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24 oral Initial clinical results of inverse planned high dose rate interstitial implants for cervical cancer
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needles in selected involved parts of parametria allows for appropriate target coverage (even for extensive parametrial involvement) in large tumours with individual sparing of organs at the same time. Based on this preliminary experience this technique seems to offer a challenging treatment option for large tumours with insufficient remission after radiochemotherapy resulting in an excellent rate of local control according to preliminary experience. 24 oral
Initial clinical results of inverse planned high dose rate interstitial implants for cervical cancer
K. Huan.q ~, J. Pouliot ~, E. Lessard ~, V. Weinberg ~, J. Speight ~, L. Chen 2, I. Hsu ~ 1University of Cafifomia, San Francisco, Radiation Oncology, San Francisco, CA, U.S.A. 2University of California, San Francisco, Obstetrics, Gynecology & Reproductive Sciences, San Francisco, CA, U.S.A Purpose: To report the initial clinical outcome of cervical cancer patients treated with external beam radiotherapy (EBRT) and inverse planned high dose rate (HDR) interstitial implants. Methods and Materials: All patients with newly-diagnosed cervical cancer treated with inverse planned interstitial HDR brachytherapy between March 2001 and July 2003 were retrospectively reviewed. During this period, patients with locally advanced tumor extending beyond coverage of the intracavitary brachytherapy system and early stage disease with unfavourable anatomy were treated with interstitial HDR brachytherapy boost. Twenty-nine patients who were candidates for chemo-radiotherapy were treated with a cisptatin-based regimen. Most patients received 45 Gy to the whole pelvis and 50 Gy to the pelvic sidewalls. Brachytherapy was initiated during or shortly after the completion of EBRT. All implants were performed using a freehand transrectal ultrasound guided interstitial implant technique. All patients underwent CT based treatment planning and dwell time optimization using inverse planning simulated annealing (IPSA). HDR Iridium-192 brachytherapy was given in 2-5 fractions delivered in 6.0 to 9.5 Gy per fraction using 1-2 implants, with an interfraction interval of at least 6 hours. Results: Thirty-four patients were included in this analysis. The median follow up time was 14 months. AJCC Stage distribution was: Stage I (3), Stage II (5), Stage III (14), Stage IV (12). The local control rate at 2-year was 71%. The rates of regional failure and distant metastases at 2-year were 12% and 18%. The 2-year disease-specific and overall survival probabilities were 77% and 61%. For patients who received biologically effective doses using alpha/beta of 10 (BED10) > 85 Gy, 1 out 10 patients failed locally, whereas, 6 out of 24 patients who received < 85 Gy had local failures (p=0.11). There were two cases (6%) of grade 3 or 4 acute toxicities. One patient developed deep vein thrombosis and another patient developed a uterine abscess. One patient developed a fistula in the setting of local recurrence. No other grade 3 or 4 late toxicities have occurred. Conclusions: Interstitial HDR brachytherapy using a freehand technique and inverse planning is well tolerated with minimal acute and late complications. Although there was not a statistically significant difference, we recommend delivering a combined BED10 dose of at least 85 Gy for locally advanced cervical cancer.
