- Email: [email protected]
A Comparative Study of PET-CT Fusion versus PET-CT Simulation for Target Delineation in Non-small Cell Lung Cancer
Proceedings of the 52nd Annual ASTRO Meeting
2758
Results of Stereotactic Body Radiation Therapy with CyberKnife for Medically Inoperable Stage I Non-small Cell Carcinoma of the Lung
S. Hoffelt, E. Kim, R. Karmy-Jones, C. Jackson, S. Colliander Southwest Washington Medical Center, Vancouver, WA Purpose/Objective(s): To study the outcome of stereotactic body radiation therapy (SBRT) using CyberKnife for medically inoperable stage I non-small cell carcinoma of the lung. Materials/Methods: From September 2006 to September 2009, 46 Patients with biopsy confirmed stage I non-small cell carcinoma of the lung were treated with SBRT using the CyberKnife system. All patients were considered poor candidates for surgical resection. Stage was T1N0 in 33 patients (72%) and T2N0 in 13 patients (28%). Most tumors (93%) were peripheral by RTOG criteria. Planning tumor volume (PTV) was the gross tumor visible on CT scan plus 1cm margin excluding chest wall and mediastinum. Dose was prescribed to the highest isodose line encompassing at least 95% of the PTV (range, 60-90%). Dose was 12-60 Gy in 1-6 fractions, most commonly 60 Gy in 3 fractions. Fiducial markers, tumor, or spine anatomy was used for tracking and delivery. Two patients had received prior XRT for previous unrelated cancers. Three patients received adjuvant chemotherapy within 4 months of treatment. Results: At a median follow-up of 23 months (range, 2-41 months), Kaplan-Meier local control was 95%, with 1 local recurrence 2 cm from the primary tumor and 1 within the planning volume of a central tumor. Two year overall survival (OS) was 83%, disease free survival was 75%. Six patients have died, 4 due to illness not related to lung cancer or SBRT. Median survival has not been reached. The dominant pattern of recurrence was distant metastasis in 6 patients (13%), followed by local recurrence only in 2 (4%), hilar recurrence in 1 (2%). Acute toxicity was grade 1 to 2 only in 46%, most commonly temporary fatigue. There was no grade 3 to 5 acute toxicity. Late toxicity was grade 3 in 2/46 patients (4%), including temporary chest wall pain and one pneumothorax 15 and18 months after treatment, respectively. There was no grade 4 or 5 toxicity. Grade 1 to 2 late toxicity included pleural effusion (4%), chronic rib pain (4%), and cough (1%). Conclusions: SBRT with CyberKnife is a very effective, safe treatment for stage I non-small cell carcinoma of the lung in medically inoperable patients. Author Disclosure: S. Hoffelt, None; E. Kim, None; R. Karmy-Jones, None; C. Jackson, None; S. Colliander, None.
2759
A Comparative Study of PET-CT Fusion versus PET-CT Simulation for Target Delineation in Non-small Cell Lung Cancer
A. Lin, K. Teo, R. Rengan University of Pennsylvania, Philadelphia, PA Purpose/Objective(s): Delineation of tumor volume on axial CT images has been the established standard for radiation treatment planning. However, there is an emerging role in the use of PET images for target definition. The purpose of this study is to compare the accuracy of PET-based target definition from fusion of PET images to treatment planning CT versus simultaneous PET/CT simulation. Materials/Methods: With IRB approval, we retrospectively reviewed a total of 18 patients, 8 who underwent diagnostic PET (obtained in treatment planning position) which was fused to a treatment planning CT, and 10 who underwent PET-CT simulation (Philips Gemini TF Big Bore system). On each patient, the primary lung tumor was contoured twice, once on a CT dataset to generate a CT-based GTV (GTV-CT) and once on a PET dataset to generate a PET-based GTV (GTV-PET). GTV-PET was generated using an auto-contour function, using a threshold of 43% SUVmax. The following variables were obtained: GTV-CT volume, GTV-PET volume, percent volume of GTV-PET within GTV-CT, and percent volume GTVPET outside of GTV-CT. Results: Patients in both groups had locally advanced (stage IIIA/B) or metastatic (stage IV) disease at time of simulation, with no appreciable differences in volume of the primary tumor between the groups. The average GTV-PET was significantly smaller than GTV-CT, regardless of whether PET was fused or obtained simultaneously (19 cc vs. 61 cc, p \ 0.001). The percent volume of GTV-PET within GTV-CT was . 90% for both methods (97% for PET-CT fusion vs. 91% for PET-CT simulation, p = 0.3). The percent volume of GTV-PET outside of GTV-CT was \ 10% for both groups (3% for PET-CT fusion vs. 9% for PET-CT simulation, p = 0.3). Conclusions: PET acquired in treatment planning position and fused to a treatment planning CT dataset appears to be as reliable as PET-CT simulation in defining the primary gross tumor volume in non-small cell lung cancer. PET-defined gross tumor volume was significantly smaller than CT-defined disease. Other thresholds for PET-autocontouring need to be explored before PET should be routinely incorporated into radiation target delineation, which is a focus of ongoing study. Author Disclosure: A. Lin, None; K. Teo, None; R. Rengan, None.
