Identification of the sentinel lymph node in patients with malignant melanoma: what are the reasons for mistakes?

Scintigraphic identification of the sentinel lymph node is achievable in nearly all patients with malignant melanoma. However, in a very small number of cases the sentinel node fails to be detected, and sometimes recurrence appears during follow-up in patients who had previously tested negative for metastatic disease. The purpose of this study was to review our experience in order to isolate the reasons for erroneous sentinel lymph node identification. The evaluation involved 435 consecutive malignant melanoma patients with AJCC stages I and II (clinically negative nodes) and Breslow thickness >0.76 mm. Lymphoscintigraphy was performed the day before surgery by intradermal administration of technetium-99m labelled nanocolloid. Dynamic and static images were obtained. The sentinel node was intraoperatively identified with the aid of patent blue dye and a hand-held gamma probe. After removal, routine histopathological examination with haematoxylin-eosin (H-E) and immunohistochemistry with S 100 and HMB45 (IHC) were performed. In those patients who developed regional recurrences during follow-up, sentinel nodes were further evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). Lymphoscintigraphy visualised at least one sentinel node in 434 out of 435 patients (99.8%). Uptake in in-transit sentinel lymph nodes was observed in 32 patients (7.4%). During surgery, localisation and removal of sentinel nodes was successful in 430/435 patients (98.8%). A total of 790 sentinel lymph nodes were harvested, with a mean of 1.8 per patient. Routine histopathological examination with H-E or IHC revealed metastatic disease in 72 patients (16.8%). During a mean follow-up of 26 months, seven of those patients with a negative sentinel node developed regional lymph node metastases. In five of them RT-PCR was positive for micrometastases within the sentinel node. In conclusion, erroneous sentinel lymph node identification can be due to changes in the surgical team, difficult lymph node location or absence of a thorough histological study. Nevertheless, it is not possible to explain completely why, in a very small percentage of cases, the sentinel node is erroneously identified.

Further data on the usefulness of sentinel lymph node identification and ultrastaging in vulvar squamous cell carcinoma

OBJECTIVE

The aim was to determine the feasibility of surgical identification and pathological ultrastaging of sentinel nodes (SNs) in vulvar carcinoma and to evaluate whether SN negativity rules out the possibility of metastasis in other nodes and can therefore avoid conventional lymphadenectomy.

MATERIAL AND METHODS

In 26 patients with vulvar squamous cell carcinoma the SNs were detected using both peritumoral injection of (99m)Tc and blue dye (isosulfan or methylene) before the surgical procedure. Dissection of the SNs was followed by standard lymphadenectomy and vulvar exeresis. For pathological ultrastaging at least eight histological sections of every node separated 400 microm were evaluated using hematoxylin & eosin and immunostaining against cytokeratin.

RESULTS

We identified the SNs in 25/26 patients (96%). In 19 patients (76%) the SN was unilateral and in 6 (24%) it was bilateral. A total of 46 SNs were isolated. Metastatic carcinoma was identified in 9 SNs from 8 patients (30.8%). Thirty-eight percent (3 of 8) patients with metastatic SNs presented micrometastasis detected only in ultrastaging. Seven (3.3%) of 239 nonsentinel nodes (non-SNs) showed metastasis. No metastatic implant was detected in non-SNs when SNs were negative in patients without clinical suspicious adenopathy (100% negative predictive value).

CONCLUSION

Inguinofemoral lymph nodes can be confidently avoided when sentinel node metastases are excluded by histological ultrastaging. This may reduce the surgical morbidity of conventional inguinofemoral lymphadenectomy, without worsening vulvar cancer prognosis.

Gamma-detecting probe used intraoperatively to locate the sentinel lymph node in patients with malignant melanoma

OBJECTIVE

To assess the usefulness of lymphoscintigraphy and intraoperative gamma probe in the detection of sentinel lymph nodes.

DESIGN

Prospective open study.

SETTING

University hospital, Spain.

SUBJECTS

40 patients with malignant melanoma (24 stage I/II, 16 stage III).

INTERVENTION

The day before operation a lymphoscintigram with 99mTc-nanocolloid was taken and the first lymph node identified was considered to be the sentinel node. A hand-held gamma probe was used for intraoperative mapping.

MAIN OUTCOME MEASURE

Identification of the sentinel node.

