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946 poster Clinical results of patients with prostate cancer treated with intensitiy modulated radiotherapy
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coverage of 1.2-2.7%, 2.8-5.0%, and 3.8-6.3% at V40, V47.5, and V50, respectively, and the degree of underdosing was proportional to the extent of shielding. On the other hand, shielding the rectum provided an absolute benefit in rectal sparing of 21.9-27.5%, 10.9-11.6%, and 5.1-5.4% at V50, V60, and V70, respectively. However, WP IMRT provided superior sparing of both bladder and rectum over each 4FBT plan. For the rectum, the advantage was around 10% at V70 and even greater at lower doses. Average NTCP values for Grade 2+ toxicity were 9.4-14.6% and 5.4% for 4FBT and WP IMRT, respectively. When examining the total number of plans that met rectal dose-volume objectives, 90% (86/96) met objectives with WP IMRT as compared to 48% (46/96) with 4FBT. Conclusion: Rectal shielding on the lateral fields of the 4FBT resulted in improvements in rectal dose points as compared to 4FBT with no rectal shielding. However, the improvements came at the expense of PLN PTV coverage. WP IMRT is, however, under each dosimetric endpoint investigated, superior to 4FBT and allows dose escalation to the prostate while respecting current dose objectives in the majority of patients. 946 poster Clinical results of patients with prostate cancer treated with intensitiy modulated radiotherapy
D. Boehmer ~, R. Herschel ~, J. Bohsung 2, L Eichwurzef, H. Badakhshi 1, V. Budach ~ ~Charite Campus Mitte, Dept. of Radiation Oncology, Berlin, Germany ;Charit~ Campus Mitte, Dept. of Radiation Oncology-Physics Dept., Berlin, Germany Methods and Material: Between September 2000 and September 2003 ninety-six patients with prostate cancer where treated with intensity modulated radiotherapy. Tlc, T2a, T2b, T2c and T3a tumours were found in 38, 27, 17, 2, and 11 patients, respectively. One patient presented with a suspicious T4 tumour (infiltration of bladder neck according to MRI). In most patients a Gleason Score of 2-6 (77.1%) was detected. 14 patients (14.6%) and 8 patients (8.3%) presented with a Gleason Score 7 and 8-10, respectively. Pretreatment PSA level < 10 ng/ml, 10-20 ng/ml and > 20 ng/ml where determined in 67, 25 and 4 patients. Mean RT dose was 79.8 Gy (range 74 Gy -82 Gy). The treatment technique for all patients consisted of an arrangement of 5 intensity modulated fields using the SIB technique (Simultaneous Integrated Boost) with dynamic Multi-LeafCollimators. Toxicity was evaluated using the Common Toxicity Criteria version 2.0. Results: Treatment was completed without interruption in all IMRT patients. For the first 20 patients we performed daily electronic portal imaging. The standard deviation o f the lateral, cranio-caudal and anterior-posterior set-up errors was 2.8, 2.2 and 1.9 mm, respectively. 95% of all treatments were within a + 5 mm margin from the isocentre. Throughout the treatment course of twenty patients with 1640 electronic portal images only 64 treatment sessions had to be interrupted to perform an on-line set-up correction. None of the patients experienced grade 4 acute side effects. Grade 3 side effects were rare with 1%, 2% and 1% of all patients experiencing painful urination, an increase of urinary frequency and diarrhea, respectively. The most frequent acute GU side effects were mild and moderate painful urination (44% and 11%), increased urinary frequency (34% and 10%) and nocturnal urination (47% and 7%). Mild and moderate GI acute side effects were rectal pain (27% and 3%), increase in stool frequency (36% and 2%), rectal
Posters
mucositis (34% and 4%) with blood-streaked stool in 14% of all patients. So far no late radiation toxicity grade 3 or 4 has been observed. Conclusion: IMRT of prostate cancer is feasible and results in a low rate of acute side effects. So far the rate of late radiation toxicity is low although the follow-up is still too short. The results of set-up deviation are in good agreement with the literature. 947 poster A prospective study of erectile dysfunction & its effect on quality of life after prostate brachytherapy
