OPINION VVhither breast • • •Imaging In South Africa? IJ Movson MBChB, DMRD (London) Consultant Radi%glst, Department of Radiology, Addmgton Hospital, University of Nata/ Weare living in an age of sophisticated technology in which the explosion of scien- tific data and research is tending to over- whelm us. Itis an age in which it is becom- ing impossible for one person to have an in- depth knowledge of every branch of radi- ology. We need to keep a sense of pro portion, a sense ofbalance. The philosophy of using a machine gun to shoot a fly instead of a fly swatter is an expensive one. People are not even aware that they are practising this phi- losophywhich is unrealistic in this age of cost consciousness. This is especially relevant in SouthAfrica where the health budget is lim- ited, and will be so for a longtime. The breast is a skin appendage with straightforwardanatomy with arelatively Urn- ited nurnber of pathologies affecting it. For practical purposes the whole of mammography is dedicated to the early diag- nosis ofbreast carcinoma, in an attempt to in- fluence favourably the prognosis andsurvival rate of this common disease which affects ap- proximately 10% of the female population. The fact that there is such a plethora of mammographic publications in every radio- logical journal, shows how little we under- stand the disease andhowrelativelyprimitive is our ability to diagnose this condition early. In spite of all the modalities we have, the an- tidpated reduction of mortality ofbreast car- cinomain a screened population is 30%. This is substantial but illustrates once again, how inadequate our current knowledge is, because 70% of the targeted population has not been helped. My remarks are to emphasise the need for a realistic cost effective approach. Film screen mammography Themainstay of the diagnosis ofbreast dis- ease will for a long time depend on a founda- tionmade up of three layers: • Clinical examinations • Ftlmscreenmammography • Ultrasound In selling real estate we all know that the three most important factors in selling a home are location, location, location. In marnmographywe also have three important factors for success, namely dedication, dedi- cation, dedication, This dedication must start with the radi- olcgstundertakingmammographywho must be familiar with every facet of the subject. He or she must know how to achieve the best possible diagnostic radiograph with the equip- ment available. The technical side of mammography including quality control, is welldocurnented. The radiologist must work step by step with the radiographer in the pro- duction of the mammogram, which means tailoring views required to solve a particular problem. Mostofusdoingmammographyin 4 SAJOURNAL OF RADIOLOGY. November 1996 South Africa are self taught, and this includes our radiographers. Specialised courses forra- diographe.rs and radiologists are not freely available in South Africa. Most of us have learned by trial and error. Having visited mammographic centres in Britain and the USA, I am convinced we can produce excel- lent work by our dedication to mammography. Ifyou cannot send yourra- diographers on dedicated courses, try to send her to a local mammography centre where good work is being done. There is an excel- lentvideo film which was produced by the American College of Radiology. It is worth purchasing this video which can be repeat- edly reviewed by the mammographers in your department. This video becomes a readily available hands-on teacher for all the staff doing mammography, especially for those in relatively isolated situations (Ameri- can College ofRadiology). Radiologists should also try to visit dedi- cated centres overseas, and ifthis isnotpossi- ble,visitlocal centres dedicated to good work We have to be constantly self critical, and to constantly review the quality of our work It is amazing with intelligent experience, how quality does improve. Try to do double read- ingwherever possible. Ifthis is not possible, keep your problem cases aside and discuss them with another colleague involved in mammography. The question of whether a radiologist should be involved in breast examination of the patient remains controversial. I person- allystrongly believe that this should be done. In our department, after the mammogram has beenreviewed by the radiologist, the pa- tient is informed that we prefer to examine the patient and that after the examination we again review the mammogram to decide whether we require further views or ultrasonographyforfurther elucidation, Weknowthatinasmanyas lS%ofcases, a clinicallypalpable mass maynotbe detected at mammography. By constantly practising clinical examination together with the topage5 Whither breast irnaging in South Africa? frompage4 mammographic and ultrasonographic find- ings at hand, the dedicatedmammographer can become skilled in interpretation of breast disease. On occasions a carcinoma missed by the surgeon or by an experienced gynaecologist is found by the radiologist because he or she has the added advantage