RESULTS

Sentinel nodes were identified in 39/40 patients (98%). In 24 patients with stage I/II disease, 34 sentinel nodes were found (6 invaded and 28 clear of melanoma). A total number of 161 regional lymph nodes were harvested, none of them invaded by melanoma. In 16 patients with stage III disease, 22 sentinel nodes were located (14 invaded and 8 clear of melanoma). A total of 89 regional lymph nodes were excised in patients with invaded sentinel nodes (44 of which were invaded and 45 clear of disease). 41 lymph nodes were excised from patients with clear sentinel nodes, and all were also clear of melanoma.

CONCLUSIONS

We conclude that this is a useful technique for the selection of patients with melanoma who may require lymphadenectomy.

Noninvasive assessment of cardiac risk in type I diabetic patients being evaluated for combined pancreas-kidney transplantation using dipyridamole-MIBI perfusion tomographic scintigraphy

This study was performed to determine the value of dipyridamole-99m Tc-methoxy-isobutyl isonitrile perfusion (99mTC-MIBI) tomographic scintigraphy in the assessment of cardiac risk in patients being evaluated prior to combined pancreas-kidney transplantation (PKT). We performed perfusion tomographic scintigraphy using single photon emission computed tomography (SPECT) on 77 patients. The tomographic images did not show clinically relevant findings in 65 patients. In the remaining 12 patients, coronary arteriography was performed: 2 showed normal results, 4 showed no stenosis, and 6 showed significant stenosis ( > or = 70%). Seventy-two patients underwent PKT. During the follow-up (6-48 months), there were seven cardiac events, 4 patients with significant stenosis, and 3 with nonsignificant stenosis upon coronary arteriography, and all had pathological tomographic images. 99mTc-MIBI tomographic scintigraphy may be useful in identifying patients at low risk of incurring cardiac events after PKT and may, in a large group of patients, obviate the need for routine coronary angiography.

Sentinel lymph node biopsy in breast cancer patients: subdermal versus peritumoural radiocolloid injection

BACKGROUND AND AIMS

Sentinel lymph node (SLN) biopsy has been widely used in the management of melanoma and breast cancer. The aims of this study were (1) to compare the results obtained with the two main injection techniques, the peritumoural and subdermal; and (2) to determine the reliability of SLN to predict the regional lymph node status.

METHOD

We prospectively studied 80 women (mean age 56 years) with breast cancer. Thirty-four of them were T1 and the remaining 46 were T2. Patients were divided into two groups. Group A, 36 patients were injected subdermally, surrounding the tumour site. Group B, 44 patients were injected peritumourally guided by ultrasound if non-palpable. Planar images were performed 15 min after the injection and continued until SLN identification. Before surgery, blue dye injection was administered similarly to the radiocolloid. After incision, a hand-held gamma probe was used to reach the SLN. All nodes harvested were analysed by classic pathology techniques.

RESULTS

Overall, lymphoscintigraphy allowed the detection of SLN in 75/80 patients (94%). All subdermal lymphoscintigraphies were positive (36/36) compared with 89% of peritumoural (39/44). Blue dye detected SLN in 23/31 patients (74%) after subdermal injection and in 24/34 patients (71%) after peritumoural injection. The sensitivity to localize the SLN with lymphoscintigraphy+blue dye+gamma probe was 92% (33/36) within the subdermal group and 91% (40/44) within the peritumoural group. Overall, five false negative SLN were found. All of these corresponded to T2 tumours with a size greater than 2.5 cm. The negative predictive value and the accuracy were 93% and 94%, respectively, for the subdermal group and 90% and 93% for the peritumoural group.

CONCLUSIONS

(1) Our results indicate that both techniques have similar results. However, we suggest that T2 tumours with a size greater than 2.5 cm should be excluded from the SLN technique, in order to improve the accuracy and negative predictive value. (2) Lymphoscintigraphy is essential for visualizing the SLN, and blue dye can be helpful when the gamma probe does not localize the SLN.

[Treatment of metastatic bone pain with repeated doses of strontium-89 in patients with prostate neoplasm]

This study has aimed to evaluate the usefulness of repeated treatment with 89Sr in patients with prostate neoplasm and metastatic bone pain. Seventeen patients with partial or complete response after the first dose were retreated with two or more doses (total of 39 doses). The Karnofsky functional status, pain and degree of analgesia were assessed. After the first dose the response was good in 68% of the patients and partial in 32%. After the second dose, the response was good in 62% of the patients, partial in 15% and there was no response in 23% of the cases. The pre-treatment Karnofsky functional status and duration of the effect of 89Sr was lower after the second dose (p = 0.03, p = 0.02), but there were no statistically significant differences in the type of response. In conclusion, re-treatment with 89Sr can be administered safely and with a similar response to that achieved after the first dose.

