Dose conversion coefficients for electron exposure of the human eye lens

Transcription

1 Physics in Medicine & Biology CORRIGENDUM Dose conversion coefficients for electron exposure of the human eye lens To cite this article: R Behrens et al 2010 Phys. Med. Biol View the article online for updates and enhancements. Related content - Dose conversion coefficients for electron exposure of the human eye lens R Behrens, G Dietze and M Zankl - Dose conversion coefficients for photon exposure of the human eye lens R Behrens and G Dietze - Dose conversion coefficients for monoenergetic electrons incident on a realistic human eye model P Nogueira, M Zankl, H Schlattl et al. Recent citations - Monte Carlo study of the scattered radiation field near the eyes of the operator in interventional procedures Paolo Ferrari et al - DOSE CONVERSION COEFFICIENTS FOR ELECTRON EXPOSURE OF THE HUMAN EYE LENS: CALCULATIONS INCLUDING A WHOLE BODY PHANTOM R. Behrens - Dose conversion coefficients for monoenergetic electrons incident on a realistic human eye model with different lens cell populations P Nogueira et al This content was downloaded from IP address on 30/12/2017 at 06:27

2 IOP PUBLISHING Phys. Med. Biol. 55 (2010) PHYSICS IN MEDICINE AND BIOLOGY doi: / /55/13/c01 Corrigendum Dose conversion coefficients for electron exposure of the human eye lens R Behrens, G Dietze and M Zankl 2009 Phys. Med. Biol Due to two errors in the geometry module of the EGSnrc C++ class library egs++ (EGSpp), several data presented in the original work are not correct. The following figures and tables present the correct values of the dose conversion coefficients for electron exposure of the human eye lens. The corrected values deviate at most by about 25% and 50% for 0 and 45 angles of incidence, respectively, from the ones presented originally. The conclusions given in sections 4 and 5 of the original paper are, however, still valid. Nevertheless, the text has to be slightly modified: the last sentence in the abstract must be changed to Compared to the values adopted in 1996 by the International Commission on Radiological Protection (ICRP) the new values are up to times smaller for electron energies below 1 MeV, nearly equal at 1 MeV and above 2 MeV, and by a factor of 1.3 larger at about 1.5 MeV electron energy. In section 3.2, line one, the words near 2 MeV must be changed to below 2 MeV. In the same section, third bullet point, line five, the words from side to top to bottom must be changed to from side to bottom to top. In section 3.3, line five, the words a significant impact must be changed to no significant impact ; the rest of that sentence must be deleted. The first error in EGS++ was corrected by Ernesto Mainegra from the National Research Council of Canada (NRC). A short description of what has to be done to remove the error is given as follows. Inthefile %HEN HOUSE%/egs++/geometry/egs genvelope/egs envelope geometry.h the two lines 377 and 685 have to be changed from int I = geometries[j]->iswhere(x); to int i = geometries[j]->iswhere(x+u t); that means +u t has to be added. In Windows the two files egs genvelope.dll and egs envelope geometry.o in the directory %HEN HOUSE%/egs++/dso/%my machine% have to be deleted. In Linux the two filenames are libegs genvelope.so and egs envelope geometry.o. To recompile the library make has to be run either from the directory %HEN HOUSE%/egs++/geometry/egs genvelope/ or from %HEN HOUSE%/ egs++/. User codes do not need to be recompiled as the new libraries are loaded during the subsequent runs. The second error is a round-off problem. Due to this error users should avoid surfaces that lie on each other inside a composite geometry (for example, in a union or in an envelope /10/ $ Institute of Physics and Engineering in Medicine Printed in the UK 3937

3 3938 Corrigendum geometry). If the geometry definition requires such a case, it is recommended to let the surfaces deviate a little (for example 1 μm or a tens of it, in any case small enough to be considered negligible). The errors are present at least until version of EGSnrc. Details will be presented in a future Letter to the Editor. Finally, two internet references have changed. The new ones are given below. Acknowledgment (added) The authors wish to thank Ernesto Mainegra (NRC) for removing the error in EGSpp and for giving several helpful hints and comments. References (corrected) Kawrakow I 2005 egspp: the EGSnrc C++ class library NRCC Report PIRS-899, available at software/egsnrc/documentation/pirs898/index.html Kawrakow I and Rogers D W O 2006 The EGSnrc Code System: Monte Carlo Simulation of Electron and Photon Transport NRCC Report PIRS-701, available at documentation/pirs701/index.html Figure 4. Mean absorbed dose per incident electron fluence for normal incidence (0 ) for different parts of the lens (this work) and for the entire lens (other works).

