectively, for patients undergoing 4-fraction SBRT and 47% and 86%, respectively, for those receiving 8-fraction treatment, with no significant difference. Grade 1 and 2 radiation pneumonitis developed in 43% and 15% of the patients, respectively. Conclusions: SBRT is safe and efficient for stage I NSCLC. Stage IB patients had lower survival and local control rates than stage IA patients, but there were no differences between T1a and T1b patients. Stage IB AD patients may require adjuvant chemotherapy in light of the high rate of distant metastasis. Author Disclosure: C. Hashizume: None. Y. Shibamoto: None. Y. Mori: None. T. Tsugawa: None. S. Otsuka: None. A. Hayashi: None. H. Nakazawa: None.
Induction Chemotherapy Plus Concurrent Chemoradiation Therapy (ICCRT) Versus Concurrent Chemoradiation Therapy (CRT) in the Treatment of Unresectable Stage III Non-small Cell Lung Cancer (NSCLC) J. Chang,1 S. Moon,2 K. Cho,2 T. Kim,2 H. Kim,1 and H. Wu1; 1Seoul National University Hospital, Seoul, Korea, Republic of Korea, 2Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Gyeonggi-Do, Korea, Republic of Korea Purpose/Objective(s): The standard of care for unresectable stage III non-small cell lung cancer (NSCLC) is concurrent chemoradiation therapy (CRT). However, some phase II trials are attempting to demonstrate the better survival of induction chemotherapy (ICT) before CRT by applying various chemotherapy regimens. We compared survival outcomes between ICT followed by CRT and CRT alone in the treatment of unresectable stage III NSCLC and evaluated prognostic factors affecting survival. Also, we assessed the relationship of ICT response with survival outcome. Materials/Methods: Medical records of 328 stage III NSCLC patients treated with definitive ICT plus CRT (ICCRT group) or CRT alone (CRT group) from August 2001 to January 2009 were retrospectively reviewed. Of these, 25 patients with suboptimal radiation dose of less than 60 Gy were excluded. There were 148 (49%) and 155 (51%) patients in ICCRT group and CRT group, respectively. The median follow-up time was 24.6 months (range, 1.8w116.7 months). Response of ICT was evaluated before the initiation of treatment and after the end of ICT using computed tomography scan of chest. Results: Median total treatment duration was 125 days in ICCRT and 43 in CRT groups, respectively. Median time of ICT start day to CRT start day was 78 days (range, 28w735 days). Median survival was 24 (ICCRT) and 26 (CRT) months, respectively (p Z 0.302). No statistically significant difference was found in overall survival (OS), progression free survival (PFS) and loco-regional recurrence free survival (LRRFS) between two groups, but there was a trend toward improved distant metastasis free survival (DMFS) with CRT over ICCRT (p Z 0.06). Analysis of ICT response revealed that ICTPR (partial response) group (N Z 84, 57%) had longer median OS than ICTSD (stable disease) + ICTPD (progressive disease) group (N Z 64, 43%) (28 vs 22 months, p Z 0.01). Whereas no significant difference was found in OS between ICTPR and CRT groups (p Z 0.785), ICTSD+PD had worse median OS than CRT group (22 vs 26 months, p Z 0.013). In the multivariate analysis, clinical factors including female, younger age of less than 60 at diagnosis, and adenocarcinoma histology were related to better OS. Conclusions: As a whole, ICCRT did not improve survival outcomes than CRT in unresectable stage III NSCLC patients of our study. Also, ICT response was shown to predict well OS after following CRT. Author Disclosure: J. Chang: None. S. Moon: None. K. Cho: None. T. Kim: None. H. Kim: None. H. Wu: None.