Usefulness of strontium-89 for bone pain palliation in metastatic breast cancer patients

Most studies of prostate cancer have shown that strontium-89 chloride (89Sr) is effective in the palliation of metastatic bone pain, refractory to conventional analgesia. The aim of this study was to evaluate the usefulness of 89Sr for bone pain palliation in breast cancer patients. Forty women were treated with 148 MBq of 89Sr. Six patients were retreated, receiving two or more doses. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of 89Sr was evaluated at 3 months of treatment. The response was good in 60% of the patients and partial in 32%; there was no response in the remaining 8% (pre-treatment Karnofsky < or = 60). The duration of the response was 120+/-143 days. In the patients retreated, the response was good in 83% and partial in 17%, without significant differences compared with the first dose, but the pre-treatment Karnofsky and the duration of the efficacy were lower (P < 0.05). A transient and slight decrease of leukocyte and platelet counts after the first month of treatment with 59Sr was observed. In conclusion, breast cancer patients with metastatic bone pain can benefit from therapy with 89Sr. If necessary, the treatment may be repeated safely and with the same efficacy as is achieved after the first dose. A low functional performance status could be a cause of the lower effectiveness of 89Sr.

In-111 octreotide scan in a case of a neuroendocrine tumor of unknown origin

Major neuroendocrine tumors contain many somatostatin receptors. This feature allows for the localization of primary tumors and tumor metastases by scintigraphy with the radiolabeled somatostatin analog octreotide. We describe a patient with nonspecific clinical data and ultrasonography and CT that showed an isolated focal lesion in the liver. In-111 octreotide scintigraphy was essential in establishing the diagnosis of liver metastasis from a neuroendocrine tumor confirmed by pathologic findings. Because clinical symptoms recurred, ultrasonography and CT were performed a few months after surgery. Both were negative. However, In-111 octreotide scintigraphy suggested multiple bone metastases and established the diagnosis of bone metastases from a neuroendocrine tumor, which was confirmed by Tc-99m MDP bone scans and MRI.

[111In-pentetreotide in the study of tumors expressing somatostatin receptors]

The usefulness of 111In-pentetreotide scintigraphy in the diagnosis of neuroendocrine tumors was evaluated.

MATERIAL AND METHOD

39 patients with clinical or biochemical suspicion of neuroendocrine tumors were studied. 29 patients underwent surgery and diagnosis was confirmed by anatomopathology findings (7 mixed tumors, 6 carcinoids, 3 insulinomas, 3 pheocromocytomas, 2 glucagonomas, 2 medullary thyroid carcinomas, 1 gastrinoma and 5 metastatic lesions). In 10 patients who did not undergo surgery, the diagnostic criteria were based on a 6 month follow-up. 111In-pentetreotide scintigraphy and computed tomography (CT) were performed in all of the patients.

RESULTS

The scintigraphy correctly detected 58% of the primary tumors while the CT was positive in only 45% of the cases. Both techniques detected metastasis in 5 patients.

CONCLUSION

111In-pentetreotide scintigraphy is a useful technique to diagnose those tumors that have somatostatin receptors. In our series, the sensitivity of this method was higher than the CT.

Quantitative evaluation of bone scintigraphy in the assessment of Paget's disease activity

Interest in the assessment of activity of Paget's disease has increased since the advent of effective therapies. The aim of this study was to develop a quantitative method for the scintigraphic assessment of Paget's disease activity in bone. Twenty patients with Paget's disease were studied prospectively. A scintigraphic visual activity index, together with a quantitative activity index that reflects both the extent and activity of the disease, was obtained for each patient. The quantitative activity index is calculated as the sum of the activity (geometric mean measured from the anterior and posterior views) for all affected bones divided by a reference obtained in non-affected bone. To evaluate the validity of the scintigraphic methods, several biochemical markers of bone turnover were assessed: serum total alkaline phosphatase and serum propeptide aminoterminal of type I procollagen (PINP) as markers of bone formation; urinary hydroxyproline and urinary N-terminal cross-linked telopeptide of type I collagen (NTx) as markers of bone resorption. The visual and quantitative scintigraphic indices were highly correlated (r = 0.78, P < 0.0001). The highest correlations between the biochemical markers and the quantitative activity index were found for PINP (r = 0.69, P < 0.001), which was the most sensitive marker of bone formation, and for urinary NTx (r = 0.63, P < 0.005), which was the most sensitive marker of bone resorption. In conclusion, quantitative evaluation of bone scintigraphy allows easy and objective assessment of Paget's disease activity and it may be useful in evaluating the effectiveness of therapies.

