BACKGROUND: We have implemented an intensity-modulated radiotherapy (IMRT) protocol for simultaneous irradiation of bladder and lymph nodes. In this report, doses to normal tissue from IMRT and our previous conformal sequential boost technique are compared. MATERIAL AND METHODS: Sixteen patients with urinary bladder cancer were treated using a six-field dynamic IMRT beam arrangement delivering 60 Gy to the bladder and 48 Gy to the pelvic lymph nodes. Dose-volume histogram (DVH) parameters for relevant normal tissues (bowel, bowel cavity, rectum and femoral heads) for the IMRT plans were compared with corresponding DVHs from our previous conformal sequential boost technique. Calculations of the generalized Equivalent Uniform Dose (gEUD) were performed for the bowel, with a reference volume of 200 cm(3) and a volume effect parameter k = 4, as well as for the rectum, using k = 12. Acute gastrointestinal (GI) and genitourinary (GU) RTOG toxicity was recorded. RESULTS: Statistical significant normal tissue sparing was obtained by IMRT. For the bowel, a significant reduction was obtained at all dose levels between 20 and 50 Gy (p < 0.05), e.g. from 180 to 121 cm(3) at 50 Gy, while the gEUD was reduced from 58 to 53 Gy (p < 0.05). Similar patterns were seen for the bowel cavity. For the rectum, IMRT reduced the maximum dose as well as the volumes receiving more than 50 and 60 Gy (p < 0.05), e.g. from 72 to 48 cm(3) at 50 Gy. The rectum gEUD was reduced from 55 to 53 Gy (p < 0.05). For the femoral heads, IMRT reduced the maximum dose as well as the volumes above all dose levels. The rate of acute peak Grade 2 GI RTOG complications was 38% after IMRT. CONCLUSION: IMRT to the urinary bladder and elective lymph nodes result in considerable normal tissue sparing compared to conformal sequential boost technique. This has paved the way for further studies combining IMRT with image-guided radiotherapy (IGRT) in bladder cancer.
BACKGROUND: We have implemented an intensity-modulated radiotherapy (IMRT) protocol for simultaneous irradiation of bladder and lymph nodes. In this report, doses to normal tissue from IMRT and our previous conformal sequential boost technique are compared. MATERIAL AND METHODS: Sixteen patients with urinary bladder cancer were treated using a six-field dynamic IMRT beam arrangement delivering 60 Gy to the bladder and 48 Gy to the pelvic lymph nodes. Dose-volume histogram (DVH) parameters for relevant normal tissues (bowel, bowel cavity, rectum and femoral heads) for the IMRT plans were compared with corresponding DVHs from our previous conformal sequential boost technique. Calculations of the generalized Equivalent Uniform Dose (gEUD) were performed for the bowel, with a reference volume of 200 cm(3) and a volume effect parameter k = 4, as well as for the rectum, using k = 12. Acute gastrointestinal (GI) and genitourinary (GU) RTOG toxicity was recorded. RESULTS: Statistical significant normal tissue sparing was obtained by IMRT. For the bowel, a significant reduction was obtained at all dose levels between 20 and 50 Gy (p < 0.05), e.g. from 180 to 121 cm(3) at 50 Gy, while the gEUD was reduced from 58 to 53 Gy (p < 0.05). Similar patterns were seen for the bowel cavity. For the rectum, IMRT reduced the maximum dose as well as the volumes receiving more than 50 and 60 Gy (p < 0.05), e.g. from 72 to 48 cm(3) at 50 Gy. The rectum gEUD was reduced from 55 to 53 Gy (p < 0.05). For the femoral heads, IMRT reduced the maximum dose as well as the volumes above all dose levels. The rate of acute peak Grade 2 GI RTOG complications was 38% after IMRT. CONCLUSION: IMRT to the urinary bladder and elective lymph nodes result in considerable normal tissue sparing compared to conformal sequential boost technique. This has paved the way for further studies combining IMRT with image-guided radiotherapy (IGRT) in bladder cancer.
Authors: Patricia Moretto; Lori Wood; Urban Emmenegger; Normand Blais; Som Dave Mukherjee; Eric Winquist; Eric Charles Belanger; Robert Macrae; Alexander Balogh; Ilias Cagiannos; Wassim Kassouf; Peter Black; Piotr Czaykowski; Joel Gingerich; Scott North; Scott Ernst; Suzanne Richter; Srikala Sridhar; M Neil Reaume; Denis Soulieres; Andrea Eisen; Christina M Canil Journal: Can Urol Assoc J Date: 2013 Jan-Feb Impact factor: 1.862
Authors: Morten Høyer; Maria Thor; Sara Thörnqvist; Jimmi Søndergaard; Yasmin Lassen-Ramshad; Ludvig Paul Muren Journal: Cancer Imaging Date: 2011-10-03 Impact factor: 3.909
Authors: Malgorzata A Bill; Kirtiman Srivastava; Conor Breen; Karl T Butterworth; Stephen J McMahon; Kevin M Prise; Karen D McCloskey Journal: Oncotarget Date: 2017-10-24