2760
Quality Control of Involved Field (IF)-radiotherapy for Patients with Early-stage Hodgkin Lymphoma Based on a Central Prospective Review: Comparison of the Results between Two Study Generations of the German Hodgkin Study Group (GHSG)
J. Kriz1, R. P. Mueller1, C. Bangard2, R. Bongartz1, A. Engert3, H. T. Eich1 1 Dept. of Radiation Oncology, University of Cologne, Germany, 2Dept. of Radiology, University of Cologne, Germany, 3First Dept. of Internal Medicine, University of Cologne, Germany
Purpose/Objective(s): Based on the experiences within the trials HD10 and HD11 (1998-2003), the radiotherapy reference center of the GHSG continued their central prospective radiation oncologic review of all patients’ diagnostic imaging and clinical findings within the trials HD13 and HD14. An individual RT prescription was provided for every study patient. The purpose of this analysis was to identify the impact of this procedure onto the radiotherapeutic management and to compare the findings with the former trials.
S543
2758
Results of Stereotactic Body Radiation Therapy with CyberKnife for Medically Inoperable Stage I Non-small Cell Carcinoma of the Lung
S. Hoffelt, E. Kim, R. Karmy-Jones, C. Jackson, S. Colliander Southwest Washington Medical Center, Vancouver, WA Purpose/Objective(s): To study the outcome of stereotactic body radiation therapy (SBRT) using CyberKnife for medically inoperable stage I non-small cell carcinoma of the lung. Materials/Methods: From September 2006 to September 2009, 46 Patients with biopsy confirmed stage I non-small cell carcinoma of the lung were treated with SBRT using the CyberKnife system. All patients were considered poor candidates for surgical resection. Stage was T1N0 in 33 patients (72%) and T2N0 in 13 patients (28%). Most tumors (93%) were peripheral by RTOG criteria. Planning tumor volume (PTV) was the gross tumor visible on CT scan plus 1cm margin excluding chest wall and mediastinum. Dose was prescribed to the highest isodose line encompassing at least 95% of the PTV (range, 60-90%). Dose was 12-60 Gy in 1-6 fractions, most commonly 60 Gy in 3 fractions. Fiducial markers, tumor, or spine anatomy was used for tracking and delivery. Two patients had received prior XRT for previous unrelated cancers. Three patients received adjuvant chemotherapy within 4 months of treatment. Results: At a median follow-up of 23 months (range, 2-41 months), Kaplan-Meier local control was 95%, with 1 local recurrence 2 cm from the primary tumor and 1 within the planning volume of a central tumor. Two year overall survival (OS) was 83%, disease free survival was 75%. Six patients have died, 4 due to illness not related to lung cancer or SBRT. Median survival has not been reached. The dominant pattern of recurrence was distant metastasis in 6 patients (13%), followed by local recurrence only in 2 (4%), hilar recurrence in 1 (2%). Acute toxicity was grade 1 to 2 only in 46%, most commonly temporary fatigue. There was no grade 3 to 5 acute toxicity. Late toxicity was grade 3 in 2/46 patients (4%), including temporary chest wall pain and one pneumothorax 15 and18 months after treatment, respectively. There was no grade 4 or 5 toxicity. Grade 1 to 2 late toxicity included pleural effusion (4%), chronic rib pain (4%), and cough (1%). Conclusions: SBRT with CyberKnife is a very effective, safe treatment for stage I non-small cell carcinoma of the lung in medically inoperable patients. Author Disclosure: S. Hoffelt, None; E. Kim, None; R. Karmy-Jones, None; C. Jackson, None; S. Colliander, None.