[Myocardial perfusion scintigraphy with 99mTC-sestamibi and gated SPECT and myocardial perfusion scintigraphy with reinjection of 201Tl at 24 hours. Are the techniques comparable?]

AIM

To compare the results obtained with 99mTc-sestamibi and gated-SPECT (gated SPECT in stress and rest) with 201Tl (stress, redistribution, and 24 hour reinjection SPECT).

METHODS

Twenty patients underwent two SPECT studies, one with 201Tl and the other with 99mTc-sestamibi.

RESULTS

Using 201Tl as a reference, 177 segments were considered normal, 31 viable and 32 with myocardial necrosis. The overall concordance with 99mTc-sestamibi was 84.2%. In the subgroup of defects that improved after reinjection of 201Tl, it was much less (45%), even after wall thickness and movement (55%) were analyzed.

CONCLUSION

The overall concordance between 201Tl scintigraphy compared to 99mTc-sestamibi is acceptable. Correlation is low in the viable segments with 99mTc-sestamibi, even after analyzing the Gated-SPECT.

[Sentinel lymph node detection with lymphoscintigraphy and intraoperative probe in malignant melanoma patients]

BACKGROUND

The sentinel lymph node is the first node in a lymphatic basin to receive lymphatic drainage from a tumor site. If this node is free of tumor, then radical lymphadenectomy may be avoided. The goal of this study was to assess the usefulness of lymphoscintigraphy and intraoperative gamma probe in the sentinel node detection in patients with malignant melanoma.

METHOD

We prospectively studied 40 patients with malignant melanoma (24 in I/II stages and 16 in III stage). The day before surgery a lymphoscintigraphy with 99mTc-nanocolloid was performed and the first lymph node identified was considered as sentinel node. For intra-operative mapping a hand-held gamma probe was used.

RESULTS

Sentinel nodes were identified in 39/40 (97.5%) patients. In 24 patients with I/II stages 34 sentinel nodes were demonstrated (six positive and 28 negative for malignant melanoma). A total amount of 161 regional lymph nodes was harvested, all of them being negative for malignant melanoma. In 16 patients with III stage, 22 sentinel nodes were located (14 positive and eight negative for malignant melanoma). A total of 89 regional lymph nodes were excised in sentinel nodes positive patients (44 positive and 45 negative for malignant melanoma) and 36 lymph nodes in sentinel node negative, all of them negative for malignant melanoma.

CONCLUSIONS

In patients with malignant melanoma, lymphoscintigraphy with 99Tc-nanocolloid is useful for the detection of sentinel lymph node. Biopsy of this node is useful for the selection of patients to undertake a lymphadenectomy.

Radioimmunoguided surgery of colorectal carcinoma with an 111In-labelled anti-TAG72 monoclonal antibody

Radioimmunoscintigraphy (RIS) and radioimmunoguided surgery (RIGS) were assessed for their usefulness in patients with colorectal carcinoma. Twenty-nine patients (18 primary tumours, 10 with a suspicion of recurrence and one colonic diverticulitis) were studied. Radioimmunoscintigraphy was performed 48 and 72 h after the injection of an anti-TAG72 monoclonal antibody (CYT-103) labelled with 111In. Radioimmunoguided surgery was performed between 72 and 96 h post-injection. During surgery, a systematic screening was performed with a hand-held gamma detecting probe and a surgical index (tumour-to-normal tissue) was obtained. There were statistically significant differences between counts in normal tissue versus tumour (P < 0.001) and RIGS was considered positive for the detection of tumour if the ratio between the counts in the area suspicious of tumour and the counts in the normal tissue was greater than 1.5. The overall sensitivity for RIS and RIGS was 71.4% (55.6% in primary tumours and 100% in recurrences) and 82.1% (83.3% in primary tumours and 80% in recurrences), respectively. Radioimmunoguided surgery changed the surgical procedure in two cases with small tumour deposits. Occult regional lymph node involvement in primary tumours was not found; therefore, RIGS, as a complementary technique to RIS, is particularly useful in recurrences and can help the surgeon in the resection of small tumour deposits which are difficult to localize.