4 Corrigendum 3939 Figure 5. Mean absorbed dose per incident electron fluence for normal incidence (0 ) for different parts of the lens using the mathematical model and for the entire lens using the voxel models. Figure 6. Mean absorbed dose per incident electron fluence for the sensitive volume of the lens (cells at risk) for normal radiation incidence and for other angles (radiation coming from the side). The points are connected using splines.

5 3940 Corrigendum (a) (b) (c) Figure 7. (a) Mean absorbed dose per incident electron fluence for the sensitive volume of the lens and conversion coefficient H p (3; )/ for different angles of radiation incidence: (a) 15, (b) 30,(c)45. The points are connected using splines.

6 Corrigendum 3941 Figure 8. Mean absorbed dose per incident electron fluence for normal radiation incidence (0 angle of incidence) for the sensitive part of the lens with different volumes (which are indicated in the sketch of the lens in the left part of the figure), for the entire lens, and for the conversion coefficient H p (3;0 )/. The points are connected using splines. Figure 9. Conversion coefficients for the operational quantities (taken from ICRU (1998)) and dose per fluence for the eye lens (this work) for normal incidence (0).

7 3942 Corrigendum Table A1. Mean absorbed dose per electron fluence for the sensitive volume of the lens, D s /, for the insensitive volume of the lens, D i /, and for the entire lens of the eye, D e /, for monoenergetic electrons incident in the AP geometry on a mathematical model of the eye. The values in brackets are the statistical one sigma standard uncertainties. The overall uncertainty is the geometrical sum of the statistical uncertainty and the non-statistical uncertainty which is estimated to be 2.5%, see section 2.5. Mean absorbed dose per electron fluence (pgy cm 2 )for the Electron sensitive insensitive entire lens, energy (MeV) volume, D s / volume, D i / D e / (8) (3) (3) (10) (4) (4) (13) (5) (5) (20) (8) (7) (3) (10) (10) (3) (1) (1) (2) (2) (4) (2) (1) (3) (2) 2.56 (2) 9.97 (3) (3) (4) 32.3 (1) (4) 36.4 (1) 69.1 (1) (2) 151 (1) 191 (1) (2) 280 (1) 307 (1) (2) 369 (1) 381 (1) (2) 411 (1) 414 (1) (1) 406 (1) 402 (1) (1) 378 (1) 373 (1) (1) 352 (1) 348 (1) (1) 335 (1) 332 (1) (1) 316 (1) 314 (1) (1) 308 (1) 306 (1) (1) 307 (1) 305 (1) (1) 304 (1) 302 (1) (1) 303 (1) 301 (1) (1) 303 (1) 301 (1)

8 Table A2. Mean absorbed dose per electron fluence for the sensitive volume of the lens, D s /, for the insensitive volume of the lens, D i /, and for the entire lens of the eye, D e /,for mono-energetic electrons incident at an angle of incidence of 15 on a mathematical model of the eye. The values in brackets are the statistical one sigma standard uncertainties. The overall uncertainty is the geometrical sum of the statistical uncertainty and the non-statistical uncertainty which is estimated to be 2.5%, see section 2.5. Mean absorbed dose per electron fluence (pgy cm 2 )forthe Electron sensitive volume, D s / insensitive volume, D i / entire lens, D e / energy Radiation incidence at 15 from Radiation incidence at 15 from Radiation incidence at 15 from (MeV) the side the bottom the top the side the bottom the top the side the bottom the top (8) (8) (8) (3) (3) (3) (3) (3) (3) (11) (11) (11) (4) (4) (4) (4) (4) (4) (13) (13) (13) (5) (5) (5) (5) (5) (5) (19) (19) (18) (8) (8) (8) (7) (7) (7) (3) (3) (3) (11) (1) (11) (10) (9) (10) (3) (3) (3) (1) (1) (1) (1) (1) (1) (3) (2) (2) (2) (2) (2) (5) (4) (4) (2) 7.04 (2) 7.13 (2) (1) (1) (1) (4) (3) (3) (2) 42.5 (2) 42.3 (2) 2.84 (2) 2.32 (2) 2.39 (2) (3) 9.20 (3) 9.23 (3) (3) (3) (3) (5) 11.3 (0) (4) 31.7 (1) 29.7 (1) 29.5 (1) (4) (4) (4) 36.0 (1) 33.0 (1) 33.1 (1) 66.8 (1) 63.1 (1) 63.1 (1) (2) 357 (2) 356 (2) 144 (1) 137 (1) 137 (1) 182 (1) 175 (1) 175 (1) (2) 418 (2) 413 (2) 268 (1) 261 (1) 258 (1) 295 (1) 288 (1) 285 (1) (2) 431 (2) 424 (2) 359 (1) 353 (1) 347 (1) 371 (1) 366 (1) 360 (1) (2) 419 (2) 414 (2) 406 (1) 395 (1) 391 (1) 408 (1) 399 (1) 395 (1) (2) 381 (2) 376 (2) 405 (1) 402 (1) 397 (1) 401 (1) 398 (1) 393 (1) (1) 351 (1) 351 (1) 381 (1) 382 (1) 378 (1) 375 (1) 376 (1) 374 (1) (1) 330 (1) 333 (1) 353 (1) 356 (1) 358 (1) 349 (1) 352 (1) 354 (1) (1) 320 (1) 319 (1) 336 (1) 341 (1) 341 (1) 332 (1) 337 (1) 337 (1) (1) 304 (1) 306 (1) 319 (1) 322 (1) 322 (1) 316 (1) 319 (1) 319 (1) (1) 298 (1) 298 (1) 310 (1) 313 (1) 313 (1) 308 (1) 310 (1) 311 (1) (1) 295 (1) 295 (1) 306 (1) 309 (1) 309 (1) 303 (1) 307 (1) 307 (1) (1) 291 (1) 293 (1) 303 (1) 305 (1) 306 (1) 302 (1) 302 (1) 304 (1) (1) 291 (1) 292 (1) 303 (1) 304 (1) 306 (1) 301 (1) 302 (1) 303 (1) (1) 292 (1) 291 (1) 302 (1) 305 (1) 303 (1) 300 (1) 303 (1) 301 (1) Corrigendum 3943

