- Email: [email protected]
O-22 Megavoltage CT imaging for image-guided lung cancer intensity modulated radiation therapy (IMRT)
Oral Sessions/Radiotheru~y Treatment Planning
SIO
for stereotactic precision therapy for extracranial tumours using a linear accelerator and a stereotactic body frame has been developed at the Karolinska Hospital in Stockholm. This was applied in an attempt to improve the local control for consecutive patients with inoperable stage I NSCLC at Sahlgrenska University Hospital since September 1998. Methods: With this precise fixation, we used a planning target volume (PTV) with a 0.5 cm margin around the tumour in the transversal plane and 1.0 cm in crania-caudal direction. 4-7 coplanar or non-coplanar fields were used and the dose was prescribed in the periphery of the PTV (about 140% in the centre). Radiotherapy was delivered in three fractions of 15 Gy to 45 Gy during one week. Results: Forty-four patients were treated between Sept-98 and Jan-03, 24 men and 20 women, median age 74 (58-84) and Karnofsky 80 (100-60). Surgery was excluded due to: poor lung function (30), cardiovascular disease (23), other malignancy (5) and refusal (2). TNM classification: 18 TlNO, 24 T2NO and two small local recurrences. Histology: 18 squamous cell carcinomas, 14 adenocarcinomas, 2 large cell carcinomas and missing in 9 patients. Toxicity: 21 patients did not experience any toxicity at all, 4 had esophagitis grade I, 7 skin reactions, 4 pneumonia and 2 transient pain. Response: CT-scans after 3 months showed 31 PR, 8 SD, 4 NE and one patient had progressive disease. Survival: one, two and three-year overall survival were 86%, 76% and 59%, respectively. Median survival is not reached, median follow up is 19 months. Conclusion: This study with stereotactic radiotherapy for patients with stage I NSCLC shows a high response rate and survival combined with low toxicity. The study will be followed by a randomized Scandinavian trial.
El0 21
IMRT approaches. In particular, dose reconstruction via MVCT will enable the radiation oncologist to make adjustments to the radiotherapy plan if necessary. Objective: To prospectively evaluate the feasibility and utility of MVCT in patients with lung cancer. Methods: Ten patients with lung cancer underwent conventional contrastenhanced kilovoltage CT (KVCT) imaging for treatment planning followed by non-contrast-enhanced MVCT in the same position, using the helical tomotherapy unit. After fusion of the two CT datasets, four independent observers subjectively and objectively compared the images. Subjectively, the tumors were scored on a 1 (worst) - 5 (best) visual analog scale, and objectively, volumetric change was assessed. Results: 7/10 patients had the bulk of their lesion in the pulmonary parenchyma, 2 in the mediastinum (or with considerable lung collapse) and 1 in both. Overall, i/IO, 2/10, i/IO and l/IO patients’ MVCT scans were rated as inadequate for volumetric assessment by the four observers; subjectively, g/IO, 7/10, 9/10 and 8/l 0 received a score of p 3. of the patients evaluable for volumetric assessment, the individual and average agreement using varying volumetric thresholds is presented below (figure 1). When evaluated by location, all 7 patients with lesions primarily in the lung had high quality MVCT with exquisite detail visible (figure 2); additionally, the volumetric agreement between observers in patients with parenchymal lesions was excellent in 5/7. 100
Stereotactic Body Frame Based Fractionated Radiosurgery on Consecutive Days for lntrathoracic Tumors: Preliminary Results of a Phase VII Study
Eun Kvunq Choi, Sang-Wook Lee, Seung Do Ahn, Jong Hoon Kim, Byong Yong Yi. Department of Radiation Oncology: Asan Medical Center, University of U&n, Seoul, Korea
Purpose: To evaluate the feasibility and treatment outcomes of 3-D conformal MLC-based
stereotactic
radiosurgery
(SRS) using a stereotactic
5%
body frame.
Methods and Materials: From January 1998 to September 2002,51 patients with primary or metastatic lung tumors were entered into this study. Eligible patients included were 20 with primary lung cancer and 31 with metastatic tumors from the lung, liver, and many other organs. A single dose of IO Gy to the clinical target volume (CTV) was delivered to a total dose of 30-40 Gy with 3-4 fractions. Four to 8 coplanar or non-coplanar static fields were generated to adequately cover the planning target volume (PTV) as well as to exclude the critical structures as much as possible. More than 90% of the PTV was delivered the prescribed dose in the majority of cases (average; 96%, range; 74%-100%). The mean PTV was 32 cc ranging from 1.9 to 230~~. Set-up error was within 5 m m in all directions (X, Y, Z axis). Results: The response was evaluated by using a chest CT and/or 18FDGPET scans after SRS treatment, 17 patients (33%) showed complete response, 25 (45%) partial response (decrease of more than 50% of the tumor volume), and 8 patients showed minimally decreased tumor volume or stable disease, but only 1 patient showed progressive disease. With a median follow-up period of 15 months, a local disease progression free interval was ranging from 4 to 40 months. Five of 50 patients who showed CR, PR and NR were observed locally progression after SRS later than 3 months. Local disease progression free and overall survival rates were 80% and 43% respectively. Although all patients developed grade 1 radiation pneumonitis within 3 months, none had symptomatic or serious late complications after completing SRS treatment. Conclusions: The preliminary experience of the stereotactic body frame based SRS appeared safe and promising treatment modality for the local management of primary or metastatic lung tumors. However, the optimum total dose and fractionation schedule used should be determined after the longer follow-up of these results.