2891 Clinical Experience With Respiratory-Gated Stereotactic Body Radiation Therapy (SBRT) for Lung Tumors Using Audio Coaching F. Baba,1,2 Y. Shibamoto,2 T. Matsui,1 Y. Nonogaki,3 S. Tanaka,3 S. Hasegawa,3 A. Miyakawa,2 S. Takemoto,4 S. Otsuka,2 and H. Iwata5; 1Department of Radiology, Social Insurance Chukyo Hospital, Nagoya, Japan, 2Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, 3 Department of Radiological Technology, Social Insurance Chukyo Hospital, Nagoya, Japan, 4Nambu Tokushukai Hospital, Okinawa, Japan, 5Bureau of Health and Welfare, City of Nagoya, Nagoya, Japan Purpose/Objective(s): Management of respiratory motion is important in SBRT for lung tumors. One approach to the issue is to use
Volume 84 Number 3S Supplement 2012 respiratory gating, but controversy exists regarding the technique. One is regarding the reproducibility of breathing and another is regarding the correlation between the surrogate and tumor motion. Some studies suggested audio instructions could partly solve these problems. The purpose of this study was to evaluate respiratory-gated SBRT using audio coaching. Materials/Methods: CT images for treatment planning were obtained using 4D-CT under audio instruction. Images were reconstructed into 10 phases of the respiratory cycle (0-90%). When the target motion was greater than 1 cm in the craniocaudal (CC) direction, the respiratorygating method was applied. Clinical target volumes around end-expiration were merged individually to form the internal target volume (ITV). The planning target volume (PTV) margin was 5 mm. Patient set-up was verified using cone-beam CT. Tumor motion was checked by fluoroscopy of an on-board imager system before every treatment. When a phase shift between the tumor motion and the duty cycle occurred, the thresholds for gating were modified. Electronic portal images were used to verify the tumor position during SBRT. Between March 2010 and August 2011, 15 patients with 17 lesions of primary or metastatic lung cancer underwent respiratory-gated SBRT using audio coaching. In 10 of them, we compared the variability of the cycle, amplitude and lowest point of respiratory waves between audio coaching and free-breathing conditions. Results: The individually selected percentage of the duty cycle was 30% to 60%. The thresholds for gating were adjusted in 5 patients before treatment. Compared to the entire tumor motion, the amplitude of tumor motion during irradiation was decreased by 0.8-4.1 cm in the CC direction using respiratory gating. The mean ITV and PTV were decreased by 37.6% (range, 16-60%) and 33.8% (range, 1556%), respectively (p<0.0001). The mean reduction in the lung V20 and the mean lung dose was 1.7% (range, 0.5-4.5%) and 1.0 Gy (range, 0.3-2.3 Gy), respectively (p<0.0001). Furthermore, the dose to the stomach could be significantly reduced for 4 lesions at the base of the left lung. During follow-up of 6 months or longer, grade 2 and 3 radiation pneumonitis was observed in 1 patient each with severe emphysema. Compared to free-breathing conditions, the respiratory cycle was improved in 6 cases, and the amplitude and the lowest point of respiratory waves were improved in 1 and 2 cases, respectively. Conclusions: In SBRT for lung tumors, respiratory gating could reduce the dose to the normal tissue. To further control respiration, we are planning to investigate the use of additional devices like visual feedback. Author Disclosure: F. Baba: None. Y. Shibamoto: None. T. Matsui: None. Y. Nonogaki: None. S. Tanaka: None. S. Hasegawa: None. A. Miyakawa: None. S. Takemoto: None. S. Otsuka: None. H. Iwata: None.
