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Prophylactic Radiotherapy to Prevent Procedure Tract Metastasis in Malignant Pleural Mesothelioma
I. J. Radiation Oncology d Biology d Physics
S508
2679
Volume 78, Number 3, Supplement, 2010
Preliminary Results in the Treatment of Recurrent Non-small Cell Lung Cancer (NSCLC) with Stereotactic Body Radiation Therapy (SBRT): Does Total Dose and Tumor Volume Impact Local Control?
J. E. Costello1,2, E. P. Finnerty2, R. L. Deming1, D. K. Strom2, K. J. Bernstein1, N. J. Bellville1, C. M. Burgin1, R. P. Jacobsen1, D. R. Puri1 1 Mercy Medical Center, Department of Radiation Oncology, Des Moines, IA, 2Des Moines University, College of Osteopathic Medicine, Des Moines, IA
Purpose/Objective(s): Recently published results of RTOG 0236 highlight outstanding local control (LC) rates when SBRT is used for inoperable early-stage NSCLC. However, data concerning efficacy and safety of SBRT for recurrent NSCLC remains limited. The main purpose of this retrospective study was to identify treatment and tumor characteristics that might predict for better LC when SBRT is employed for solitary pulmonary recurrences. We also report on short- and intermediate-term toxicities in this cohort of patients, many of whom received prior thoracic radiotherapy (TRT). Materials/Methods: From 4/05-7/09, 28 patients with recurrent NSCLC were treated with SBRT using a robotic system (CyberKnife, Accuray, Sunnyvale, CA) with fiducial-based respiratory tracking. All recurrences were biopsy-proven and/or PET-avid (SUV$4.5) solitary lesions. Median SBRT dose was 48Gy (range: 24-60 Gy in 3-5 fractions), with treatment margins (GTV-to-PTV) of 0-5 mm. Median GTV was 21cc (range: 2-83cc). Seventy-five percent of patients received prior TRT for their primary NSCLC. Median time between TRT and SBRT was 29 months (range: 7-113 months). Toxicities were scored by the RTOG criteria. Results: With a median follow-up of 12.6 months (range: 4-34 months), 1- and 2-year actuarial LC was 66% and 44%, respectively. Overall survival was 56% at 1 year and 40% at 2 years. Both total dose and GTV were found to be predictive of LC. Nine local failures occurred at a dose of #48Gy, compared to one local failure at 60Gy (p = 0.009). An inverse correlation (p = 0.018) was found between GTV and LC, as 80% of local failures occurred with a GTV of $25cc. Grade #2 pulmonary fibrosis and cough were the two most common adverse effects, occurring in 57% and 35% of patients, respectively. Grade #2 pneumonitis occurred in 28% of patients, with no statistically significant relationship between incidence of pneumonitis and prior TRT (p = 0.33). One Grade 3 (fibrosis) and no Grade 4 toxicities were reported. Pneumothorax occurred in 25% of patients who underwent fiducial placement. Conclusions: SBRT appears to be a reasonable and well-tolerated approach in the local management of recurrent NSCLC, especially when higher total doses are used. Our current practice is to deliver 60Gy in 3 fractions to low-volume thoracic recurrences whenever possible. Recurrent lesions .25cc may benefit from higher total doses or a non-SBRT treatment approach. Our preliminary results will need to be validated by prospective studies of SBRT in the recurrent setting so that more concrete practice guidelines can be established for the stereotactic treatment of recurrent NSCLC. Longer follow-up is required to determine the full extent of late effects in this mostly previously irradiated cohort. Author Disclosure: J.E. Costello, None; E.P. Finnerty, None; R.L. Deming, None; D.K. Strom, None; K.J. Bernstein, None; N.J. Bellville, None; C.M. Burgin, None; R.P. Jacobsen, None; D.R. Puri, None.