Friday, May 14, 2004
$11
25 oral
Intercomparison of treatment concepts for 3D image guided brachytherapy of cervical carcinoma based on a GEC-ESTRO s t u d y protocol
S. Lan.q ~, A. Nulens z, E. Brio~, C. Kirisits 1, M. De Brabandere 2, I. Dumas 3, J. Dimopoulos ~, N. Wachter-Gerstne/, P. Petrow 4, E. Van Limbergene, C. Hale-Medea, R. PStte/ ~General Hospital Vienna, Department for Radiotherapy and Radiobiolegy, Vienna, Austria eUniversity Hospital Gasthuisberg, Department of Radiotherapy, Leuven, Belgium 31nstitut Gustave Roussy, Service de Curieth6rapie, Villejuif, France 4L "HSpital Cantonal Universitaire de Geneve, Service de Radiologie, Geneve, Switzerland Introduction: Based on historically evolved schools a wide range of different approaches exists for intracavitary brachytherapy of cervix cancer. Differences are related to applicator design, sources, dose rate and dose prescribing systems. A GEC ESTRO group is currently working on recommendations for reporting MR/CT image based brachytherapy of cervix cancer. We present a reporting protocol for dosimetric data and its application to patients treated at IGR Paris, University Hospital Gasthuisberg Leuven and University Hospital Vienna. Methods and Materials: One patient was selected in each center which had to fulfil the following requirements: 1. tumor stage FIGO lib; 2. maximum tumor width at time of diagnosis 56 cm; 3. maximum tumor width at time of brachytherapy (after external beam therapy) 1-2 cm. GTV, CTV high risk (CTV HR), CTV intermediate risk (CTV IR) and organs at risk were delineated at the time of each brachytherapy application on a set of transversal MR images with the applicator in place. CTV HR includes GTV, cervix and the presumed extracervical tumor extension at time of brachytherapy, CTV IR is based on the macroscopic tumor extension at time of diagnosis. The dose distribution was superimposed on the MR image set and dose volume histograms calculated to evaluate the dose that covers 100% and 90% of the target volumes (DI00, Dg0) and doses to specific absolute volumes (2cm 3) of organs at risk. To take dose rate effects into account dose values are biologically normalized to fractions of 2 Gy external beam therapy (equivalent to 50cGy/h LDR) applying the linear-quadratic model for sublethal damage repair. Biological model parameters are T~/z=l,5h, cd~=10Gy for the tumor and od~=3Gy for normal tissue. To investigate the pear shape of the 3D dose distribution for different applicator design and loading pattern the dimensions of the isodose through point A are reported. Results: All 3 patients were treated with concomitant cisplatin chemotherapy and external beam radiotherapy of 45 Gy in 1,8 Gy fractions prior to brachytherapy. The Paris patient was treated with an individualized moulded intravaginal applicator and intrauterine source. Dose ~rescription for brachytherapy was 15 Gy Cs-137 LDR to the CTV IR with a treatment time of 48h. The Leuven patient was treated with a Fletcher based tandem-ovoid applicator. 35 Gy were prescribed to the target volume given in 36 pulses Ir-192 PDR with a puls interval of 1 h and a puls time of 15,8 min. The Vienna patient was treated with a Stockholm based tandem-ring applicator. Prescribed dose for brachytherapy was 28 Gy to the CTV HR given in 4 fractions (7 Gy each) of Ir-192 HDR. Biologically weighted total doses from external beam therapy plus brachytherapy are listed.
needles in selected involved parts of parametria allows for appropriate target coverage (even for extensive parametrial involvement) in large tumours with individual sparing of organs at the same time. Based on this preliminary experience this technique seems to offer a challenging treatment option for large tumours with insufficient remission after radiochemotherapy resulting in an excellent rate of local control according to preliminary experience. 24 oral
Initial clinical results of inverse planned high dose rate interstitial implants for cervical cancer
K. Huan.q ~, J. Pouliot ~, E. Lessard ~, V. Weinberg ~, J. Speight ~, L. Chen 2, I. Hsu ~ 1University of Cafifomia, San Francisco, Radiation Oncology, San Francisco, CA, U.S.A. 2University of California, San Francisco, Obstetrics, Gynecology & Reproductive Sciences, San Francisco, CA, U.S.A Purpose: To report the initial clinical outcome of cervical cancer patients treated with external beam radiotherapy (EBRT) and inverse planned high dose rate (HDR) interstitial implants. Methods and Materials: All patients with newly-diagnosed cervical cancer treated with inverse planned interstitial HDR brachytherapy between March 2001 and July 2003 were retrospectively reviewed. During this period, patients with locally advanced tumor extending beyond coverage of the intracavitary brachytherapy system and early stage disease with unfavourable anatomy were treated with interstitial HDR brachytherapy boost. Twenty-nine patients who were candidates for chemo-radiotherapy were treated with a cisptatin-based regimen. Most patients received 45 Gy to the whole pelvis and 50 Gy to the pelvic sidewalls. Brachytherapy was initiated during or shortly after the completion of EBRT. All implants were performed using a freehand transrectal ultrasound guided interstitial implant technique. All patients underwent CT based treatment planning and dwell time optimization using inverse planning simulated annealing (IPSA). HDR Iridium-192 brachytherapy was given in 2-5 fractions delivered in 6.0 to 9.5 Gy per fraction using 1-2 implants, with an interfraction interval of at least 6 hours. Results: Thirty-four patients were included in this analysis. The median follow up time was 14 months. AJCC Stage distribution was: Stage I (3), Stage II (5), Stage III (14), Stage IV (12). The local control rate at 2-year was 71%. The rates of regional failure and distant metastases at 2-year were 12% and 18%. The 2-year disease-specific and overall survival probabilities were 77% and 61%. For patients who received biologically effective doses using alpha/beta of 10 (BED10) > 85 Gy, 1 out 10 patients failed locally, whereas, 6 out of 24 patients who received < 85 Gy had local failures (p=0.11). There were two cases (6%) of grade 3 or 4 acute toxicities. One patient developed deep vein thrombosis and another patient developed a uterine abscess. One patient developed a fistula in the setting of local recurrence. No other grade 3 or 4 late toxicities have occurred. Conclusions: Interstitial HDR brachytherapy using a freehand technique and inverse planning is well tolerated with minimal acute and late complications. Although there was not a statistically significant difference, we recommend delivering a combined BED10 dose of at least 85 Gy for locally advanced cervical cancer.