2892 Pretreatment FDG PET Tumor Heterogeneity in Non-small Cell Lung Cancer is Associated With Poor Response and Survival Following Chemoradiation Therapy C. Yip,1 D.B. Landau,1,2 S. Ahmad,1 V. Goh,2,3 M. Siddique,2 S. Chicklore,4 A. Roy,5 and G.J. Cook5; 1Department of Oncology, Guys and St Thomas NHS Foundation Trust, London, United Kingdom, 2Division of Imaging Sciences & Biomedical Engineering, Kings College London, London, United Kingdom, 3Department of Radiology, Guys & St Thomas NHS Foundation Trust, London, United Kingdom, 4Nuclear Medicine Department, Guys & St Thomas NHS Foundation Trust, London, United Kingdom, 5Clinical PET Centre, Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, United Kingdom Purpose/Objective(s): There is early evidence in some solid tumors that heterogeneity of tumoral uptake in FDG PET images is associated with poor response to chemoradiation therapy and survival. We have investigated whether a similar relationship exists in non-small cell lung cancer (NSCLC). Materials/Methods: Fifty-three patients (mean age 65.8y, 31 male) with non-small cell lung cancer (21 adenocarcinoma, 24 squamous cell
Poster Viewing Abstracts S553 carcinoma and 8 unspecified), stage 1B (nZ3), 2B (nZ5), 3A (nZ24), 3B (nZ21), treated with 64Gy radiation therapy and concurrent cisplatin/carboplatin and vinorelbine chemotherapy had pre-treatment FDG PET/CT scans performed to the same protocol in the same institution between 2007 and 2009. Patients had response assessed by RECIST criteria at 12 weeks. Overall (OS), progression-free (PFS) and local progression-free survival (LPFS) and/or time to last censoring were recorded from the date of the PET scan. Primary tumor heterogeneity was measured by “coarseness” derived from 3D matrices describing differences between each PET image voxel and its neighbor. Primary tumor SUVmean, SUVmax and SUVpeak parameters were also derived from the PET data. Results: Median OS was 767 days (94-1534), PFS 497 days (84-1346) and LPFS not reached (129-1380). By RECIST there were 2 CR, 34 PR, 9 SD, 2 PD and 6 not recorded. Primary tumor coarseness varied from 0.0006 to 0.096 (mean 0.016). RECIST responders (PR/CR) showed lower coarseness than non-responders (SD/PD) (mean 0.012 vs 0.027, pZ0.003). By Kaplan-Meier analysis, OS, PFS and LPFS were lower in patients with high primary tumor coarseness (median 633 days vs not reached, pZ0.003, 377 vs 774 days, pZ0.002 and 388 vs 616 days, pZ0.016, respectively). None of the SUV parameters predicted RECIST response or showed an association with any of the survival parameters. Conclusions: Increased heterogeneity of baseline FDG PET scan uptake in NSCLC, as measured by the textural parameter, coarseness, is associated with non-response by RECIST and with poorer OS, PFS and LPFS. Measurement of tumor metabolic heterogeneity may be an index that can be used to stratify patients in clinical trials for lung cancer chemoradiation therapy. Author Disclosure: C. Yip: None. D.B. Landau: None. S. Ahmad: None. V. Goh: None. M. Siddique: None. S. Chicklore: None. A. Roy: None. G.J. Cook: None.
2893 Comparisons of Local Control and Survival of Stereotactic Body Radiation Therapy Versus Surgery for Stage I Non-small Cell Lung Cancer: A Meta-Analysis X. Zheng,1 R. Reddy,2 M. Schipper,2 Y. Ren,1 A. Chang,2 J. Lin,2 M. Orringer,2 and F. Kong2; 1Huadong Hospital, Fudan University, Shanghai, China, 2the University of Michigan, Ann Arbor, MI Purpose/Objective(s): This study aims to compare treatment outcomes between stereotactic body radiation therapy (SBRT) and surgery in earlystage non-small-cell lung cancer (NSCLC). Materials/Methods: Eligible studies of SBRT and surgery were retrieved through extensive search of databases of PubMed, Medline, Embase and Cochrane library from 2000 to 2011. Original English publications in stage I NSCLC with adequate sample sizes (30 minimum for SBRT, 100 minimum for surgery) were included. SBRT studies with BED <100 Gy, fraction dose <8 Gy, or using more than 8 fractions were excluded. Data is presented as mean (95% confident interval). Results: Forty-six SBRT studies (3,322 patients) and 34 surgery studies (12,367 patients) published in the same era were eligible. The median age and follow-up duration were 74 years and 27 months for SBRT patients, and 66 years and 42 months for surgery patients, respectively. The overall survival rates at 1-, 3- and 5-year with SBRT were 82.4% (79.8-85.0%), 52.6% (48.4-56.7%) and 37.3% (28.1-46.4%), compared to 91.4% (88.8-94.1%), 77.5% (72.9-82.1%) and 67.5% (61.1-74.0%) with full anatomical resection, and 90.2% (87.3-93.2%), 71.8% (64.3-79.3%) and 54.1% (42.2-66.1%) with limited resection. The cause-specific survival at 3-year was 76.9% (71.6-82.3%) vs. 79.6% (73.0-86.2%) and 5-year 63.7% (53.6-73.9%) vs. 67.1% (56.9-77.4%), for SBRT and surgery. In SBRT group, overall survival was better with increasing operability of patients: in those studies with operability over 60%, the overall survival in SBRT group was not significantly different from that of surgery.