9 Table A3. Mean absorbed dose per electron fluence for the sensitive volume of the lens, D s /, for the insensitive volume of the lens, D i /, and for the entire lens of the eye, D e /,for mono-energetic electrons incident at an angle of incidence of 30 on a mathematical model of the eye. The values in brackets are the statistical one sigma standard uncertainties. The overall uncertainty is the geometrical sum of the statistical uncertainty and the non-statistical uncertainty which is estimated to be 2.5%, see section 2.5. Mean absorbed dose per electron fluence (pgy cm 2 )forthe Electron sensitive volume, D s / insensitive volume, D i / entire lens, D e / energy Radiation incidence at 30 from Radiation incidence at 30 from Radiation incidence at 30 from (MeV) the side the bottom the top the side the bottom the top the side the bottom the top (8) (7) (8) (3) (3) (3) (3) (3) (3) (10) (10) (10) (4) (4) (4) (4) (4) (4) (13) (14) (13) (5) (5) (5) (5) (5) (5) (17) (17) (18) (8) (7) (7) (7) (7) (7) (2) (2) (2) (10) (11) (10) (9) (10) (9) (3) (3) (3) (13) (13) (13) (1) (1) (1) (3) (2) (2) (2) (2) (2) (6) (4) (4) (2) 5.57 (2) 5.21 (2) (2) (1) (1) (4) (3) (3) (2) 33.2 (1) 31.2 (1) 3.12 (2) 1.70 (1) 1.67 (1) (3) 7.09 (3) 6.73 (3) (3) 90.8 (3) 86.8 (2) (5) 8.32 (4) 7.95 (4) 29.5 (1) 22.4 (1) 21.4 (1) (4) (3) (3) 33.2 (1) 24.5 (1) 23.5 (1) 59.7 (1) 47.8 (1) 46.0 (1) (2) 289 (2) 278 (2) 129 (1) 104 (1) 101 (1) 163 (1) 136 (1) 131 (1) (2) 357 (2) 345 (2) 240 (1) 206 (1) 199 (1) 266 (1) 232 (1) 224 (1) (2) 386 (2) 371 (2) 332 (1) 293 (1) 281 (1) 345 (1) 309 (1) 296 (1) (2) 391 (2) 379 (2) 386 (1) 341 (1) 331 (1) 390 (1) 349 (1) 339 (1) (2) 379 (2) 369 (2) 406 (1) 377 (1) 365 (1) 402 (1) 377 (1) 366 (1) (2) 361 (2) 351 (2) 391 (1) 377 (1) 366 (1) 386 (1) 374 (1) 364 (1) (1) 343 (1) 334 (1) 368 (1) 364 (1) 351 (1) 363 (1) 361 (1) 348 (1) (1) 327 (1) 320 (1) 344 (1) 348 (1) 339 (1) 341 (1) 344 (1) 336 (1) (1) 312 (1) 304 (1) 324 (1) 330 (1) 320 (1) 321 (1) 327 (1) 317 (1) (1) 303 (1) 294 (1) 313 (1) 319 (1) 308 (1) 311 (1) 316 (1) 306 (1) (1) 298 (1) 292 (1) 309 (1) 313 (1) 304 (1) 307 (1) 310 (1) 302 (1) (1) 294 (1) 288 (1) 308 (1) 309 (1) 300 (1) 306 (1) 307 (1) 298 (1) (1) 294 (1) 289 (1) 305 (1) 307 (1) 299 (1) 303 (1) 305 (1) 297 (1) (1) 295 (1) 287 (1) 305 (1) 308 (1) 297 (1) 303 (1) 305 (1) 295 (1) 3944 Corrigendum