Friday, May 14, 2004
$11
25 oral
Intercomparison of treatment concepts for 3D image guided brachytherapy of cervical carcinoma based on a GEC-ESTRO s t u d y protocol
S. Lan.q ~, A. Nulens z, E. Brio~, C. Kirisits 1, M. De Brabandere 2, I. Dumas 3, J. Dimopoulos ~, N. Wachter-Gerstne/, P. Petrow 4, E. Van Limbergene, C. Hale-Medea, R. PStte/ ~General Hospital Vienna, Department for Radiotherapy and Radiobiolegy, Vienna, Austria eUniversity Hospital Gasthuisberg, Department of Radiotherapy, Leuven, Belgium 31nstitut Gustave Roussy, Service de Curieth6rapie, Villejuif, France 4L "HSpital Cantonal Universitaire de Geneve, Service de Radiologie, Geneve, Switzerland Introduction: Based on historically evolved schools a wide range of different approaches exists for intracavitary brachytherapy of cervix cancer. Differences are related to applicator design, sources, dose rate and dose prescribing systems. A GEC ESTRO group is currently working on recommendations for reporting MR/CT image based brachytherapy of cervix cancer. We present a reporting protocol for dosimetric data and its application to patients treated at IGR Paris, University Hospital Gasthuisberg Leuven and University Hospital Vienna. Methods and Materials: One patient was selected in each center which had to fulfil the following requirements: 1. tumor stage FIGO lib; 2. maximum tumor width at time of diagnosis 56 cm; 3. maximum tumor width at time of brachytherapy (after external beam therapy) 1-2 cm. GTV, CTV high risk (CTV HR), CTV intermediate risk (CTV IR) and organs at risk were delineated at the time of each brachytherapy application on a set of transversal MR images with the applicator in place. CTV HR includes GTV, cervix and the presumed extracervical tumor extension at time of brachytherapy, CTV IR is based on the macroscopic tumor extension at time of diagnosis. The dose distribution was superimposed on the MR image set and dose volume histograms calculated to evaluate the dose that covers 100% and 90% of the target volumes (DI00, Dg0) and doses to specific absolute volumes (2cm 3) of organs at risk. To take dose rate effects into account dose values are biologically normalized to fractions of 2 Gy external beam therapy (equivalent to 50cGy/h LDR) applying the linear-quadratic model for sublethal damage repair. Biological model parameters are T~/z=l,5h, cd~=10Gy for the tumor and od~=3Gy for normal tissue. To investigate the pear shape of the 3D dose distribution for different applicator design and loading pattern the dimensions of the isodose through point A are reported. Results: All 3 patients were treated with concomitant cisplatin chemotherapy and external beam radiotherapy of 45 Gy in 1,8 Gy fractions prior to brachytherapy. The Paris patient was treated with an individualized moulded intravaginal applicator and intrauterine source. Dose ~rescription for brachytherapy was 15 Gy Cs-137 LDR to the CTV IR with a treatment time of 48h. The Leuven patient was treated with a Fletcher based tandem-ovoid applicator. 35 Gy were prescribed to the target volume given in 36 pulses Ir-192 PDR with a puls interval of 1 h and a puls time of 15,8 min. The Vienna patient was treated with a Stockholm based tandem-ring applicator. Prescribed dose for brachytherapy was 28 Gy to the CTV HR given in 4 fractions (7 Gy each) of Ir-192 HDR. Biologically weighted total doses from external beam therapy plus brachytherapy are listed.