International Journal of Radiation Oncology Biology Physics
Conclusions: Higher risk of grade >/Z 2 treatment-related esophagitis was associated with younger age, and higher radiation therapy dose per fraction and should be further evaluated in clinical trials. Author Disclosure: V. Bar Ad: None. M. Witek: None. B. Leiby: None. Y. Xiao: None. Y. Cui: None. Y. Dai: None. J. Cao: None. R. Axelrod: None. B. Campling: None. M. Werner-Wasik: None.
2890
2889 Stereotactic Body Radiation Therapy (SBRT) for Stage I Non-small Cell Lung Cancer (NSCLC): Analysis Based on the New TNM Classification and Difference Due to Histology C. Hashizume,1 Y. Shibamoto,2 Y. Mori,2 T. Tsugawa,1 S. Otsuka,2 A. Hayashi,2 and H. Nakazawa1; 1Nagoya Kyoritsu Hospital-Radiosurgery Center, Nagoya, Japan, 2Department of Radiology and Radiation Oncology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan Purpose/Objective(s): SBRT is becoming a standard treatment for patients with stage I NSCLC who are inoperable or refuse surgery. We started SBRT in July 2006 using the system equipped with micro-multileaf collimators and an accurate patient setup system. In this study, clinical results of SBRT for stage I NSCLC were analyzed based on the new TNM classification (UICC 7th) and with special reference to difference between adenocarcinoma (AD) and squamous cell carcinoma (SCC). Materials/Methods: Enrolled were 105 patients with NSCLC (78 men and 27 women) with a median age of 78 years (range, 55- 89); 57 patients had stage IA (T1a, 13; T1b, 44) cancer and 48 had stage IB (T2a). Ninety-one lesions were histologically confirmed; 51 were AD, 31 were SCC, and 9 were NSCLC. Most cases were inoperable because of chronic lung or other diseases, or high age. The CTV was delineated using CT images taken at 3 phases (expiratory, inspiratory and free breathing). The PTV margin was 5-7 mm. Three coplanar and 4 non-coplanar beams were used. The PTV was covered with 95% or higher isodose lines. Median PTV volume was 43.4 cc (range, 14-108 cc). The standard SBRT dose was 48-50 Gy in 4 fractions over 2 weeks for tumors up to 3 cm in diameter and 52 Gy in 4 fractions in 2 weeks for larger ones. Ten patients were treated with 56-64 Gy in 8 fractions because of proximity to the major risk organs or central location of the tumor. Results: The median follow-up period was 38 months (range, 15-64) for living patients. The 3-year survival rate was 64% for stage IA patients and 41% for stage IB (pZ0.004). The 3-year cause-specific survival rate was 85% and 78%, respectively. The 3-year local control rate was 96% for stage IA and 80% for stage IB (pZ0.008) and the progression-free rate was 74% and 46%, respectively (pZ0.01). No significant differences were noted in any of these rates between T1a and T1b tumors. The 3-year local control rate was 100% for T1a and 95% for T1b. In stage IB patients, the 3year distant metastasis-free rate was significantly lower in AD than SCC patients (45% vs 81%, pZ0.05), while the other rates did not differ significantly. The 3-year survival and local control rates were 55% and 90%, respectively, for patients undergoing 4-fraction SBRT and 47% and 86%, respectively, for those receiving 8-fraction treatment, with no significant difference. Grade 1 and 2 radiation pneumonitis developed in 43% and 15% of the patients, respectively. Conclusions: SBRT is safe and efficient for stage I NSCLC. Stage IB patients had lower survival and local control rates than stage IA patients, but there were no differences between T1a and T1b patients. Stage IB AD patients may require adjuvant chemotherapy in light of the high rate of distant metastasis. Author Disclosure: C. Hashizume: None. Y. Shibamoto: None. Y. Mori: None. T. Tsugawa: None. S. Otsuka: None. A. Hayashi: None. H. Nakazawa: None.