Predictive value of 99Tcm-sestamibi gated SPET for long-term myocardial perfusion and functional recovery after an acute myocardial infarction

We assessed the predictive value of 99Tcm-sestamibi gated single photon emission tomography (SPET) for changes in perfusion and functional outcome after an acute myocardial infarction and compared the findings on functional recovery with echocardiography using low-dose dobutamine. Gated 99Tcm-sestamibi SPET and radionuclide angiocardiography were performed in 17 patients 4-10 days after an acute myocardial infarction. Six months later, both isotopic studies and rest-dobutamine echocardiography were performed to assess outcome. Perfusion improved in six of seven severely hypoperfused segments (positive predictive value = 85.7%) that showed wall thickening but not in any of 28 segments (negative predictive value = 100%) without wall thickening. The mean ejection fraction improved from 47.7 to 52.3% (P = 0.018). Furthermore, there was a greater improvement in ejection fraction in the group of patients in whom wall thickening predicted a recovery in perfusion (9.0 vs 3.7%, P = 0.01). A comparison of the assessment of functional recovery between gated SPET and dobutamine echocardiography showed good agreement (81.4%). We conclude that the presence of wall thickening in severely hypoperfused segments on 99Tcm-sestamibi gated SPET is predictive of changes in perfusion and functional recovery after acute myocardial infarction, thus identifying the presence of viable myocardium. In contrast, segments showing hypoperfusion and dysfunction after an acute myocardial infarction probably contain scar tissue only.

[Detection of sentinel lymph nodes by lymphatic gammagraphy and intraoperative gamma-ray probe in patients with malignant melanoma. Initial results]

In the last years there has been an arising concern in the sentinel lymph node identification, the first lymph node to receive direct draining from the primary tumour, specially in malignant melanoma (MM). We studied 20 patients with MM: 10 with palpable regional lymph nodes and 10 without palpable LN by performing a lymphoscintigraphy using 99mTc-nanocolloid and a gamma-ray detecting probe during the surgery to locate the sentinel lymph node. In patients with palpable LN, 13 sentinel lymph nodes were identified. Ten of them were MM involved. Furthermore, 82 LN were harvested from involved lymph basins and 30 of them were positive for MM. In patients without palpable LN, 14 sentinel lymph nodes were identified (3 positives and 11 negatives for MM) and other 76 LN were resected (all of them negative). There were not <<skip metastases>> in any patient. These preliminary results support the utility of the technique for the diagnosis and lymphadenectomy selection in patients without palpable LN but which could be involved by micrometastases.

[Evaluation of left ventricular contraction using heart tomography with technetium 99m tetrofosmin in synchrony with ECG. Correlation with bidimensional echocardiography]

BACKGROUND

Echocardiography is a standard method of evaluating segmental and global left ventricular function in clinical practice. The aim of this study was to determine if segmental and global ventricular function determined from Gated SPECT myocardial imaging adequately coincides with echocardiographic data.

PATIENTS AND METHODS

We studied 23 patients with ischemic heart disease referred for clinical 99mTc tetrofosmin Gated SPECT imaging. The results were compared with those obtained using a standard rest echocardiographic assessment. Both studies were performed within a 24-48 hour period. Segmental results in both studies were analyzed by semiquantitative visual scoring using a two or three-point grading system and a summed score was obtained to determine global left ventricular function.

RESULTS

There was a good segmental score agreement between both techniques for wall motion (77.5%; kappa = 0.49) and less for wall thickening (85%; kappa = 0.36). There were non significant statistical differences in the global left ventricular function with both techniques by wall motion (echocardiography 15.3 +/- 5.4 vs tetrofosmin 14.9 +/- 4.4; p = NS) and wall thickening (echocardiography 12.7 +/- 2.3 vs tetrofosmin 12.4 +/- 1.8; p = NS) scores. Correlation for global wall motion (r = 0.81; p < 0.0001) and wall thickening (r = 0.72; p = 0.0001) scores between the two modalities was good.

CONCLUSIONS

Gated SPECT 99mTc tetrofosmin myocardial imaging is a valid method to assess segmental and global left ventricular function and agrees well with echocardiography.