2759
A Comparative Study of PET-CT Fusion versus PET-CT Simulation for Target Delineation in Non-small Cell Lung Cancer
A. Lin, K. Teo, R. Rengan University of Pennsylvania, Philadelphia, PA Purpose/Objective(s): Delineation of tumor volume on axial CT images has been the established standard for radiation treatment planning. However, there is an emerging role in the use of PET images for target definition. The purpose of this study is to compare the accuracy of PET-based target definition from fusion of PET images to treatment planning CT versus simultaneous PET/CT simulation. Materials/Methods: With IRB approval, we retrospectively reviewed a total of 18 patients, 8 who underwent diagnostic PET (obtained in treatment planning position) which was fused to a treatment planning CT, and 10 who underwent PET-CT simulation (Philips Gemini TF Big Bore system). On each patient, the primary lung tumor was contoured twice, once on a CT dataset to generate a CT-based GTV (GTV-CT) and once on a PET dataset to generate a PET-based GTV (GTV-PET). GTV-PET was generated using an auto-contour function, using a threshold of 43% SUVmax. The following variables were obtained: GTV-CT volume, GTV-PET volume, percent volume of GTV-PET within GTV-CT, and percent volume GTVPET outside of GTV-CT. Results: Patients in both groups had locally advanced (stage IIIA/B) or metastatic (stage IV) disease at time of simulation, with no appreciable differences in volume of the primary tumor between the groups. The average GTV-PET was significantly smaller than GTV-CT, regardless of whether PET was fused or obtained simultaneously (19 cc vs. 61 cc, p \ 0.001). The percent volume of GTV-PET within GTV-CT was . 90% for both methods (97% for PET-CT fusion vs. 91% for PET-CT simulation, p = 0.3). The percent volume of GTV-PET outside of GTV-CT was \ 10% for both groups (3% for PET-CT fusion vs. 9% for PET-CT simulation, p = 0.3). Conclusions: PET acquired in treatment planning position and fused to a treatment planning CT dataset appears to be as reliable as PET-CT simulation in defining the primary gross tumor volume in non-small cell lung cancer. PET-defined gross tumor volume was significantly smaller than CT-defined disease. Other thresholds for PET-autocontouring need to be explored before PET should be routinely incorporated into radiation target delineation, which is a focus of ongoing study. Author Disclosure: A. Lin, None; K. Teo, None; R. Rengan, None.
2760
Quality Control of Involved Field (IF)-radiotherapy for Patients with Early-stage Hodgkin Lymphoma Based on a Central Prospective Review: Comparison of the Results between Two Study Generations of the German Hodgkin Study Group (GHSG)
J. Kriz1, R. P. Mueller1, C. Bangard2, R. Bongartz1, A. Engert3, H. T. Eich1 1 Dept. of Radiation Oncology, University of Cologne, Germany, 2Dept. of Radiology, University of Cologne, Germany, 3First Dept. of Internal Medicine, University of Cologne, Germany
Purpose/Objective(s): Based on the experiences within the trials HD10 and HD11 (1998-2003), the radiotherapy reference center of the GHSG continued their central prospective radiation oncologic review of all patients’ diagnostic imaging and clinical findings within the trials HD13 and HD14. An individual RT prescription was provided for every study patient. The purpose of this analysis was to identify the impact of this procedure onto the radiotherapeutic management and to compare the findings with the former trials.
S543