Induction Chemotherapy Plus Concurrent Chemoradiation Therapy (ICCRT) Versus Concurrent Chemoradiation Therapy (CRT) in the Treatment of Unresectable Stage III Non-small Cell Lung Cancer (NSCLC) J. Chang,1 S. Moon,2 K. Cho,2 T. Kim,2 H. Kim,1 and H. Wu1; 1Seoul National University Hospital, Seoul, Korea, Republic of Korea, 2Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Gyeonggi-Do, Korea, Republic of Korea Purpose/Objective(s): The standard of care for unresectable stage III non-small cell lung cancer (NSCLC) is concurrent chemoradiation therapy (CRT). However, some phase II trials are attempting to demonstrate the better survival of induction chemotherapy (ICT) before CRT by applying various chemotherapy regimens. We compared survival outcomes between ICT followed by CRT and CRT alone in the treatment of unresectable stage III NSCLC and evaluated prognostic factors affecting survival. Also, we assessed the relationship of ICT response with survival outcome. Materials/Methods: Medical records of 328 stage III NSCLC patients treated with definitive ICT plus CRT (ICCRT group) or CRT alone (CRT group) from August 2001 to January 2009 were retrospectively reviewed. Of these, 25 patients with suboptimal radiation dose of less than 60 Gy were excluded. There were 148 (49%) and 155 (51%) patients in ICCRT group and CRT group, respectively. The median follow-up time was 24.6 months (range, 1.8w116.7 months). Response of ICT was evaluated before the initiation of treatment and after the end of ICT using computed tomography scan of chest. Results: Median total treatment duration was 125 days in ICCRT and 43 in CRT groups, respectively. Median time of ICT start day to CRT start day was 78 days (range, 28w735 days). Median survival was 24 (ICCRT) and 26 (CRT) months, respectively (p Z 0.302). No statistically significant difference was found in overall survival (OS), progression free survival (PFS) and loco-regional recurrence free survival (LRRFS) between two groups, but there was a trend toward improved distant metastasis free survival (DMFS) with CRT over ICCRT (p Z 0.06). Analysis of ICT response revealed that ICTPR (partial response) group (N Z 84, 57%) had longer median OS than ICTSD (stable disease) + ICTPD (progressive disease) group (N Z 64, 43%) (28 vs 22 months, p Z 0.01). Whereas no significant difference was found in OS between ICTPR and CRT groups (p Z 0.785), ICTSD+PD had worse median OS than CRT group (22 vs 26 months, p Z 0.013). In the multivariate analysis, clinical factors including female, younger age of less than 60 at diagnosis, and adenocarcinoma histology were related to better OS. Conclusions: As a whole, ICCRT did not improve survival outcomes than CRT in unresectable stage III NSCLC patients of our study. Also, ICT response was shown to predict well OS after following CRT. Author Disclosure: J. Chang: None. S. Moon: None. K. Cho: None. T. Kim: None. H. Kim: None. H. Wu: None.