0 22 El
Megavoltage CT Imaging for Image-guided Lung Cancer Intensity Modulated Radiation Therapy (IMRT)
Kristin Bradley’, Rafael MaRon’ , Rakesh Patel’, Doug Hendersor?, Peggy Wiederholt’ , Minesh Mehta’ , James Welsh’. ’ University of Wisconsin-Madison, Madison, USA; ’ Tomotherapy, Inc, Madison, USA
Introduction: With the advent of IMRT, image-guided
delivery has acquired major significance. Helical tomotherapy is an innovative means of delivering IMRT. Integral to tomotherapy is the capacity for image guidance through Megavoltage Computed Tomography (MVCT). MVCT offers: 1. CT verification of patient position prior to and during radiation therapy; 2. more detailed anatomic information than is possible with conventional “port films” that currently are used for patient set-up verification; and 3. dose reconstruction of actual radiation dose delivered. These key features of tomotherapy distinguish it from other
10% 15% Threshold
20% 25% Volume
30%
Fig. 1.
Fig. 2
Conclusions: Helical tomotherapy MVCT imaging provides adequate tumor localization information for use in CT verification of patient position and dose reconstruction for lesions within the pulmonary parenchyma, but appears to be suboptimal for primarily mediastinal disease. Further study to address this is underway. 1
Intensity-modulated lesions
hypofractionated
radioablation
for lung
Martin Fuss’, Bill J. Salter’, Michael Selva2, Charles R. Thomas Jr.2. ’ Universtity of Texas Health Science Center at San Antonio, Radiation Oncology San Antonio, USA; 2 University of Texas Health Science Center at San Antonio, Radiation Oncology, San Antonio, USA
Purpose: To present intensity-modulated extracranial radioablation (ECRA) techniques for lung lesions. To present preliminary clinical outcomes and to discuss future potential of the technique.
SIO
for stereotactic precision therapy for extracranial tumours using a linear accelerator and a stereotactic body frame has been developed at the Karolinska Hospital in Stockholm. This was applied in an attempt to improve the local control for consecutive patients with inoperable stage I NSCLC at Sahlgrenska University Hospital since September 1998. Methods: With this precise fixation, we used a planning target volume (PTV) with a 0.5 cm margin around the tumour in the transversal plane and 1.0 cm in crania-caudal direction. 4-7 coplanar or non-coplanar fields were used and the dose was prescribed in the periphery of the PTV (about 140% in the centre). Radiotherapy was delivered in three fractions of 15 Gy to 45 Gy during one week. Results: Forty-four patients were treated between Sept-98 and Jan-03, 24 men and 20 women, median age 74 (58-84) and Karnofsky 80 (100-60). Surgery was excluded due to: poor lung function (30), cardiovascular disease (23), other malignancy (5) and refusal (2). TNM classification: 18 TlNO, 24 T2NO and two small local recurrences. Histology: 18 squamous cell carcinomas, 14 adenocarcinomas, 2 large cell carcinomas and missing in 9 patients. Toxicity: 21 patients did not experience any toxicity at all, 4 had esophagitis grade I, 7 skin reactions, 4 pneumonia and 2 transient pain. Response: CT-scans after 3 months showed 31 PR, 8 SD, 4 NE and one patient had progressive disease. Survival: one, two and three-year overall survival were 86%, 76% and 59%, respectively. Median survival is not reached, median follow up is 19 months. Conclusion: This study with stereotactic radiotherapy for patients with stage I NSCLC shows a high response rate and survival combined with low toxicity. The study will be followed by a randomized Scandinavian trial.
