- Email: [email protected]
949 poster Results of hypofractioated IMRT in prostate cancer
Posters
During spinal anesthesia for the BT implant, 3 gold markers were inserted into the prostate, serving as intraprostatic reference to readjust the length position of the applicators prior to each BT fraction. The deviation of the applicator length positions were determined on radiographs. The same gold markers were subsequently used for organ tracking during IMRT, allowing to substantially decreasing the safety margin around the clinical target volume. DRRs (0 and 90 degrees) based on planning CT were used as reference image for daily patient setup. Before each treatment fraction orthogonal localization images were acquired using the aS500 (Varian Medical Systems) portal imager along with a novel dose saving acquisition mode (RadMode) allowing to take high quality images with 1 MU per image only. By matching the actual marker positions to the DRRs, the translational devations could be calculated, and the patients position was changed accordingly. Results: The length position of applicators varied substantially between BT fractions (average - 4 m m [range 16 mm to 3 mm] at fraction 2; average 1 mm [range -10 to 7 mm] at fraction 3. However, the original position of the applicators could be easily readjusted prior to each fraction. The marker positions were stable during BT and EBRT, one marker got lost during EBRT, without compromising the online setup procedure for patient repositionning. To estimate the intrafraction prostate movement during the course of the treatment, we analyzed images taken during the application of field 1 (start of treatment fraction) and field 5 (end of treatment fraction). The mean displacements for field 1 were - 0.6 mm (SD 1.5) in the lateral and 0.5 mm (SD 1.8) in the cracio-caudal direction. In field 5, the mean displacements were as follows: 0.4 mm (SD 2.2) in the anterio-posterior and - 0.1 (SD 2.0) in the cranio-caudal direction. In one patient, organ tracking was impossible due to excessive intra-fraction prostate movement. ConcluSion: Gold markers represent a valuable tool to ensure setup accuracy in combined radiotherapy of advanced prostate cancer. 949 poster Results of hypofractioated IMRT in prostate cancer
I. Syndikus Clatterbridge Centre for Oncolegy, Radiotherapy, Bebington, United Kingdom Bakcground: Hypofractionated, dose escalated IMRT with an integrated boost technique improves tumour control without increasing toxicity. Methods: patients with intermediate risk prostate cancer were treated with 3-6 months of adjuvant hormone therapy. Patients were scanned using the Philips Acsim TM CT scanner and planned on a Plato computer with Nucletron's inverse planning module. The high dose PTV2 (prostate and base of SV with no margin) received 70 Gy in 32 #, the PTV1 (prostate, SV and 1 cm margin) 64 Gy in 32#. These dose level give similar TCP, EUD and NTCP's compared to the tandard regimen (74 Gy/37#). Results: It was possible to produce an acceptable plan for all patients. A dose volume spreadsheet for rectum, bladder and PTV coverage was developed. This improved and simplified the evaluation of possible plan solutions. Acute toxicity was moderate and obstructive urinary symptoms were the main problem. 6 patients had grade 2 and 6 patients grade 3 toxicity, 10 needed alpha blocker. Rectal toxicity was minor, 10 patients had grade1 toxicity. There was one patient with temporary late grade 3 diarrhoea which resolved spontaneously. No other severe late toxicity was observed.
S401
Median
Range
Age Gleason score PSA (ng/ml)
64.8
57-72
6.5 20,9
Follow up T1 cNOM0
20 2 12
4-9 4.3-38 16-32
T2a-cNOM0 T3aNOM0
8
Conclusion: IMRT allows dose escalation without increased toxicity and hospital visits.
