E U R O P E A N U R O L O G Y 6 1 ( 2 0 1 2 ) e 4 4

avai lable at www.sciencedirect .com

journal homepage: www.europeanurology.com

Letter to the Editor

Reply to Carl J. Rossi, Jr.’s Letter to the Editor

re: Sung Kim, Shunhua Shen, Dirk F. Moore, et al.

Late Gastrointestinal Toxicities Following Radiation

Therapy for Prostate Cancer. Eur Urol 2011;60:908–16

We appreciate the concerns expressed by Dr. Rossi and the

opportunity to respond and to clarify. Our analyses, based

on Surveillance Epidemiology and End Results (SEER)–

Medicare linked data, showed substantial differences in

gastrointestinal (GI) toxicity rates at 4 yr among various

modalities: 8.5% for protons, 4.8% for three-dimensional

conformal radiotherapy (RT), 3.5% for combination external-

beam RT plus brachytherapy, 3.3% for intensity-modulated

RT, and 2.5% for brachytherapy [1]. Dr. Rossi suspected that

variations in radiation technique, such as total dose, rectal

margin, and beam arrangement, were factors possibly

influencing GI toxicity due to proton radiation and that,

over time, advances like better beam arrangement have

improved outcomes. Because the SEER-Medicare linked

database does not provide specifics of radiation treatment

such as dose or rectal margin, the risks reported in our paper

are broad comparisons among various radiation modalities

for the time we studied (1992–2005).

Our data also show that as experience accumulates over

time, proton therapy is associated with less GI toxicity in

more recent years. Our reporting of early proton toxicity is

not an indictment of proton therapy as a modality for

treating prostate cancer but rather a recognition that the

latest technology is not necessarily the safest, especially in

DOIs of original articles: 10.1016/j.eururo.2011.05.052, 10.1016/j.eururo.20

0302-2838/$ – see back matter # 2012 European Association of Urology. Publis

the early years after that technology is introduced. Proton

therapy for prostate cancer has recently been reported to

cause very low rates of acute and chronic GI toxicity in a

large multi-institutional experience [2]. As proton therapy

becomes a more common treatment modality for prostate

cancer, we look forward to seeing future toxicity data as it

becomes available.

Conflicts of interest: The authors have nothing to disclose.

References

[1] Kim S, Shen S, Moore DF, et al. Late gastrointestinal toxicities follow-

ing radiation therapy for prostate cancer. Eur Urol 2011;60:908–16.

[2] Nihei K, Ogino T, Onozawa M, et al. Multi-institutional phase II

study of proton beam therapy for organ-confined prostate cancer

focusing on the incidence of late rectal toxicities. Int J Radiat Oncol

Biol Phys 2011;81:390–6.

Sung Kim

Weichung J. Shih

Grace L. Lu-Yao*

Robert Wood Johnson Medical School, New Brunswick, NJ, USA

*Corresponding author. Cancer Institute of New Jersey,

School of Public Health, University of Medicine and Dentistry in

New Jersey, Robert Wood Johnson Medical School,

195 Little Albany Street, New Brunswick, NJ 08901, USA.

E-mail address: luyaogr@umdnj.edu (G.L. Lu-Yao)

January 31, 2012

Published online on February 7, 2012

12.01.053

hed by Elsevier B.V. All rights reserved. doi:10.1016/j.eururo.2012.01.054