In this chapter, we describe the role of imaging in restaging rectal cancer after preoperative neoadjuvant chemoradiation therapy (CRT); especially we focused on its potential role in the prediction of complete tumor regression (pCR). On standard MRI, a normalized rectal wall without any detectable wall thickening is considered a definite criterion for a pCR. On diffusion-weighted MR imaging (DWI), strength of evidence scored as moderate (2/5) the value of pretherapy apparent diffusion coefficient (ADC) as possible indicator of outcome of therapy and as moderate-firm percentage increase of ADC value measurement during treatment for personalized treatment management. On posttreatment presurgical evaluation, the challenge will remain the detection of microscopically small clusters of residual tumor cells, which are difficult to detect—even at histology—and are currently beyond the detection level of any available imaging modality.
FDG PET-CT shows great promise as a tool to evaluate the effectiveness of rectal cancer neoadjuvant therapy as it has demonstrated high predictive value in several studies. However, it is important to note that also PET cannot be considered as surrogate for pCR because patients with complete PET response after neoadjuvant CRT often show residual microscopic disease. However, promising data derive from metabolic response assessment during neoadjuvant CRT allowing for tailored therapy using alternative dosing, fractionation, or agents.
We describe in the text and analyze in the figures the advantages and disadvantages of these techniques in rectal cancer response evaluation and whether they can be complementary.
Rectal Cancer Apparent Diffusion Coefficient Standardize Uptake Value Advanced Rectal Cancer Total Lesion Glycolysis
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Maas M, Nelemans PJ, Valentini V et al (2010) Pathologic complete response after chemoradiation for rectal cancer is associated with improved long-term outcome: a pooled analysis of 3105 patients. Lancet Oncol 11(9):835–844PubMedCrossRefGoogle Scholar
Lambrecht M, Vandecaveye V, De Keyzer F et al (2012) Value of diffusion-weighted magnetic resonance imaging for prediction and early assessment of response to neoadjuvant radiochemotherapy in rectal cancer: preliminary results. Int J Radiat Oncol Biol Phys 82(2):863–870PubMedCrossRefGoogle Scholar
Kang JH, Kim YC, Kim H et al (2010) Tumor volume changes assessed by three-dimensional magnetic resonance volumetry in rectal cancer patients after preoperative chemoradiation: the impact of the volume reduction ratio on the prediction of pathologic complete response. Int J Radiat Oncol Biol Phys 76(4):1018–1025PubMedCrossRefGoogle Scholar
Barbaro B, Fiorucci C, Tebala C et al (2009) Locally advanced rectal cancer: MR imaging in prediction of response after preoperative chemotherapy and radiation therapy. Radiology 250(3):730–739PubMedCrossRefGoogle Scholar
Barbaro B, Vitale R, Leccisotti L et al (2010) Restaging locally advanced rectal cancer with MR imaging after chemoradiation therapy. Radiographics 30(3):716–719CrossRefGoogle Scholar
Dzik-Jurasz A, Domenig C, George M et al (2002) Diffusion MRI for prediction of response of rectal cancer to chemoradiation. Lancet 360(9329):307–308PubMedCrossRefGoogle Scholar
Sun YS, Zhang XP, Tang L et al (2010) Locally advanced rectal carcinoma treated with preoperative chemotherapy and radiation therapy: preliminary analysis of diffusion-weighted MR imaging for early detection of tumor histopathologic downstaging. Radiology 254(1):170–178PubMedCrossRefGoogle Scholar
Lambrecht M (2010) The use of FDG-PET/CT and diffusion-weighted magnetic resonance imaging for response prediction before, during and after preoperative chemoradiotherapy for rectal cancer. Acta Oncol 49:956–963PubMedCrossRefGoogle Scholar
Kim SH, Lee JY, Lee JM, Han JK, Choi BI (2011) Apparent diffusion coefficient for evaluating tumour response to neoadjuvant chemoradiation therapy for locally advanced rectal cancer. Eur Radiol 21(5):987–995. doi:10.1007/s00330-010-1989-yPubMedCrossRefGoogle Scholar
Patterson DM, Padhani AR, Collins DJ (2008) Technology insight: water diffusion MRI-a potential new biomarker of response to cancer therapy. Nat Clin Pract Oncol 5(4):220–233PubMedCrossRefGoogle Scholar
Kim SH, Lee JM, Hong SH et al (2009) Locally advanced rectal cancer: added value of diffusion-weighted MR imaging in the evaluation of tumor response to neoadjuvant chemo- and radiation therapy. Radiology 253(1):116–125PubMedCrossRefGoogle Scholar
Lambregts DM, Vandecaveye V, Barbaro B et al (2011) Diffusion-weighted MRI for selection of complete responders after chemoradiation for locally advanced rectal cancer: a multicenter study. Ann Surg Oncol 18(8):2224–2231PubMedCrossRefGoogle Scholar
Kierkels RG, Backes WH, Janssen MH et al (2010) Comparison between perfusion computed tomography and dynamic contrast-enhanced magnetic resonance imaging in rectal cancer. Int J Radiat Oncol Biol Phys 77(2):400–408PubMedCrossRefGoogle Scholar
Cascini GL, Avallone A, Delrio P et al (2006) 18F-FDG PET is an early predictor of pathologic tumor response to preoperative radiochemotherapy in locally advanced rectal cancer. J Nucl Med 47:1241–1248PubMedGoogle Scholar
Janssen MH, Ollers MC, Riedl RG et al (2010) Accurate prediction of pathological rectal tumor response after two weeks of preoperative radiochemotherapy using (18)F-fluorodeoxyglucose-positron emission tomography-computed tomography imaging. Int J Radiat Oncol Biol Phys 77(2):392–399PubMedCrossRefGoogle Scholar
Janssen MH, Ollers MC, van Stiphout RG et al (2012) PET-based treatment response evaluation in rectal cancer: prediction and validation. Int J Radiat Oncol Biol Phys 82(2):871–876PubMedCrossRefGoogle Scholar
Capirci C, Rampin L, Erba PA et al (2007) Sequential FDG-PET/CT reliably predicts response of locally advanced rectal cancer to neo-adjuvant chemo-radiation therapy. Eur J Nucl Med Mol Imaging 34:1583–1593PubMedCrossRefGoogle Scholar
Melton GB, Lavely WC, Jacene HA et al (2007) Efficacy of preoperative combined 18-fluorodeoxyglucose positron emission tomography and computed tomography for assessing primary rectal cancer response to neoadjuvant therapy. J Gastrointest Surg 11:961–969PubMedCrossRefGoogle Scholar
van Stiphout RG, Lammering G, Buijsen J et al (2011) Development and external validation of a predictive model for pathological complete response of rectal cancer patients including sequential PET-CT imaging. Radiother Oncol 98:126–133PubMedCrossRefGoogle Scholar