Mid-arm sentinel lymph nodes showing surprising drainage from a malignant melanoma in the forearm

A 51-year-old man with a malignant melanoma in his left forearm was studied to detect the sentinel lymph node and to assess the possibility of micrometastases in regional lymph nodes. Lymphoscintigraphy demonstrated two sentinel lymph nodes in the midarm. Two other nodes in the same location as well as in the left axilla were also observed. The exact location of the sentinel lymph nodes was identified with a gamma-ray detector. At the time of surgery, blue dye was injected around the primary lesion and the two sentinel lymph nodes on the inner side of the left arm were resected. Both lymph nodes were pigmented black. The histopathologic study demonstrated metastases from malignant melanoma in both nodes. This case reflects the main role of lymphoscintigraphy in identifying draining lymph nodes in unusual locations as observed in this patient.

[Anatomopathological bases of latent ventricular dysfunction in insulin-dependent diabetics]

INTRODUCTION AND OBJECTIVES

The natural history of diabetic cardiomyopathy remains unclear, mainly due to concurrent coronary disease or hypertension. Since the presence of confounding factors is less likely in youngsters, they constitute a suitable study model to analyze early stages of diabetic cardiomyopathy.

PATIENTS AND METHODS

We screened 33 young normotensive asymptomatic patients with type I diabetes mellitus. Mean age was 28 +/- 8 y (range 18 to 46 y) and there were 14 men.

RESULTS

2-D Echo showed normal left ventricular size and wall motion in all patients but one. Radionuclide basal ejection fraction was 56.5 +/- 6.6% and increased to 63 +/- 7.4% (p < 0.02) on exercise. According to Rozansky criteria, 16 patients had an abnormal response. Abnormal stress sestamibi was detected in 18 patients and only 3 had reversible defects. Coronary angiography was performed in 11 patients with at least one abnormal non-invasive study response. Coronary angiography revealed normal vessels in all patients and left anterior descending blood flow velocity (Doppler) increased 4 fold after papaverine infusion. Left ventricular biopsies showed hypertrophy (either nuclear or cellular) in 11, myocytolysis in 6, interstitial fibrosis in 9 and lipid deposits in 4. Morphometric analysis of cardiac samples comparing the diabetic group and a control group showed that the volume fraction of fibrosis (0.19 +/- 0.06 vs 0.10 +/- 0.06; p < 0.01), fiber area -mu2- (1,062 +/- 547 vs 600 +/- 167; p < 0.02) and fiber diameter -mu- (24.2 +/- 3.3 vs 15.1 +/- 3.4; p < 0.001) were higher in the former; and volume fraction of the myocytes was higher in the latter (0.71 +/- 0.006 vs 0.89 +/- 0.07; p < 0.001).

CONCLUSIONS

Left ventricular dysfunction, not related to coronary atherosclerosis or small vessel disease, is frequent in asymptomatic young diabetic patients. Abnormal pathologic findings are common in the type of cell hypertrophy, interstitial fibrosis, myocytolysis and lipid deposits.

Preoperative parathyroid gland localization with technetium-99m sestamibi in secondary hyperparathyroidism

Technetium-99m sestamibi scintigraphy has become a valuable tool in locating parathyroid glands in patients with primary hyperparathyroidism. The aim of this study was to evaluate its usefulness in secondary hyperparathyroidism. Twenty patients were injected intravenously with 740 MBq of 99mTc-sestamibi and images were obtained at 15 min and 2 h post injection. All patients underwent parathyroid ultrasonography (US) as well as bilateral surgical neck exploration and 64 parathyroid glands were removed. US revealed at least one enlarged gland in 15/20 patients (75%), while 99mTc-sestamibi scintigraphy showed focal areas of increased uptake in at least one gland in 17/20 patients (85%). When imaging results for all glands were evaluated according to surgical results, sensitivity was 54% for parathyroid scintigraphy and 41% for US, and specificity was 89% for both imaging techniques. There was a discrepancy between the two imaging modalities in 28 glands (35%). The mean surgical weight of US-positive glands (1492+/-1436 mg) was significantly higher than that of US-negative glands (775+/-703 mg) (P<0.05). However, there were no significant differences in weight between sestamibi-positive and sestamibi-negative glands. When only sestamibi-positive glands were considered, a positive correlation between uptake and weight was found (r=0.4, P<0.05). In conclusion, parathyroid US and 99mTc-sestamibi scintigraphy are complementary imaging techniques in the preoperative localization of abnormal parathyroid glands in patients with secondary hyperparathyroidism. The limited sensitivity of the techniques means that patients will still require bilateral neck exploration; therefore routine preoperative parathyroid scanning in renal patients is not justified.