2891 Clinical Experience With Respiratory-Gated Stereotactic Body Radiation Therapy (SBRT) for Lung Tumors Using Audio Coaching F. Baba,1,2 Y. Shibamoto,2 T. Matsui,1 Y. Nonogaki,3 S. Tanaka,3 S. Hasegawa,3 A. Miyakawa,2 S. Takemoto,4 S. Otsuka,2 and H. Iwata5; 1Department of Radiology, Social Insurance Chukyo Hospital, Nagoya, Japan, 2Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, 3 Department of Radiological Technology, Social Insurance Chukyo Hospital, Nagoya, Japan, 4Nambu Tokushukai Hospital, Okinawa, Japan, 5Bureau of Health and Welfare, City of Nagoya, Nagoya, Japan Purpose/Objective(s): Management of respiratory motion is important in SBRT for lung tumors. One approach to the issue is to use
Volume 84 Number 3S Supplement 2012 respiratory gating, but controversy exists regarding the technique. One is regarding the reproducibility of breathing and another is regarding the correlation between the surrogate and tumor motion. Some studies suggested audio instructions could partly solve these problems. The purpose of this study was to evaluate respiratory-gated SBRT using audio coaching. Materials/Methods: CT images for treatment planning were obtained using 4D-CT under audio instruction. Images were reconstructed into 10 phases of the respiratory cycle (0-90%). When the target motion was greater than 1 cm in the craniocaudal (CC) direction, the respiratorygating method was applied. Clinical target volumes around end-expiration were merged individually to form the internal target volume (ITV). The planning target volume (PTV) margin was 5 mm. Patient set-up was verified using cone-beam CT. Tumor motion was checked by fluoroscopy of an on-board imager system before every treatment. When a phase shift between the tumor motion and the duty cycle occurred, the thresholds for gating were modified. Electronic portal images were used to verify the tumor position during SBRT. Between March 2010 and August 2011, 15 patients with 17 lesions of primary or metastatic lung cancer underwent respiratory-gated SBRT using audio coaching. In 10 of them, we compared the variability of the cycle, amplitude and lowest point of respiratory waves between audio coaching and free-breathing conditions. Results: The individually selected percentage of the duty cycle was 30% to 60%. The thresholds for gating were adjusted in 5 patients before treatment. Compared to the entire tumor motion, the amplitude of tumor motion during irradiation was decreased by 0.8-4.1 cm in the CC direction using respiratory gating. The mean ITV and PTV were decreased by 37.6% (range, 16-60%) and 33.8% (range, 1556%), respectively (p<0.0001). The mean reduction in the lung V20 and the mean lung dose was 1.7% (range, 0.5-4.5%) and 1.0 Gy (range, 0.3-2.3 Gy), respectively (p<0.0001). Furthermore, the dose to the stomach could be significantly reduced for 4 lesions at the base of the left lung. During follow-up of 6 months or longer, grade 2 and 3 radiation pneumonitis was observed in 1 patient each with severe emphysema. Compared to free-breathing conditions, the respiratory cycle was improved in 6 cases, and the amplitude and the lowest point of respiratory waves were improved in 1 and 2 cases, respectively. Conclusions: In SBRT for lung tumors, respiratory gating could reduce the dose to the normal tissue. To further control respiration, we are planning to investigate the use of additional devices like visual feedback. Author Disclosure: F. Baba: None. Y. Shibamoto: None. T. Matsui: None. Y. Nonogaki: None. S. Tanaka: None. S. Hasegawa: None. A. Miyakawa: None. S. Takemoto: None. S. Otsuka: None. H. Iwata: None.
2892 Pretreatment FDG PET Tumor Heterogeneity in Non-small Cell Lung Cancer is Associated With Poor Response and Survival Following Chemoradiation Therapy C. Yip,1 D.B. Landau,1,2 S. Ahmad,1 V. Goh,2,3 M. Siddique,2 S. Chicklore,4 A. Roy,5 and G.J. Cook5; 1Department of Oncology, Guys and St Thomas NHS Foundation Trust, London, United Kingdom, 2Division of Imaging Sciences & Biomedical Engineering, Kings College London, London, United Kingdom, 3Department of Radiology, Guys & St Thomas NHS Foundation Trust, London, United Kingdom, 4Nuclear Medicine Department, Guys & St Thomas NHS Foundation Trust, London, United Kingdom, 5Clinical PET Centre, Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, United Kingdom Purpose/Objective(s): There is early evidence in some solid tumors that heterogeneity of tumoral uptake in FDG PET images is associated with poor response to chemoradiation therapy and survival. We have investigated whether a similar relationship exists in non-small cell lung cancer (NSCLC). Materials/Methods: Fifty-three patients (mean age 65.8y, 31 male) with non-small cell lung cancer (21 adenocarcinoma, 24 squamous cell