950 poster A comparison of acute toxicity of the prostate cancer patients treated with high dose rate and low dose rate interstitial brachytherapy
S. Shah., W. Fisher, P. Gilson, A. Korba, A. Razek, B. Romick, W. Samm, P. SiamL B. Smith, A. Sorensen Tri-State Prostate Cancer Center, Evansville Cancer Center, Evansville, IN, U.S.A. In the U.S.A. HDR prostate Brachytherapy is typically performed by delivering multiple fractions with a single insertion requiring hospitalization. We have developed an "out-patient" procedure utilizing two insertions and two fractions delivered about two weeks apart. Selection criteria is (TI,2 No) disease and patient being fully informed of alternative approaches including surgery. This procedure is team based including, urologists, radiation oncologists, physicists, anesthesiologists and nursing staff. The TRUS guided placement of needle applicators is performed under spinal anesthesia. Two fractions (2 weeks apart) are delivered 4 weeks after completion of external beam therapy (4500 - 5040 cGy) using either 3D conformal or IMRT. CT based isodose planning is carried out using ABACUS algorithm with 1000 cGy to encompass at least 90% of PTV (capsule + 0-2mm margin), 1200 cGy to the peripherial zones with localized hot spots restricted within the CTV. The dose to the rectum and urethra is maintained to be less than 1000 cGy and 1200 cGy respectively. One hundred forty-five patients were treated between January 2001 and December 2003. No severe genitourinary or gastrointestinal radiation side effects were experienced. Preliminary results indicate that these effects were reduced when compared to a group of 326 patients treated between 1999 - 2003 with LDR brachytherapy (I-125 and Pd-103 seeds). Long term followup is required to document cancer control. Our experience demonstrates that HDR brachytherapy can be performed effectively as an outpatient procedure tolerated very well by patients. 951 poster Prostate cancer and brachytherapy: a woman's issue?
J. Shafet~,K. Jansen, M. Gurel, B. Moran Chicago Prostate Cancer Center, Radiation Oncology, Westmont, IL, U.S.A. Introduction: This study provides a unique perspective on influences and concerns regarding the prostate cancer treatment decision-making process in a large number of female spouses/life partners of patients undergoing transperineal permanent prostate brachytherapy (PB). Methods and Materials: 3172 patients underwent PB between October 1997 and October 2002 at a single institution. In February 2002, 900 patients were randomly
During spinal anesthesia for the BT implant, 3 gold markers were inserted into the prostate, serving as intraprostatic reference to readjust the length position of the applicators prior to each BT fraction. The deviation of the applicator length positions were determined on radiographs. The same gold markers were subsequently used for organ tracking during IMRT, allowing to substantially decreasing the safety margin around the clinical target volume. DRRs (0 and 90 degrees) based on planning CT were used as reference image for daily patient setup. Before each treatment fraction orthogonal localization images were acquired using the aS500 (Varian Medical Systems) portal imager along with a novel dose saving acquisition mode (RadMode) allowing to take high quality images with 1 MU per image only. By matching the actual marker positions to the DRRs, the translational devations could be calculated, and the patients position was changed accordingly. Results: The length position of applicators varied substantially between BT fractions (average - 4 m m [range 16 mm to 3 mm] at fraction 2; average 1 mm [range -10 to 7 mm] at fraction 3. However, the original position of the applicators could be easily readjusted prior to each fraction. The marker positions were stable during BT and EBRT, one marker got lost during EBRT, without compromising the online setup procedure for patient repositionning. To estimate the intrafraction prostate movement during the course of the treatment, we analyzed images taken during the application of field 1 (start of treatment fraction) and field 5 (end of treatment fraction). The mean displacements for field 1 were - 0.6 mm (SD 1.5) in the lateral and 0.5 mm (SD 1.8) in the cracio-caudal direction. In field 5, the mean displacements were as follows: 0.4 mm (SD 2.2) in the anterio-posterior and - 0.1 (SD 2.0) in the cranio-caudal direction. In one patient, organ tracking was impossible due to excessive intra-fraction prostate movement. ConcluSion: Gold markers represent a valuable tool to ensure setup accuracy in combined radiotherapy of advanced prostate cancer. 949 poster Results of hypofractioated IMRT in prostate cancer