10 Table A4. Mean absorbed dose per electron fluence for the sensitive volume of the lens, D s /, for the insensitive volume of the lens, D i /, and for the entire lens of the eye, D e /,for mono-energetic electrons incident at an angle of incidence of 45 on a mathematical model of the eye. The values in brackets are the statistical one sigma standard uncertainties. The overall uncertainty is the geometrical sum of the statistical uncertainty and the non-statistical uncertainty which is estimated to be 2.5%, see section 2.5. Mean absorbed dose per electron fluence (pgy cm 2 )forthe Electron sensitive volume, D s / insensitive volume, D i / entire lens, D e / energy Radiation incidence at 45 from Radiation incidence at 45 from Radiation incidence at 45 from (MeV) the side the bottom the top the side the bottom the top the side the bottom the top (7) (6) (7) (3) (3) (3) (3) (2) (3) (10) (9) (10) (4) (4) (4) (3) (3) (4) (12) (11) (11) (5) (5) (5) (5) (4) (4) (17) (16) (16) (7) (7) (7) (7) (6) (6) (2) (21) (2) (10) (9) (9) (9) (8) (8) (3) (3) (3) (13) (12) (11) (12) (11) (11) (3) (12) (12) (16) (1) (2) (6) (2) (2) (2) 2.62 (1) 2.12 ( 1) (1) (6) (6) (4) (2) (2) (2) 17.0 (1) 14.0 (1) 2.82 (2) (10) (9) 9.01 (3) 3.54 (2) 2.93 (2) (3) 49.1 (2) 42.4 (2) (4) 3.96 (2) 3.35 (2) 24.5 (1) (4) (3) (3) 91.8 (3) 80.8 (2) 27.5 (1) (5) (4) 48.1 (1) 26.0 (1) 22.6 (1) (1) 181 (1) 167 (1) 103 (1) 58.9 (4) 52.3 (4) 130 (1) 79.7 (4) 71.9 (4) (2) 246 (1) 229 (1) 197 (1) 125 (1) 114 (1) 220 (1) 146 (1) 134 (1) (2) 294 (2) 272 (2) 281 (1) 194 (1) 178 (1) 295 (1) 211 (1) 194 (1) (2) 318 (2) 293 (2) 340 (1) 247 (1) 226 (1) 348 (1) 259 (1) 238 (1) (2) 342 (2) 315 (2) 388 (1) 308 (1) 283 (1) 388 (1) 314 (1) 288 (1) (2) 346 (2) 324 (2) 397 (1) 334 (1) 310 (1) 392 (1) 336 (1) 312 (1) (2) 341 (2) 315 (2) 387 (1) 340 (1) 312 (1) 382 (1) 340 (1) 312 (1) (2) 329 (2) 309 (2) 367 (1) 333 (1) 309 (1) 363 (1) 332 (1) 309 (1) (1) 308 (1) 285 (1) 339 (1) 316 (1) 288 (1) 336 (1) 315 (1) 288 (1) (1) 296 (1) 274 (1) 325 (1) 304 (1) 276 (1) 322 (1) 303 (1) 276 (1) (1) 289 (1) 271 (1) 314 (1) 295 (1) 271 (1) 312 (1) 294 (1) 271 (1) (1) 285 (1) 263 (1) 311 (1) 291 (1) 267 (1) 309 (1) 290 (1) 266 (1) (1) 284 (1) 264 (1) 308 (1) 289 (1) 262 (1) 306 (1) 288 (1) 263 (1) (1) 281 (1) 261 (1) 308 (1) 287 (1) 261 (1) 306 (1) 286 (1) 261 (1) Corrigendum 3945