Trends in Medical Research1819-35872151-6065Science International10.3923/tmr.2006.55.65MangarStephen CoffeyJerome McNairHelen HansenVibeke N.SohaibSyed HuddartRobert ParkerChristopher HorwichAlan DearnaleyDavid 1200611Prostate motion during radiotherapy is influenced mainly by both bladder and rectal filling. This study assesses the impact of bladder and rectal changes on prostate movement and determines whether there are any predictive factors for prostate motion from the initial radiotherapy planning scan. Twenty six patients undergoing conformal radiotherapy for prostate cancer had two CT scans approximately 35 min apart whilst remaining in the same radiotherapy planning position. Prostate, bladder and rectal contours were outlined on both CTs and prostate movement with respect to the bony pelvis was calculated after fusion of CT data sets. This method for determining prostate movement was validated by fiducial markers placed in 6 patients. Cross sectional and volumetric bladder and rectal data were analysed from each scan and correlated with prostate movement. Considerable intra-patient variations in bladder and rectal volumes occurred over a 35 min interval. There were no predictive bladder, or rectal parameters on initial CT to predict for prostate motion, with poor correlations observed between A-P prostate movement and the initial rectal volume (r = -0.19), cross sectional area (r = 0.17) and A-P diameter (r = -0.21), and only weak positive correlations between S-I prostate movement and both initial rectal volume (r = 0.43, p = 0.03) and A-P diameter (r = 0.44, p = 0.02). However the changes between the initial and final rectal cross sectional area (r = 0.82, p<0.001) and AP diameter (r = 0.81, p<0.001) were more closely related to A-P prostate movement. These findings confirm the principal that as the rectum expands it moves the prostate anteriorly, whilst changes in bladder volume seems to contribute less to inferior prostate motion. Strategies to manage these movements include adapting the posterior margin to the degree of rectal filling, or using methods to empty the rectum prior to treatment.]]>Antolak, J.A., II. Rosen, C.H. Childress G.K. Zagars and A. Pollack,199842661672Artigan, X., H.P. Monique, M.D. Smitsmans, J.V. Lebesque and H. Bartelink200459595601Balter, J.M., H.M. Sandler, K. Lam, R.L. Bree and A.S. Lichter et al.,199531113118Beard, C., P. Kijewski, M. Bussiere, R. Gelman and D. Gladstone et al.,199634451458Coffey, J., H. McNair and B. Shoulders et al.,200473S288289Crook, J.M., Y. Raymond and D. Salhani et al.,1995373542Dehnad, H., A.J. Nederveen, U.A. van der Heide van, R.J. Moorselaar, P. Hofman and J.J. Lagendijk200367295302Hanley, J., M.A. Lumley, G.S. Mageras, J. Sun and M.J. Zelefsky et al.,199737435444Herman, M.G., T.M. Pisansky, J.I. Kruse, I. Prisciandaro Joann, J. Davis Brian and F. King Bernard,20035711311140Langen, K.M., J. Pouliot, R.T.T. Anezinos, M. Aubin and A.R. Gottschalk et al.,200357635644Langen, K.M., Y. Zhang, D. Andrews Rhonda, E. Hurley Monica and L. Meeks Sanford et al.,20056215171524Lattanzi, J., S. McNeeley, W. Pinover E. Horwitz and I. Das et al.,199943719725Litzenberg, L.A., L.A. Dawson, H. Sandler D.L. McShan and R.K. Ten Haken et al.,200252699703McGary, J., B. The and W. Grant,20012001McNair, H.A., U.N. ODoherty and A.R. Norman et al.,20052005Melian, E., G.S. Mageras, Z. Fuks, S.A. Leibel and A. Niehaus et al.,1997387381Mohan, D.S., P.A. Kupelian and T.R. Willoughby,200046575580Padhani, A.R., V.S. Khoo, J. Suckling, J.E. Husband and M.O. Leach et al.,199944525533Patel, R.R., N. Orton and W. Tome, C. Rick and A.R. Mark,200367285294Pickett, B., M.III. Roach, L. Verhey, P. Horine and C. Malfatti et al.,199532211218Roach, M.III., P. Falliace-Akazawa and C. Malfatti,19975187194Roeske, J., J. Forman, C. Mesina, T. He and C.A. Pelizzari et al.,19953313211329Rudat, V., P. Schraube, D. Oetzel, D. Zierhut and M. Flentje et al.,19963510271034Schild, S.E., H.E. Casale and L.P. Bellefontaine,1993181315South, C., C. Clark and A. Norman et al.,2005Stroom, J.C., P.C.M. Koper, G.A. Korevaar, M. Van os and M. Janssen et al.,199951237248Ten-Haken, R.K., J.D. Forman, D.K. Heimburger, A. Gerhardsson and D.L. Mcshan et al.,19912013171324Tinger, A., J.M. Michalski, A. Cheng D.A. Low and R. Zhu et al., 199842213221Tinger, A., J.M. Michalski, W.R. Bosch, R.K. Valicenti, D.A. Low and R.J. Myerson,199634683690van Herk, M.,2004145264van Herk, M., A. Bruce, A. Kroes, T. Shouman, A. Touw and J.V. Lebesque,19953313111320Van Lin, E.N.J.T., L.P. van der Vight, J.A. Witjes, H.J. Huisman, J.W.H. Leer and A.G. Visser, 200561278288Vigneault, E., J. Pouliot and J. Laverdiere et al.,199737205212Verhey, L.J.,19955100114Zelefsky, M.J., D. Crean, G.S. Mageras, O. Lyass and L. Happersett et al.,199950225234