Journal of Surgical Oncology 2011;103:741

LETTER TO THE EDITOR

Monitoring Response to Neo-Adjuvant Chemotherapy

With F-18 FDG PET/CT

To the Editor

In recent issue of the Journal of Surgical Oncology, Choi et al. [1]

evaluated the role of PET/CT to neo-adjuvant chemotherapy in

advanced breast cancer compared with ultranosography (US) and

magnetic resonance imaging (MRI). The authors concluded that

MRI is better than PET/CT in monitoring the effect of neo-adjuvant

chemotherapy in advanced breast cancer.

For assessment of clinical response of US and MRI during neo-

adjuvant chemotherapy, authors used Response Evaluation Criteria in

Solid Tumors (RECIST) [2], which is one of the most widely applied

criteria for tumor size measurement. Since PET/CT provides metabolic

and functional information, which is not applicable to RECIST criteria,

authors used EORTC (European Organization of Research and

Treatment of Cancer) guidelines [3]. The authors wrote that they kept

with the EORTC guidelines and defined >50% decline of peak

standardized uptake value (pSUV) on FDG metabolism as complete

response. However, according to the EORTC recommendations,

complete metabolic response would be complete resolution of F-18

FDG uptake within the tumor volume so that it was indistinguishable

from surrounding normal tissue [3]. There is no mentioning about 50%

decline of pSUV in EORTC recommendations. Also, partial metabolic

response is classified in EORTC recommendations as 15–25%

reduction in SUV after one cycle of chemotherapy or more than 25%

reduction after one treatment cycle, which was not used in this

manuscript. For US and MRI, authors assessed of clinical response as

complete response, partial response, and stable disease. On the other

hand, for the PET/CT, authors assessed of clinical response only as

responder and non-responder, which is discriminating against other

modalities.

In other studies, PET/CT shows accurate prediction of pathologic

response compared to the other modalities in breast cancer [4–7]. In

this manuscript, comparing the other modalities with inappropriate

metabolic response criteria seems to make this study biased. Therefore,

it is difficult to derive such a conclusion in this article that MRI is better

than PET/CT in monitoring the effect of neo-adjuvant chemotherapy in

advanced breast cancer due to wrong metabolic response criteria [1].

Young Hwan Kim, MD

Yun Young Choi, MD*

Department of Nuclear Medicine

Hanyang University Medical Center

Seoul, Republic of Korea

REFERENCES

1. Choi JH, Lim HI, Lee SK, et al.: The role of PET CT to evaluate theresponse to neoadjuvant chemotherapy in advanced breast cancer:Comparison with ultrasonography and magnetic resonance imag-ing. J Surg Oncol; 102:392–397.

2. Therasse P, Arbuck SG, Eisenhauer EA, et al.: New guidelines toevaluate the response to treatment in solid tumors. EuropeanOrganization for Research and Treatment of Cancer, NationalCancer Institute of the United States, National Cancer Institute ofCanada. J Natl Cancer Inst 2000;92:205–216.

3. Young H, Baum R, Cremerius U, et al.: Measurement of clinicaland subclinical tumour response using [18F]-fluorodeoxyglucoseand positron emission tomography: Review and 1999 EORTCrecommendations. European Organization for Research and Treat-ment of Cancer (EORTC) PET Study Group. Eur J Cancer 1999;35:1773–1782.

4. Rousseau C, Devillers A, Sagan C, et al.: Monitoring of earlyresponse to neoadjuvant chemotherapy in stage II and III breastcancer by [18F]fluorodeoxyglucose positron emission tomography.J Clin Oncol 2006;24:5366–5372.

5. Shankar LK, Hoffman JM, Bacharach S, et al.: Consensusrecommendations for the use of 18F-FDG PET as an indicator oftherapeutic response in patients in National Cancer Institute Trials.J Nucl Med 2006;47:1059–1066.

6. Berriolo-Riedinger A, Touzery C, Riedinger JM, et al.: [18F]FDG-PET predicts complete pathological response of breast cancer toneoadjuvant chemotherapy. Eur J Nucl Med Mol Imaging 2007;34:1915–1924 .

7. Smith IC, Welch AE, Hutcheon AW, et al.: Positron emissiontomography using [(18)F]-fluorodeoxy-D-glucose to predict thepathologic response of breast cancer to primary chemotherapy.J Clin Oncol 2000;18:1676–1688.

*Correspondence to: Yun Young Choi, MD, Department of NuclearMedicine, Hanyang University Medical Center, 17, Haengdang-dong,Seongdong-ku, 133-792, Seoul, Republic of Korea. Fax:þ82-2-2281-0475.E-mail: yychoi@hanyang.ac.kr

Received 2 November 2010; Accepted 10 November 2010

DOI 10.1002/jso.21834

Published online 15 January 2011 in Wiley Online Library(wileyonlinelibrary.com).

� 2011 Wiley-Liss, Inc.