of seeing the mammogram before examin- ing the patient. This holistic approach to medicine is worth striving for. Young people under the age of30years are not infrequently sent to our depart- ment. Doctors often do not understand the limitations and undesirability of doing mammography at such an early age. Under these circumstances, we refer the patient to a breast surgeon for opinion. The exami- nation is initially limited to a medio-lateral oblique view. The cranio-caudal view is only done if it is felt that this view will be contributory. We often complement this investigation with a breast ultrasound ex- amination. If there is a strong family history of breast carcinoma at an early stage, i.e. the patient's mother or sister had a carcinoma at an early age, our criterion for not under- taking the mammogram is not so strict. Itisimportantto establish a rapport with one's referring colleagues and to assure them that we are not competing with them - we· are after all,on the same side,namely the side of the patient. As a radiologist, I do not think it is our duty to supersede the referring sur- geon in giving advice. Itis best to leave this to the doctor who is treating the patient. I al- ways explain this to the patient and this can avoid unpleasantness with one's colleagues. Itis always important to obtain a follow- up histological report of all cases which have had a biopsy. This is the best way to learn and to get perspective of which way our as- sessment of mammograms is going. I would like to comment on a fewprac- tical points which are of relevance and are contributory towards achieving excellence: 1.A dedicated viewing box is an essential requirement for adequate mammography. If you do work without such a box, the dif- ference with one is unbelievable. Most or- dinary boxes have a weaker light than the dedicated box. This results in underillumination of the mammogram. I am sure that all radiologists involved in mammography will confirm that underillumination and underpenetration of the breast associated with inadequate compression of the breast are very impor- tant reasons for the missed diagnosis of breast carcinoma. Adequate processing is of course absolutely essential. 2.With regard to exposure factors, we try and work within the 100-200 mAs range. We have found we get our most diagnostic studies in the range. With experience, the radiographer can adjust her initial Kv read- ing and density to obtain the above mAs. 3.1t is important to choose a radiographer with empathy for her patients to do mammography. The patients coming for mammography are amongst the most frightened and apprehensive in the world - frightened about the procedure and ap- prehensive, with good reason, about the outcome of the examination. "Is this can- cer doctor"? is the standard question we are askeel. Mammography currently remains an art in spite of all the scientific background for this procedure. Ultrasonography Ultrasonography' of the breast is an ab- solute necessity in any mammographic de- partment. For some time the main use of ultrasonography has been in differentiating solid from cystic lesion, but not absolutely for a solid lesion. Where possible, one should have avail- able high resolution real-time equipment, preferably linear array transducers of 7-10 mHz frequency. The technique of ul- trasound of the breast is well documented, The ideal situation would be for the 5 SAJOURNAL OF RADIOLOGY. November 1996 mammographer doing the clinical and mammographic examination to also be able to do the ultrasound examination. For many reasons this is not always possible. Ultrasound is a modality useful in solv- ing mammographic and clinical problems. It is universally not accepted as a breast screening modality at this point in time. It is most often used in assessing indetermi- nate masses with well defined or poorly seen margins. When a mass is palpable and not visible on a mammogram, especially in the dense breast, ultrasound is used to dif- ferentiate solid from cystic lesions. If solid, biopsy may have to be considered. With modern equipment one can di- agnosecysts 2-3 mmindiarneter. Itisim- portant to realise that large deeply situated cysts within a large fatty breast may remain undetected. Calcified circumscribed masses do not require an ultrasound exami- nation. They are usually due to an involut- ing fibroadenoma. Pleomorphic microcalcification with a mass usually re- quires a biopsy to exclude malignancy. Ultrasound is useful to assess inflamma- tory disease and to assist in the diagnosis of breast abscessor post surgical fluid collection. More and more radiologists are trying to make a definitive diagnosis ofbreast car- cinoma by ultrasound, but according to the literature, ultrasound has too high a false negative rate, to be acceptable as a screen- ing modality. It also cannot detect nne micrccalclfications as well as mammography can. Ultrasound also has a distinct false positive rate. Ultrasound is now being used for guided aspirations, core biopsy and needle localisation of solid