A. Henderson ~, P. Sooriakumaran ~, S.en.E.M LangleS, R.rt. W Laing 2 ~St.Luke's Cancer Center, Urology, Guildford, United Kingdom 2St.Luke's Cancer Center, Oncology, Guildford, United Kingdom Introduction: We assess the effect of brachytherapy on potency and quality of life in a prospective, patient administered questionnaire study. Patients and methods: Patients completed the International Index of Erectile Function (IIEF-5) prior to brachytherapy and at 6 weeks, 3,6,9,12,18 and 24 months post implant. Patients who considered that they had erectile problems completed the ED effect on Quality of Life (EDQol) questionnaire. Men with an IIEF-5 score of <12/25 (moderate-severe ED) were considered impotent. Result: 153 patients completed baseline and >1 postimplant IIEF-5 questionnaire, 39% (n=60) were potent pre-implant. 67% of potent patients maintained potency at last follow up (mean FU 15m). Potency rates improved over time postimplant 6wk-47%, 3m-56%, 6m-48%, 9m-63%, 12m56%, 18m-75%. Of 93 patients impotent at baseline 63% completed the EDQuol; 15% reported no effect on quality of life, 39% mild effect, 30% moderate effect and 16% a severe effect. In patients who were impotent as a result of treatment at the 6 month assessment 88% completed EDQuol; 7% had no effect on quality of life, 47% mild effect, 27% moderate effect and 20% a severe effect. Early potency after brachytherapy is encouraging and compares favourably with other modalities for the treatment of early prostate cancer. ED improves with time postbrachytherapy within the first 18 months. Patients experiencing impotence as a result of treatment are equally as likely to report moderate-severe ED effects on quality of life as those impotent before brachytherapy. 948 poster Use of gold markers for setup in fractionated HDR brachytherapy and organ tracking during iMRT in combined radiotherapy of prostate cancer
D.M. Aebersold, D. Vetterli 1, C. Kolotas 1, S. Thalmann 1, B. Isaak ~, G. Thalmann 2, L. Kemmerling ~, F. Behrensmeier 1, R. Mini I, R. Greiner 1 1University of Bern, Inselspital, Radiation Oncology, Bern, Switzerland 2University of Bern, Inselspital, Urology, Bern, Switzerland Objective:To investigate the use of gold markers for setup in combined radiotherapy of advanced prostate cancer. Material and Methods: 21 pts. with advanced prostate cancer were analysed who underwent combined HDR brachytherapy (BT; 3 x 7 Gy) and EBRT (IMRT, 50 Gy).
coverage of 1.2-2.7%, 2.8-5.0%, and 3.8-6.3% at V40, V47.5, and V50, respectively, and the degree of underdosing was proportional to the extent of shielding. On the other hand, shielding the rectum provided an absolute benefit in rectal sparing of 21.9-27.5%, 10.9-11.6%, and 5.1-5.4% at V50, V60, and V70, respectively. However, WP IMRT provided superior sparing of both bladder and rectum over each 4FBT plan. For the rectum, the advantage was around 10% at V70 and even greater at lower doses. Average NTCP values for Grade 2+ toxicity were 9.4-14.6% and 5.4% for 4FBT and WP IMRT, respectively. When examining the total number of plans that met rectal dose-volume objectives, 90% (86/96) met objectives with WP IMRT as compared to 48% (46/96) with 4FBT. Conclusion: Rectal shielding on the lateral fields of the 4FBT resulted in improvements in rectal dose points as compared to 4FBT with no rectal shielding. However, the improvements came at the expense of PLN PTV coverage. WP IMRT is, however, under each dosimetric endpoint investigated, superior to 4FBT and allows dose escalation to the prostate while respecting current dose objectives in the majority of patients. 946 poster Clinical results of patients with prostate cancer treated with intensitiy modulated radiotherapy
D. Boehmer ~, R. Herschel ~, J. Bohsung 2, L Eichwurzef, H. Badakhshi 1, V. Budach ~ ~Charite Campus Mitte, Dept. of Radiation Oncology, Berlin, Germany ;Charit~ Campus Mitte, Dept. of Radiation Oncology-Physics Dept., Berlin, Germany Methods and Material: Between September 2000 and September 2003 ninety-six patients with prostate cancer where treated with intensity modulated radiotherapy. Tlc, T2a, T2b, T2c and T3a tumours were found in 38, 27, 17, 2, and 11 patients, respectively. One patient presented with a suspicious T4 tumour (infiltration of bladder neck according to MRI). In most patients a Gleason Score of 2-6 (77.1%) was detected. 