El0 21
IMRT approaches. In particular, dose reconstruction via MVCT will enable the radiation oncologist to make adjustments to the radiotherapy plan if necessary. Objective: To prospectively evaluate the feasibility and utility of MVCT in patients with lung cancer. Methods: Ten patients with lung cancer underwent conventional contrastenhanced kilovoltage CT (KVCT) imaging for treatment planning followed by non-contrast-enhanced MVCT in the same position, using the helical tomotherapy unit. After fusion of the two CT datasets, four independent observers subjectively and objectively compared the images. Subjectively, the tumors were scored on a 1 (worst) - 5 (best) visual analog scale, and objectively, volumetric change was assessed. Results: 7/10 patients had the bulk of their lesion in the pulmonary parenchyma, 2 in the mediastinum (or with considerable lung collapse) and 1 in both. Overall, i/IO, 2/10, i/IO and l/IO patients’ MVCT scans were rated as inadequate for volumetric assessment by the four observers; subjectively, g/IO, 7/10, 9/10 and 8/l 0 received a score of p 3. of the patients evaluable for volumetric assessment, the individual and average agreement using varying volumetric thresholds is presented below (figure 1). When evaluated by location, all 7 patients with lesions primarily in the lung had high quality MVCT with exquisite detail visible (figure 2); additionally, the volumetric agreement between observers in patients with parenchymal lesions was excellent in 5/7. 100
Stereotactic Body Frame Based Fractionated Radiosurgery on Consecutive Days for lntrathoracic Tumors: Preliminary Results of a Phase VII Study
Eun Kvunq Choi, Sang-Wook Lee, Seung Do Ahn, Jong Hoon Kim, Byong Yong Yi. Department of Radiation Oncology: Asan Medical Center, University of U&n, Seoul, Korea
Purpose: To evaluate the feasibility and treatment outcomes of 3-D conformal MLC-based
stereotactic
radiosurgery
(SRS) using a stereotactic
5%
body frame.
Methods and Materials: From January 1998 to September 2002,51 patients with primary or metastatic lung tumors were entered into this study. Eligible patients included were 20 with primary lung cancer and 31 with metastatic tumors from the lung, liver, and many other organs. A single dose of IO Gy to the clinical target volume (CTV) was delivered to a total dose of 30-40 Gy with 3-4 fractions. Four to 8 coplanar or non-coplanar static fields were generated to adequately cover the planning target volume (PTV) as well as to exclude the critical structures as much as possible. More than 90% of the PTV was delivered the prescribed dose in the majority of cases (average; 96%, range; 74%-100%). The mean PTV was 32 cc ranging from 1.9 to 230~~. Set-up error was within 5 m m in all directions (X, Y, Z axis). Results: The response was evaluated by using a chest CT and/or 18FDGPET scans after SRS treatment, 17 patients (33%) showed complete response, 25 (45%) partial response (decrease of more than 50% of the tumor volume), and 8 patients showed minimally decreased tumor volume or stable disease, but only 1 patient showed progressive disease. With a median follow-up period of 15 months, a local disease progression free interval was ranging from 4 to 40 months. Five of 50 patients who showed CR, PR and NR were observed locally progression after SRS later than 3 months. Local disease progression free and overall survival rates were 80% and 43% respectively. Although all patients developed grade 1 radiation pneumonitis within 3 months, none had symptomatic or serious late complications after completing SRS treatment. Conclusions: The preliminary experience of the stereotactic body frame based SRS appeared safe and promising treatment modality for the local management of primary or metastatic lung tumors. However, the optimum total dose and fractionation schedule used should be determined after the longer follow-up of these results.
0 22 El
Megavoltage CT Imaging for Image-guided Lung Cancer Intensity Modulated Radiation Therapy (IMRT)
Kristin Bradley’, Rafael MaRon’ , Rakesh Patel’, Doug Hendersor?, Peggy Wiederholt’ , Minesh Mehta’ , James Welsh’. ’ University of Wisconsin-Madison, Madison, USA; ’ Tomotherapy, Inc, Madison, USA
Introduction: With the advent of IMRT, image-guided
delivery has acquired major significance. Helical tomotherapy is an innovative means of delivering IMRT. Integral to tomotherapy is the capacity for image guidance through Megavoltage Computed Tomography (MVCT). MVCT offers: 1. CT verification of patient position prior to and during radiation therapy; 2. more detailed anatomic information than is possible with conventional “port films” that currently are used for patient set-up verification; and 3. dose reconstruction of actual radiation dose delivered. These key features of tomotherapy distinguish it from other
10% 15% Threshold
20% 25% Volume
30%
Fig. 1.
Fig. 2
Conclusions: Helical tomotherapy MVCT imaging provides adequate tumor localization information for use in CT verification of patient position and dose reconstruction for lesions within the pulmonary parenchyma, but appears to be suboptimal for primarily mediastinal disease. Further study to address this is underway. 1
Intensity-modulated lesions
hypofractionated
radioablation
for lung
Martin Fuss’, Bill J. Salter’, Michael Selva2, Charles R. Thomas Jr.2. ’ Universtity of Texas Health Science Center at San Antonio, Radiation Oncology San Antonio, USA; 2 University of Texas Health Science Center at San Antonio, Radiation Oncology, San Antonio, USA
Purpose: To present intensity-modulated extracranial radioablation (ECRA) techniques for lung lesions. To present preliminary clinical outcomes and to discuss future potential of the technique.