2680
Prophylactic Radiotherapy to Prevent Procedure Tract Metastasis in Malignant Pleural Mesothelioma
M. Froment1, E´ Fre´chette2, A. Dagnault1 1 De´partement de Radio-oncologie, L’Hoˆtel-Dieu de Que´bec, Centre Hospitalier Universitaire de Que´bec (CHUQ), Quebec, QC, Canada, 2De´partement de Chirurgie Thoracique, Institut Universitaire de Cardiologie Et De Pneumologie de l’Universite´ Laval, Quebec, QC, Canada
Purpose/Objective(s): Prophylactic radiotherapy to intervention sites (PIT) in malignant pleural mesothelioma has been used for several years. In the literature, the effectiveness of this technique is controversial. Thus, the aim of this study was to assess the effectiveness of PIT to prevent tumor seeding in a large cohort of patients with malignant pleural mesothelioma in chemotherapy era. Materials/Methods: We performed a retrospective review of the case files of a cohort of 299 patients undergoing or not PIT between June 1985 and March 2009. From this cohort, we excluded 128 patients for lack of follow-up (\1 month), histopathologically unproved or non-mesothelioma cancer at the biopsy. Moreover, we excluded patients who had undergone gross tumor resection. Results: Forty-eight patients (28%) received PIT and 123 patients (72%) did not receive this treatment. The median follow-up was 9.3 months and 73% of patients were following until dead. Chemotherapy was given in 32.7% of patients. Most patients have received a Cisplatin-pemetrexed regimen. Patients were irradiated with a median delay of 27 days after their chest instrumentation, most often thoracoscopy (82.6%). The median dose of PIT was 21Gy in 3 fractions with electrons or 6MV photons. The median field size was 63.45cm2. During follow-up, 6 patients (12.5%) in the PIT group had a tumor invasion of the skin compared to 40 patients (32.5%) in the group without PIT (p = 0.008). For all of the 6 patients in the PIT group, these tract metastases were in the radiotherapy field. Among these, 4 patients (66.7%) had pain secondary to their lesion. Three had additional radiotherapy treatment and 66.7% patients had a good response. Thirty patients (75%) in the group without PIT had pain secondary to their tract metastasis. Thirteen patients in this group had radiotherapy treatment and 64.3% had a good response. The median delay between the procedure and the tumor skin invasion was longer in the PIT group (5.03 vs. 3.83 months respectively). Moreover, the local progression free survival (LPFS) at the intervention site was better in the PIT group (p = 0.004). At 1 year, LPFS for the intervention sites was 86.0% with PIT and 63.4% without PIT. Furthermore, the cancer-specific survival (CSS) and the overall survival (OS) were better in the group with PIT. At 1 year, CSS was 66.9% with PIT and 45.5% without PIT (p = 0.035) and the OS was 66.8% and 40.4% respectively (p = 0.037). Conclusions: This study suggests that PIT in mesothelioma reduces the incidence of procedure tract metastasis, and should be offered to patients because the majority of these newly developed lesions are symptomatic. Moreover, PIT seems to improve the OS and the CSS. Finally, a radiotherapy treatment should be attempted in patients with symptomatic tract metastasis. Author Disclosure: M. Froment, None; E´. Fre´chette, None; A. Dagnault, None.
S508
2679
Volume 78, Number 3, Supplement, 2010
Preliminary Results in the Treatment of Recurrent Non-small Cell Lung Cancer (NSCLC) with Stereotactic Body Radiation Therapy (SBRT): Does Total Dose and Tumor Volume Impact Local Control?
J. E. Costello1,2, E. P. Finnerty2, R. L. Deming1, D. K. Strom2, K. J. Bernstein1, N. J. Bellville1, C. M. Burgin1, R. P. Jacobsen1, D. R. Puri1 1 Mercy Medical Center, Department of Radiation Oncology, Des Moines, IA, 2Des Moines University, College of Osteopathic Medicine, Des Moines, IA
Purpose/Objective(s): Recently published results of RTOG 0236 highlight outstanding local control (LC) rates when SBRT is used for inoperable early-stage NSCLC. However, data concerning efficacy and safety of SBRT for recurrent NSCLC remains limited. The main purpose of this retrospective study was to identify treatment and tumor characteristics that might predict for better LC when SBRT is employed for solitary pulmonary recurrences. We also report on short- and intermediate-term toxicities in this cohort of patients, many of whom received prior thoracic radiotherapy (TRT). Materials/Methods: From 4/05-7/09, 28 patients with recurrent NSCLC were treated with SBRT using a robotic system (CyberKnife, Accuray, Sunnyvale, CA) with fiducial-based respiratory tracking. All recurrences were biopsy-proven and/or PET-avid (SUV$4.5) solitary lesions. Median SBRT dose was 48Gy (range: 24-60 Gy in 3-5 fractions), with treatment margins (GTV-to-PTV) of 0-5 mm. Median GTV was 21cc (range: 2-83cc). Seventy-five percent of patients received prior TRT for their primary NSCLC. Median time between TRT and SBRT was 29 months (range: 7-113 months). Toxicities were scored by the RTOG criteria. Results: With a median follow-up of 12.6 months (range: 4-34 months), 1- and 2-year actuarial LC was 66% and 44%, respectively. Overall survival was 56% at 1 year and 40% at 2 years. Both total dose and GTV were found to be predictive of LC. Nine local failures occurred at a dose of #48Gy, compared to one local failure at 60Gy (p = 0.009). An inverse correlation (p = 0.018) was found between GTV and LC, as 80% of local failures occurred with a GTV of $25cc. Grade #2 pulmonary fibrosis and cough were the two most common adverse effects, occurring in 57% and 35% of patients, respectively. Grade #2 pneumonitis occurred in 28% of patients, with no statistically significant relationship between incidence of pneumonitis and prior TRT (p = 0.33). One Grade 3 (fibrosis) and no Grade 4 toxicities were reported. Pneumothorax occurred in 25% of patients who underwent fiducial placement. Conclusions: SBRT appears to be a reasonable and well-tolerated approach in the local management of recurrent NSCLC, especially when higher total doses are used. Our current practice is to deliver 60Gy in 3 fractions to low-volume thoracic recurrences whenever possible. Recurrent lesions .25cc may benefit from higher total doses or a non-SBRT treatment approach. Our preliminary results will need to be validated by prospective studies of SBRT in the recurrent setting so that more concrete practice guidelines can be established for the stereotactic treatment of recurrent NSCLC. Longer follow-up is required to determine the full extent of late effects in this mostly previously irradiated cohort. Author Disclosure: J.E. Costello, None; E.P. Finnerty, None; R.L. Deming, None; D.K. Strom, None; K.J. Bernstein, None; N.J. Bellville, None; C.M. Burgin, None; R.P. Jacobsen, None; D.R. Puri, None.