14 patients (14.6%) and 8 patients (8.3%) presented with a Gleason Score 7 and 8-10, respectively. Pretreatment PSA level < 10 ng/ml, 10-20 ng/ml and > 20 ng/ml where determined in 67, 25 and 4 patients. Mean RT dose was 79.8 Gy (range 74 Gy -82 Gy). The treatment technique for all patients consisted of an arrangement of 5 intensity modulated fields using the SIB technique (Simultaneous Integrated Boost) with dynamic Multi-LeafCollimators. Toxicity was evaluated using the Common Toxicity Criteria version 2.0. Results: Treatment was completed without interruption in all IMRT patients. For the first 20 patients we performed daily electronic portal imaging. The standard deviation o f the lateral, cranio-caudal and anterior-posterior set-up errors was 2.8, 2.2 and 1.9 mm, respectively. 95% of all treatments were within a + 5 mm margin from the isocentre. Throughout the treatment course of twenty patients with 1640 electronic portal images only 64 treatment sessions had to be interrupted to perform an on-line set-up correction. None of the patients experienced grade 4 acute side effects. Grade 3 side effects were rare with 1%, 2% and 1% of all patients experiencing painful urination, an increase of urinary frequency and diarrhea, respectively. The most frequent acute GU side effects were mild and moderate painful urination (44% and 11%), increased urinary frequency (34% and 10%) and nocturnal urination (47% and 7%). Mild and moderate GI acute side effects were rectal pain (27% and 3%), increase in stool frequency (36% and 2%), rectal
Posters
mucositis (34% and 4%) with blood-streaked stool in 14% of all patients. So far no late radiation toxicity grade 3 or 4 has been observed. Conclusion: IMRT of prostate cancer is feasible and results in a low rate of acute side effects. So far the rate of late radiation toxicity is low although the follow-up is still too short. The results of set-up deviation are in good agreement with the literature. 947 poster A prospective study of erectile dysfunction & its effect on quality of life after prostate brachytherapy
A. Henderson ~, P. Sooriakumaran ~, S.en.E.M LangleS, R.rt. W Laing 2 ~St.Luke's Cancer Center, Urology, Guildford, United Kingdom 2St.Luke's Cancer Center, Oncology, Guildford, United Kingdom Introduction: We assess the effect of brachytherapy on potency and quality of life in a prospective, patient administered questionnaire study. Patients and methods: Patients completed the International Index of Erectile Function (IIEF-5) prior to brachytherapy and at 6 weeks, 3,6,9,12,18 and 24 months post implant. Patients who considered that they had erectile problems completed the ED effect on Quality of Life (EDQol) questionnaire. Men with an IIEF-5 score of <12/25 (moderate-severe ED) were considered impotent. Result: 153 patients completed baseline and >1 postimplant IIEF-5 questionnaire, 39% (n=60) were potent pre-implant. 67% of potent patients maintained potency at last follow up (mean FU 15m). Potency rates improved over time postimplant 6wk-47%, 3m-56%, 6m-48%, 9m-63%, 12m56%, 18m-75%. Of 93 patients impotent at baseline 63% completed the EDQuol; 15% reported no effect on quality of life, 39% mild effect, 30% moderate effect and 16% a severe effect. In patients who were impotent as a result of treatment at the 6 month assessment 88% completed EDQuol; 7% had no effect on quality of life, 47% mild effect, 27% moderate effect and 20% a severe effect. Early potency after brachytherapy is encouraging and compares favourably with other modalities for the treatment of early prostate cancer. ED improves with time postbrachytherapy within the first 18 months. Patients experiencing impotence as a result of treatment are equally as likely to report moderate-severe ED effects on quality of life as those impotent before brachytherapy. 948 poster Use of gold markers for setup in fractionated HDR brachytherapy and organ tracking during iMRT in combined radiotherapy of prostate cancer
D.M. Aebersold, D. Vetterli 1, C. Kolotas 1, S. Thalmann 1, B. Isaak ~, G. Thalmann 2, L. Kemmerling ~, F. Behrensmeier 1, R. Mini I, R. Greiner 1 1University of Bern, Inselspital, Radiation Oncology, Bern, Switzerland 2University of Bern, Inselspital, Urology, Bern, Switzerland Objective:To investigate the use of gold markers for setup in combined radiotherapy of advanced prostate cancer. Material and Methods: 21 pts. with advanced prostate cancer were analysed who underwent combined HDR brachytherapy (BT; 3 x 7 Gy) and EBRT (IMRT, 50 Gy).