IMAGING NEWS
Ultrasound-guided surgery best for removal of breast tumours
The use of ultrasound-guided surgery
(USS) to remove tumours from women who have palpable breast cancer is much more successful than standard surgery in excising all the cancerous tissue while sparing as much healthy tissue as possible. This is the conclusion of a randomised controlled trial (RCT) presented by Dr N Krekel of the VU Medical Center in Amsterdam at the recent European Breast Cancer Conference. Currently, palpable tumours are excised without visual aid from tools to help locate the precise posi- tion of the tumour during surgery. The margin of “healthy” tissue is then analysed to check that it is free of cancer cells, and if it is not, then further surgery, or an addi- tional radiotherapy boost may be required. In the RCT, patients with palpable early
stage breast cancer were randomised to either USS or standard palpation-guided surgery (PGS). It was found that in the USS group only 3.3% of the margins con- tained cancerous cells compared with 16.4% among the PGS group. As a result, USS resulted in a significant reduction in re-excisions, mastectomies and extra radiotherapy. The amount of healthy tis- sue removed in the USS group was smaller than in the PGS group. The results show that USS can prevent the unacceptably high rate of margins containing cancer cells in palpable breast cancer excision, thus avoiding subsequent surgery or radiotherapy. Dr Krekel said the reason why USS was superior to PGS was because it enabled surgeons to “see” all round the tumour while they were performing the
new endoscope technology paves the way for ‘molecular-guided surgery’ for cancer
Recent research reported by Dr Zhen
Cheng at the recent meeting of the American Chemical Society (ACS) sug- gests that endoscope procedures might — in the future — use one of the newest and potentially most exciting upcom- ing fields of medical imaging, namely Cerenkov radiation. This is the phenom- enon responsible for the eerie blue glow in the cooling water of nuclear reactors. The potential of Cerenkov Lumines- cence Imaging (CLI) emerged recently when it was found that Cerenkov radia- tion could be harnessed in devices that do not involve nuclear power reactors. Laboratory experiments have shown that CLI can produce images of organs and also guide surgery for the removal of residual cancer cells in laboratory animals. It has also been found that CLI could dramatically improve the resolu- tion of PET scans, enabling PET scan- ners to detect smaller objects than previ- ously possible. Cerenkov luminescence is
APRIL/MAY 2012
especially exciting because its weak blue light can be detected with simple opti- cal sensors and is also compatible with commercially available optical imaging instruments and a wide selection of the nuclear imaging agents. However, the drawback is that the visible light barely penetrates deep tissues so limiting the usefulness of the approach. The combi- nation of Cerenkov luminescence with endoscopy (CLE) may however over- come this problem since with endos- copy, it is possible to get close enough to diseased tissue to take advantage of the technology. The results presented at the ACS showed the potential of the technology to enable molecular image- guided surgery by indicating the pres- ence of tumor tissue. In the experiments, the resolution of Cerenkov endoscopy was compared to white light imaging by analysing a commercial SPECT phan- tom filled with 18
F FDG. In addition, mice bearing C6 glioma tumors were DI EUROPE
operation. Intra-operative US enables the surgeon to optimally position the incision on the breast, and to operate under direct vision. The study thus offers the promise of more successful breast conserving surgery for women with early breast cancer. How- ever, this is a report from only one hospi- tal, and these findings need confirmation from other teams of surgeons before they should become standard practice.
http://tinyurl.com/Krekel-paper
injected intravenously to determine imaging feasibility in tissue. Before and after surgical removal of
the tumors,
CLI was performed on the mice using a fiber-based imaging system and com- pared to a commercial optical imaging
system.It was found that the resolution of thw system was than 1.2 mm. The in vivo tumor imaging study demonstrated the feasibility of using CLI to guide the resection of tumor tissues.
http://tinyurl.com/Cerenkov-Endoscopy
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