Cwikla, J. B.; Buscombe, J. R.; Kolasinka, A. D.; Parbhoo, S. P.; Deery, A.; Crow, J.; Thakrar, D. S.; Hilson, A. J.W.

Buscombe, J. R.; Cwikla, J. B.; Kolasinka, A. D.; Parbhoo, S. P.; Deery, A.; Crow, J.; Holloway, B.; Hilson, A. J.W.

A prospective trial was performed to assess the accuracy of 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) scintimammography and X-ray mammography in 18 patients (mean age 58 years, range 46-79 years) with suspected recurrent breast cancer in the breast and/or loco-regional tissues. All patients had been diagnosed to have breast cancer 1-23 years before scintimammography. Two patients had undergone mastectomy, so that a total of 34 breasts were studied with X-ray mammography and with prone-lateral and anterior scintimammography. Any abnormalities on X-ray mammograms and scintimammograms were noted, as was any additional local or nodal uptake of 99Tcm-MIBI. The nature of any lesion seen with either modality, or in which there was a clinical suspicion of recurrence, was confirmed by cytological or histological examination of tissue samples. There were nine breasts with recurrent cancer in eight patients. X-ray mammography identified six of these cancers. 99Tcm-MIBI scintimammography identified eight of nine recurrent breast cancers (the one cancer not seen was positive on X-ray mammography). In the 26 breasts without cancer, two were reported as having changes consistent with cancer and one was reported equivocal. There were three false-positive and one equivocal scintimammograms. The accuracy of 99Tcm-MIBI scintimammography within the breast (85%) was similar to X-ray mammography (82%). Axillary lymph node recurrence occurred in five patients, four of whom were positive with 99Tcm-MIBI. An additional patient had focal uptake of 99Tcm-MIBI at the site of recurrent cancer on the anterior chest wall. In conclusion, 99Tcm-MIBI scintimammography may provide useful complementary information in patients with suspected recurrence of cancer in the breast or loco-regional tissues.

Mammography, whilst remaining the fia st line imaging investigation of Suspected primary breast cancer, can be difficult to interpret ire patients with fibrous or dense breasts, Radionuclide imaging of the breast (scintimammography) has been suggested as an additional test. The aim of this study was to perform prospectively a comparison of the two techniques in a population with suspected breast cancer. Seventy such patients, mean age 54 years (range 57 years, 28-85) with 74 suspicious breast lesions were studied, They were imaged 5-10 min after intravenous injection of 740 MBq of Tc-99m sestamibi. Prone lateral and anterior supine views with and without markers were performed, all patients had histological confirmation of the nature of the breast lesions by limited incisional biopsy or definitive nide local excision, or cytological confirmation on fine needle aspiration. All patients had X-ray mammography. There were 53 malignant breast tumours and 21 benign lesions, Scintimammography correctly diagnosed 47 breast cancers, and yielded true-negative results in 12 benign breast lesions, There mere six cases of false-negative results and nine false-positive results, Four scans were reported as equivocal, The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 89%, 52%, 84% and 67%, respectively. X-ray mammography diagnosed correctly 37 malignant tumours, and in 12 benign lesions the results were true negatives. Ten studies were reported as equivocal. The sensitivity, specificity, PPV and NPV were 70%, 57%, 80% and 43%, respectively. The accuracy of Tc-99m sestamibi scintimammography was better than X-ray mammography though this was not significant (McNemar's test). Fewer equivocal results were obtained with scintimammography. Scintimammography may therefore hare a role in the diagnosis of primary breast cancer when X-ray mammography is equivocal or unhelpful.

Cwikla, J. B.; Barlow, R. V.; Buscombe, J. R.; Kelleher, S. M.; Hinton, J.; Parbhoo, S. P.; Thakrar, D. S.; Deery, A.; Crow, J.; Hilson, A. J.W. Author Information

Technetium-99m sestamibi scintimammography has been used primarily in the diagnosis of breast cancer. It has also been suggested that this technique could be used to monitor response to chemotherapy and possibly to predict those patients in whom no response can be expected. An initial study was performed in nine patients with primary breast cancer. All patients underwent prone lateral and anterior99mTc-sestamibi imaging at diagnosis and 4–7 months later, after they had received cytotoxic chemotherapy. The uptake of99mTc-sestamibi in the breast was compared with that in normal surrounding breast tissue and this ratio was expressed as the target to background ratio. In all patients treated there was a reduction in uptake of99mTc-sestamibi after treatment, such that whilst all the tumours could be seen before treatment, only three were visible following chemotherapy. There was a significant fall in the mean target to background ratio of the patients undergoing chemotherapy: the tumour to background ratio was 2.48 before chemotherapy and 1.40 after treatment (P<0.001, paired Student'st test). This fall in tumour activity was observed both in those patients in whom a clinical response was seen and in the two patients in whom the tumour enlarged despite chemotherapy. It appears that the reduced uptake of99mTc-sestamibi seen after chemotherapy may be a non-specific change and therefore may not be predictive of the clinical response to treatment.

Cwikla, J. B.; Buscombe, J. R.; Kelleher, S. M.; Hinton, J.; Parbhoo, S. P.; Thakrar, D. S.; Deery, A.; Crow, J.; Hilson, A. J.W.Author Information

Buscombe, J. R.; Thakrar, D. S.; Hinton, J.; Kelleher, S. M.; Parbhoo, S. P.; Crow, J.; Hilson, A. J.W. Author Information