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| Cancer diagnosis |
Radiological procedures | |
They most often confirm and objectify clinically suspected lesions and reveal new lesions, thus modifying the staging and treatment possibilities.
Main radiological procedures include:
This very simple procedure is most useful for the diagnosis of primary lung tumours, pulmonary metastases, pleuritic or parietal localisations, as well as the study of infectious complications or post-therapeutic pulmonary fibrosis.
Since it can be performed within a very short timescale (in comparison with CT-Scan or RMI) , this simple examination should be used as often as possible.
We have gathered a few signifiant images borrowed from the Virtual University of Rennes University 1 (France)
X-Ray pictures should be requested by the physician as often as needed, thoracic CT-Scan has not totally replaced it for at least two reasons:
Standard bone X-Rays may show either primitive bone tumours, or more often bone metastases which can be of three different aspects:
- lytic lesions: local disappearance of the bone structure (metastasis from kidney, lung, head and neck, and many other malignant tumours),
- dense lesions: local densification of the bone structure (metastasis from breast, prostate or thyroïd carcinoma),
- joint lesions (lytic and dense).
Quickly obtaining a bone X-Ray is mandatory when the patient is suffering from pain evoking a pre-fracture syndrome.
X-Ray very often allows a rapid diagnosis, for example when a risk of medullar compression is suspected, through the discovery of irregular vertebral crushes or the disappearance of vertebral pedicles.
A bone scintigraphy may help in requesting the appropriate radiography by localising the lesion.
The following pages demonstrate a few diagrammatic aspects of bone X-Rays for discovering bone metastases:
Bone RMI (see below) is another precious tool for studying cancer-related bone lesions, but once more, the great simplicity involved in obtaining a simple bone radiography (specifically in emergency) renders this latter examination the first one to request in many circumstances
Mammography is the leading examination for diagnosis of breast cancer.
Technical improvements have been made over the last ten years, and further progress is pending (digitalisation for instance).
Nowadays, tumours as small as 4 mm in diameter can be detected (infraclinical tumours) with the usual typical image of a dense, poorly delineated, star-like opacity harbouring a few microcalcifications.
Biopsies, now performed in stereotaxic conditions, offer pre-operative histological information.
Here are the various chapters you can consult over the following pages:
Tomodensitometry or computed tomography (scan) is one of the major tools for diagnosing cancer in almost any part of the body.
Lesions (primitive tumour, deeply located nodes, metastases) whose volume is greater than 1 cm are relatively easy to detect.
Enhanced contrast with the use of iodine products is characteristic of increased vascularisation, frequently observed in cancer lesions.
New modern devices (helical and multisclice devices) allow very thin jointive slices, with minimal patient irradiation, performed in a short time thus eliminating artefacts due to respiratory movement which decrease the size of detectable pathological images.
CT scan can detect relatively deep lesions thus enabling biopsies to be performed to obtain the histological proof of cancer.
CT scan has now become the best device to define target volumes for radiotherapy and to calculate preradiotherapy dosimetry.
A few views have been pooled together in a special chapter, most of them borrowed from various sites. We have produced a diagram with comments for each view in order to assist interpretation.
- Head and neck scan,
- Thorax scan,
- Upper abdominal scan (liver - pancreas - biliary ducts),
- Lower abdominal scan (retroperitoneal region),
- Pelvis scan.
Magnetic resonance imaging initially offered very interesting images in neurological and osseous pathologies.
Its actual definition is somewhat lower than scanner definition, however devices are constantly becoming more rapid and effective Indications are therefore ever-increasing and gradually differentiated from those of CT scanners.
In particular, many studies are currently underway to objectivise the initial changes induced by chemotherapy, radiotherapy or new target treatments and to predict clinical responses to treatment.
Another very attractive indication might be the surveillance of irradiated tumours (in particular breast carcinoma).
With no intended pretence, we have pooled together a few RMI views with the same educational tools and goals:
Pedal lymphography is still used for lymphoma and by a few teams in cervix uteri carcinoma.
Angiographic procedures are less frequently used than in the past: they enabled viewing of anarchical tumour vascularisation (particularly in renal or brain tumours). They may also be used for therapeutic acts such as chemoembolisation or intraarterial chemotherapy.
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