Poster Viewing Abstracts S553 carcinoma and 8 unspecified), stage 1B (nZ3), 2B (nZ5), 3A (nZ24), 3B (nZ21), treated with 64Gy radiation therapy and concurrent cisplatin/carboplatin and vinorelbine chemotherapy had pre-treatment FDG PET/CT scans performed to the same protocol in the same institution between 2007 and 2009. Patients had response assessed by RECIST criteria at 12 weeks. Overall (OS), progression-free (PFS) and local progression-free survival (LPFS) and/or time to last censoring were recorded from the date of the PET scan. Primary tumor heterogeneity was measured by “coarseness” derived from 3D matrices describing differences between each PET image voxel and its neighbor. Primary tumor SUVmean, SUVmax and SUVpeak parameters were also derived from the PET data. Results: Median OS was 767 days (94-1534), PFS 497 days (84-1346) and LPFS not reached (129-1380). By RECIST there were 2 CR, 34 PR, 9 SD, 2 PD and 6 not recorded. Primary tumor coarseness varied from 0.0006 to 0.096 (mean 0.016). RECIST responders (PR/CR) showed lower coarseness than non-responders (SD/PD) (mean 0.012 vs 0.027, pZ0.003). By Kaplan-Meier analysis, OS, PFS and LPFS were lower in patients with high primary tumor coarseness (median 633 days vs not reached, pZ0.003, 377 vs 774 days, pZ0.002 and 388 vs 616 days, pZ0.016, respectively). None of the SUV parameters predicted RECIST response or showed an association with any of the survival parameters. Conclusions: Increased heterogeneity of baseline FDG PET scan uptake in NSCLC, as measured by the textural parameter, coarseness, is associated with non-response by RECIST and with poorer OS, PFS and LPFS. Measurement of tumor metabolic heterogeneity may be an index that can be used to stratify patients in clinical trials for lung cancer chemoradiation therapy. Author Disclosure: C. Yip: None. D.B. Landau: None. S. Ahmad: None. V. Goh: None. M. Siddique: None. S. Chicklore: None. A. Roy: None. G.J. Cook: None.
2893 Comparisons of Local Control and Survival of Stereotactic Body Radiation Therapy Versus Surgery for Stage I Non-small Cell Lung Cancer: A Meta-Analysis X. Zheng,1 R. Reddy,2 M. Schipper,2 Y. Ren,1 A. Chang,2 J. Lin,2 M. Orringer,2 and F. Kong2; 1Huadong Hospital, Fudan University, Shanghai, China, 2the University of Michigan, Ann Arbor, MI Purpose/Objective(s): This study aims to compare treatment outcomes between stereotactic body radiation therapy (SBRT) and surgery in earlystage non-small-cell lung cancer (NSCLC). Materials/Methods: Eligible studies of SBRT and surgery were retrieved through extensive search of databases of PubMed, Medline, Embase and Cochrane library from 2000 to 2011. Original English publications in stage I NSCLC with adequate sample sizes (30 minimum for SBRT, 100 minimum for surgery) were included. SBRT studies with BED <100 Gy, fraction dose <8 Gy, or using more than 8 fractions were excluded. Data is presented as mean (95% confident interval). Results: Forty-six SBRT studies (3,322 patients) and 34 surgery studies (12,367 patients) published in the same era were eligible. The median age and follow-up duration were 74 years and 27 months for SBRT patients, and 66 years and 42 months for surgery patients, respectively. The overall survival rates at 1-, 3- and 5-year with SBRT were 82.4% (79.8-85.0%), 52.6% (48.4-56.7%) and 37.3% (28.1-46.4%), compared to 91.4% (88.8-94.1%), 77.5% (72.9-82.1%) and 67.5% (61.1-74.0%) with full anatomical resection, and 90.2% (87.3-93.2%), 71.8% (64.3-79.3%) and 54.1% (42.2-66.1%) with limited resection. The cause-specific survival at 3-year was 76.9% (71.6-82.3%) vs. 79.6% (73.0-86.2%) and 5-year 63.7% (53.6-73.9%) vs. 67.1% (56.9-77.4%), for SBRT and surgery. In SBRT group, overall survival was better with increasing operability of patients: in those studies with operability over 60%, the overall survival in SBRT group was not significantly different from that of surgery.