Strontium-89 for palliation of pain from bone metastases in patients with prostate and breast cancer

We have used strontium-89 chloride (89Sr) for the palliative treatment of metastatic bone pain. Seventy-six patients (50 males with prostate carcinoma and 26 females with breast cancer) were treated with 148 MBq of 89Sr. Sixteen patients were retreated, receiving two or three doses; the total number of injected doses was consequently 95. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of 89Sr was evaluated at 3 months of treatment. Three levels of response were considered: good - when there was an increase in the Karnofsky status and a decrease in the pain score (equal to or higher than 4) or analgesic score (equal to or higher than 1); partial - when there was an increase in the Karnofsky status and a decrease in the pain score (2 or 3 points) without significant changes in the analgesic score; no response - if no variation or deterioration in these parameters was observed. In prostate cancer patients, the response was good in 64% of cases and partial in 25%, and there was no response in the remaining 11%. In breast cancer patients, the response was good in 62% of cases and partial in 31%, and there was no response in the remaining 8%. Duration of the response ranged from 3 to 12 months (mean 6 months). In the patients who were retreated the effectiveness was as good as after the first dose of 89Sr. A decrease in the initial leucocyte and platelet counts was observed after the 1st month of treatment, with a gradual partial to complete recovery within 6 months. It is concluded that 89Sr is an effective agent in palliative therapy for metastatic bone pain in patients with prostate or breast carcinoma. If required, retreatment can be administered safely and with the same efficacy as is achieved by the first dose.

67Ga scintigraphy for the evaluation of recurrences and residual masses in patients with lymphoma

67Ga scintigraphy has proven to be of value in the evaluation of patients with lymphoma, especially in their management after treatment. In this study, computed tomography (CT) and 67Ga scans were compared in 53 patients with lymphoma who had previously been treated. Twenty-eight were patients in continuous clinical remission in whom recurrence was suspected. The remaining 25 patients were studied between 1 and 3 months post-treatment to assess a residual mass. The sensitivity for the detection of lymphoma recurrence was 88% for 67Ga, with two false-negative results, and 59% for CT, with seven false-negative results. In the diagnosis of recurrence, the specificity of 67Ga was 100% and that of CT 72%, with three false-positive results. Therapeutic response was assessed in 25 patients and the ability to predict response to treatment resulted in a specificity of 86% for 67Ga and 81% for CT. Treatment failed in four patients, as detected by 67Ga scan, whereas CT did not detect any of these. In the remaining 21 patients who showed good response to treatment, there were three false-positive results for 67Ga and four for CT. 67Ga scintigraphy can detect relapse more accurately and much earlier than CT, as well as diagnose complete remission after treatment. Therefore, 67Ga scintigraphy should be used routinely in monitoring response to treatment in lymphoma.

Scintigraphic evaluation of the severity of inflammation of the joints with 99TCm-HIG in rheumatoid arthritis

A prospective study was carried out to determine the usefulness of 99TCm-human immunoglobulin G (HIG) scintigraphy in the assessment of the severity of joint inflammation. Twenty-four patients with rheumatoid arthritis were studied. The presence or absence of pain and/or swelling was evaluated in 34 joints and a clinical index taking into account the surface area of each joint was calculated. We measured the following biological markers of inflammation activity: erythrocyte sedimentation rate, C-reactive protein, haemoglobin, platelet count, serum levels of IL-6, TNF-alpha and soluble receptors of IL-2. Scintigraphic was performed 4 h after the injection of 740 MBq 99Tcm-HIG. The scans were evaluated by visual and quantitative analysis and the scores in each joint were weighted for joint size. Pathological uptake of the radiopharmaceutical was noted in 46% (24/52) of joints evaluated as painful, 89% (146/164) of swollen joints and 94% (78/83) of both painful and swollen joints. Both the visual and the quantitative scintigraphic indices correlated significantly with the clinical index, the number of painful joints, the number of swollen joints and several biological markers of inflammation. A very high correlation was also found between the visual and the quantitative scintigraphic indices (r = 0.91, P < 0.0001). In conclusion, 99Tcm-HIG scintigraphy is an objective test to detect synovitis and to assess the severity of inflammation. A careful visual analysis of scans is good enough for routine evaluations and computer quantitative analysis should be used when more accurate intra-individual variation is required.