FMISO-PET & perfusion CT at baseline & week 2 CRT as predictive markers for response in rectal cancer

Abstract

FMISO-PET & perfusion CT at baseline &week 2 CRT as predictive markers for response in rectal cancer

Full text

ESTRO 2017
Poster
presented at:
Results
Characteristics
▪11 patients with locally advanced rectal adenocarcinoma were recruited
▪All patients had neoadjuvant CRT 45 Gray in 25 fractions with concurrent
Capecitabine chemotherapy twice daily
▪Imaging was done at median 1 (range 0-14) days before CRT and on day of
fraction 10 (7-15) during CRT
▪After CRT, 8 (73%) underwent total mesorectal excision, 2 (18%) active
surveillance and 1 (9%) declined surgery
▪Patients were classed as good (n=6) or poor (n=5) responders based on AJCC
v7.04tumour regression grade or response on endoscopy/MRI if no surgery
•Median age 67 (IQR 19)
•9 male (82%)
•
Stage T2 2 (18%), T3 9 (82%)
•
Stage N0 4 (36%), N1 6 (55%), N2 1 (9%)
FMISO-PET & perfusion CT at baseline & week 2 CRT
as predictive markers for response in rectal cancer
T Greenhalgh1, J Wilson2, T Puri1, J Franklin1, L Wang4, R Goldin5, K Chu1, V Strauss6, M Partridge1, T Maughan1
1. Department of Oncology, University of Oxford, UK, 2. Institute of Cancer Research, London, UK, 3. Department of Pathology, Oxford University Hospitals NHS Foundation Trust, UK
4. Centre for Pathology, Imperial College London, UK, 5. Centre for Statistics in Medicine, Oxford Clinical Trials and Research Unit, University of Oxford, UK (Clinical Track: Lower GI)
Conclusions
References:
1. National Institute for Health and Care Excellence. Colorectal cancer: diagnosis and management (CG131). 2011
2. Zorcolo L et al. Ann Surg Oncol. 2012;19(9):2822-32
3. Horsman MR et al. Nature Reviews Clinical Oncology 2012;9(12):674-687
4. Compton CC et al. AJCC Cancer Staging Atlas. New York: Springer-Verlag; 2012
Methods
Background
FMISO PET
▪1 patient did not undergo FMISO scanning due to tracer not being available
▪8/10 4-hour scans were evaluable at baseline and 8/9 during week 2 CRT
▪In 5/7 patients with paired evaluable scans, the T:M ratio reduced however this
showed no correlation with outcome (Table 2, Figure 2)
▪Reasons for scans being unevaluable were (Figure 3):
•Non-tumour uptake in the lumen due to colonic excretion of FMISO
•Spill-in from adjacent bladder activity
pCT
▪All patients had evaluable pCT at baseline and week 2 CRT (Table 1)
▪There was no relationship with response seen (Figure 1)
▪Patients were recruited from Churchill Hospital, Oxford University Hospitals NHS
Foundation Trust, UK from October 2013 to April 2016
▪Inclusion criteria were:
•Undergoing neoadjuvant CRT for confirmed rectal adenocarcinoma
•≥18 years old with performance status 0-2
•MRI demonstrating mesorectal fascia, levators or anal sphincter were involved or
threatened (≤1mm) by tumour
▪Imaging with FMISO-PET and pCT was done at baseline and during week 2 CRT
▪FMISO SUVmax, pCT blood flow (BF) and blood volume (BV) were obtained:
•Tumour region of interest (ROI) outlined by radiologist on contemporaneous T2W MRI
•Rigid registration and transposition of ROI to pCT or FMISO-PET CT on Varian Eclipse
•FMISO-PET tumour (T) and muscle (M) SUVmax obtained using PMOD software
•GE perfusion 4.0 maps created and analysed using MIRADA DBx to obtain BV and BF
Parameter Baseline Week 2 CRT
BV 3.2 (2.1) 2.8 (2.2)
BF 23.2 (18) 21 (38.3)
Table 1: Median BV and BF (IQR) at baseline and
during chemoradiotherapy
Figure 1: Change in median BF (a) & BV (b)
from baseline to week 2 CRT
Poor (red) or good (blue) response
a
b
Contact: Tessa.Greenhalgh@oncology.ox.ac.uk
▪In this small pilot study, a reduction in FMISO uptake was not predictive of
response based on tumour regression grade/clinical outcome measures
▪Significant challenges in delivery and interpretation of FMISO PET scanning for
rectal cancer were seen, in particular related to excretion of FMISO
▪No association was seen between perfusion CT parameters and response -
larger scale studies would be required to establish the value of this modality
▪Patients with locally advanced rectal cancer are considered for neoadjuvant chemo-
radiotherapy (CRT) if they have high risk operable or borderline/unresectable disease1
▪Around 15% of patients having CRT have a complete pathological response with a similar
proportion showing minimal tumour response2
▪Hypoxia reduces response to RT and is associated with a more aggressive phenotype3
▪This study explores the predictive value of hypoxia functional imaging using FMISO-PET
and perfusion CT (pCT) in patients undergoing CRT for rectal cancer
#
Response
T:M
SUVmax
(baseline)
T:M
SUVmax
(on CRT)
T:M %
change
1
Good
1.4
2.2
157%
2
Good
U/E
U/E
U/E
3
Poor
2.4
1.6
67%
4
Poor
2.8
2.1
75%
5
Good
U/E
1.4
U/E
6
Poor
1.6
N/A
N/A
7
Good
2.3
1.6
71%
8
Good
2.2
1.3
59%
9
Poor
2.1
1.3
62%
10
Good
N/A
N/A
N/A
11
Poor
1.1
1.3
119%
a
b
Figure 2:
Patient 1 FMISO-PET at
baseline (a) and week 2 CRT (b)
(Rectal
tumour red, muscle
orange)
Figure 3: Example of activity seen
due to FMISO excretion in
bladder and bowel
Table 2: Change in Tumour:Muscle (T:M) SUVmax
ratios between baseline and week 2 CRT
U/E unevaluable, N/A non-applicable
EP-1278
Tessa Greenhalgh DOI: 10.3252/pso.eu.ESTRO36.2017
Clinical track: Lower GI (colon, rectum, anus)