2680
Prophylactic Radiotherapy to Prevent Procedure Tract Metastasis in Malignant Pleural Mesothelioma
M. Froment1, E´ Fre´chette2, A. Dagnault1 1 De´partement de Radio-oncologie, L’Hoˆtel-Dieu de Que´bec, Centre Hospitalier Universitaire de Que´bec (CHUQ), Quebec, QC, Canada, 2De´partement de Chirurgie Thoracique, Institut Universitaire de Cardiologie Et De Pneumologie de l’Universite´ Laval, Quebec, QC, Canada
Purpose/Objective(s): Prophylactic radiotherapy to intervention sites (PIT) in malignant pleural mesothelioma has been used for several years. In the literature, the effectiveness of this technique is controversial. Thus, the aim of this study was to assess the effectiveness of PIT to prevent tumor seeding in a large cohort of patients with malignant pleural mesothelioma in chemotherapy era. Materials/Methods: We performed a retrospective review of the case files of a cohort of 299 patients undergoing or not PIT between June 1985 and March 2009. From this cohort, we excluded 128 patients for lack of follow-up (\1 month), histopathologically unproved or non-mesothelioma cancer at the biopsy. Moreover, we excluded patients who had undergone gross tumor resection. Results: Forty-eight patients (28%) received PIT and 123 patients (72%) did not receive this treatment. The median follow-up was 9.3 months and 73% of patients were following until dead. Chemotherapy was given in 32.7% of patients. Most patients have received a Cisplatin-pemetrexed regimen. Patients were irradiated with a median delay of 27 days after their chest instrumentation, most often thoracoscopy (82.6%). The median dose of PIT was 21Gy in 3 fractions with electrons or 6MV photons. The median field size was 63.45cm2. During follow-up, 6 patients (12.5%) in the PIT group had a tumor invasion of the skin compared to 40 patients (32.5%) in the group without PIT (p = 0.008). For all of the 6 patients in the PIT group, these tract metastases were in the radiotherapy field. Among these, 4 patients (66.7%) had pain secondary to their lesion. Three had additional radiotherapy treatment and 66.7% patients had a good response. Thirty patients (75%) in the group without PIT had pain secondary to their tract metastasis. Thirteen patients in this group had radiotherapy treatment and 64.3% had a good response. The median delay between the procedure and the tumor skin invasion was longer in the PIT group (5.03 vs. 3.83 months respectively). Moreover, the local progression free survival (LPFS) at the intervention site was better in the PIT group (p = 0.004). At 1 year, LPFS for the intervention sites was 86.0% with PIT and 63.4% without PIT. Furthermore, the cancer-specific survival (CSS) and the overall survival (OS) were better in the group with PIT. At 1 year, CSS was 66.9% with PIT and 45.5% without PIT (p = 0.035) and the OS was 66.8% and 40.4% respectively (p = 0.037). Conclusions: This study suggests that PIT in mesothelioma reduces the incidence of procedure tract metastasis, and should be offered to patients because the majority of these newly developed lesions are symptomatic. Moreover, PIT seems to improve the OS and the CSS. Finally, a radiotherapy treatment should be attempted in patients with symptomatic tract metastasis. Author Disclosure: M. Froment, None; E´. Fre´chette, None; A. Dagnault, None.