I. Syndikus Clatterbridge Centre for Oncolegy, Radiotherapy, Bebington, United Kingdom Bakcground: Hypofractionated, dose escalated IMRT with an integrated boost technique improves tumour control without increasing toxicity. Methods: patients with intermediate risk prostate cancer were treated with 3-6 months of adjuvant hormone therapy. Patients were scanned using the Philips Acsim TM CT scanner and planned on a Plato computer with Nucletron's inverse planning module. The high dose PTV2 (prostate and base of SV with no margin) received 70 Gy in 32 #, the PTV1 (prostate, SV and 1 cm margin) 64 Gy in 32#. These dose level give similar TCP, EUD and NTCP's compared to the tandard regimen (74 Gy/37#). Results: It was possible to produce an acceptable plan for all patients. A dose volume spreadsheet for rectum, bladder and PTV coverage was developed. This improved and simplified the evaluation of possible plan solutions. Acute toxicity was moderate and obstructive urinary symptoms were the main problem. 6 patients had grade 2 and 6 patients grade 3 toxicity, 10 needed alpha blocker. Rectal toxicity was minor, 10 patients had grade1 toxicity. There was one patient with temporary late grade 3 diarrhoea which resolved spontaneously. No other severe late toxicity was observed.
S401
Median
Range
Age Gleason score PSA (ng/ml)
64.8
57-72
6.5 20,9
Follow up T1 cNOM0
20 2 12
4-9 4.3-38 16-32
T2a-cNOM0 T3aNOM0
8
Conclusion: IMRT allows dose escalation without increased toxicity and hospital visits.
950 poster A comparison of acute toxicity of the prostate cancer patients treated with high dose rate and low dose rate interstitial brachytherapy
S. Shah., W. Fisher, P. Gilson, A. Korba, A. Razek, B. Romick, W. Samm, P. SiamL B. Smith, A. Sorensen Tri-State Prostate Cancer Center, Evansville Cancer Center, Evansville, IN, U.S.A. In the U.S.A. HDR prostate Brachytherapy is typically performed by delivering multiple fractions with a single insertion requiring hospitalization. We have developed an "out-patient" procedure utilizing two insertions and two fractions delivered about two weeks apart. Selection criteria is (TI,2 No) disease and patient being fully informed of alternative approaches including surgery. This procedure is team based including, urologists, radiation oncologists, physicists, anesthesiologists and nursing staff. The TRUS guided placement of needle applicators is performed under spinal anesthesia. Two fractions (2 weeks apart) are delivered 4 weeks after completion of external beam therapy (4500 - 5040 cGy) using either 3D conformal or IMRT. CT based isodose planning is carried out using ABACUS algorithm with 1000 cGy to encompass at least 90% of PTV (capsule + 0-2mm margin), 1200 cGy to the peripherial zones with localized hot spots restricted within the CTV. The dose to the rectum and urethra is maintained to be less than 1000 cGy and 1200 cGy respectively. One hundred forty-five patients were treated between January 2001 and December 2003. No severe genitourinary or gastrointestinal radiation side effects were experienced. Preliminary results indicate that these effects were reduced when compared to a group of 326 patients treated between 1999 - 2003 with LDR brachytherapy (I-125 and Pd-103 seeds). Long term followup is required to document cancer control. Our experience demonstrates that HDR brachytherapy can be performed effectively as an outpatient procedure tolerated very well by patients. 951 poster Prostate cancer and brachytherapy: a woman's issue?
J. Shafet~,K. Jansen, M. Gurel, B. Moran Chicago Prostate Cancer Center, Radiation Oncology, Westmont, IL, U.S.A. Introduction: This study provides a unique perspective on influences and concerns regarding the prostate cancer treatment decision-making process in a large number of female spouses/life partners of patients undergoing transperineal permanent prostate brachytherapy (PB). Methods and Materials: 3172 patients underwent PB between October 1997 and October 2002 at a single institution. In February 2002, 900 patients were randomly