le- sions visible at ultrasound. Ultrasound guided mammotomy A new technique of ultrasound guided mammotomy is being developed. A new biopsy device, a mammotome, uses a topage6 Whither breast imaging in South Africa? fram page 5 vacuum within a tissue transport mecha- nism, enablingmultiple tissue sampling with one insertion of the instrument under ul- trasound guidance. This method gives a better and more accurate sampling ofbreast tissue suspicious of malignancy. Colour Dopp'ler ultrasounCl The principle of this technique' isbased on the fact that tumours larger than a few millimetres stimulate neovascularisation. These give rise to flow signals which can be detected as high velocity signalsof a spe- cific nature. High velocity flow is detected only in malignancies. There is the poten- tial with this technique to differentiate malignant from benign lesions. Cancers as small as 10 mm are found to be positive for flow signals. Recently there has been the addition of a micro bubble contrast agent for colour Doppler ultrasound. Anew agent, Levovist (SHU S08A; ScheringAG) has been devel- oped, and contains micro bubbles small enough to cross the lung barrier. This tech- nique increased the sensitivity and specificityoffour patients to 100% enabling the accurate differentiation of benign masses from carcinoma- .This work in progress is very exciting and hopefully will have a great future. Other methods ofbreast imaging are as follows: Xeromammography This modality, which was popular for several years, has been phased out by the excellence of modem film screen equip- ment. Xeromarnmography is no longer used in South Africa. y Technetium 99-M Sestarnibi is being used experimentally to try and improve the sensitivity and specificity in the diagnosis of breast carcinoma. This compound is a cardiac perfusion agent which accumulates in myocardial tissue in proportion to the re- gional coronary blood flow'. The effective- ness is as yet unknown and is not a method for general use at this stage. Digital mammography computer ~Ided diagnOSIs This modality is in the developmental stage and may well have a great future. "Thus far no artificial intelligence system that derives its input directly from a mammographic image has been shown to improve accuracy of diagnosis beyond that of an unaided radiologist". The role of MRI in assessing and managing 6reast disease "The value ofMRI for breast cancer is as yet not widely accepted by the medical community, let alone the public. Finally,the cost of contrast enhanced magnetic reso- nance imaging and scarcity of magnetic resonance units capable of performing an adequate breast study prohibits examina- tion of even a fraction of the adult female population" .6 I think this one sentence describes in a succinct way the current sta- tus of this modality, very applicable to our situation in South Africa. It would appear that there is a consensus of opinion that MR! should be confined to certain difficult cases,and that decisions in clinical manage- ment must be made together with mammographic and clinical information. Position emission tomography - PET PET is a very specialised expensive form of nuclear medicine not readily availablefor general use in this country in the foresee- able future. The current opinion is that PET may have an important role as a 6 SA JOURNAL OF RADIOLOGY. November 1996 non-invasive early indicator oftreatrnent ef- ficacy,andmaytherefore have a role in plan- ning chemotherapy. 7 Conclusion Different methods of breast imaging have been described. Some have been dis- carded and some are in the investigative and developmental stage. Some of these are time consuming and expensive. They can only be done in special cases. Research must continue, and hopefully our diagnosis of breast carcinoma will be successful at an early stage. For practical purposes however, we have to rely on modalities which are af- fordable and accessible to most people, in a country such as ours and probably the world at large. These modalities are mammography and ultrasonography. References 1 Valerie P, Jackson MD. The Current Role of U1trasonographyinBreastlmaging RCNAVol33, No 6; NovtmI:x:Y1955. 2 ParkerSH, Dennis MA, StavrosAT,Johnson KI<. Ultra- sound Guided Mammotomy-A New Breast Biopsy TErlmiquelDMSl2: 113-118;Mayt1une 1996. 3 Keder RP, Cosgrove 0, McReady VR, Bamber KC, Carter ER: Micro Bubble ContrastAgent for Color Dop- pler US: Effect on BreastMasses. Work in Progress: Radi· duu.1996; 198:679-686. 4 Khalkhali, Cutrone JA, Mena lG et al. Scintimammography:The Complementary RoleofIc- PPm Sestamibi Prone Breast Imaging ForThe Diagnosis of BreastCarcinoma.Rat/idogy 1995: 196;421-426. 5 StephenAGeig&MartinJYaffeDigitalMammography, Computer Aided Diagnosis, andTelemammography. RCNANovtmI:x:Y 1995:p1205. 6 Teresa A Coons, PHD - MRl's Role in Assessing and ManagingBreastDisease.Rmli%gia:dTlÓlno/nty,March! April1996.vol67:No4;p311-336. 7 Dorit 0, Adler and L Wahl RL: New Methods for lmagingThe Breast. Techniques, Findings and Potential. AIR, 1995;164: 19-30