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D J Kwekkeboom

Publications and source records attributed to D J Kwekkeboom.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of [(177)Lu-DOTA(0),Tyr(3)]octreotate and [(177)Lu-DOTA(0),Tyr(3)]octreotide: which peptide is preferable for PRRT?

PURPOSE: Patients with somatostatin receptor subtype 2-positive metastasised neuroendocrine tumours can be treated with [(177)Lu-DOTA(0),Tyr(3)]octreotate. Some use octreotide as the peptide for peptide receptor radionuclide therapy (PRRT). We compared in seven patients [(177)Lu-DOTA(0),Tyr(3)]octreotide ((177)Lu-DOTATOC) and [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-DOTATATE), to see which peptide should be preferred for PRRT with (177)Lu. METHODS: In the same patients, 3,700 MBq (177)Lu-DOTATOC and 3,700 MBq (177)Lu-DOTATATE was administered in separate therapy sessions. Amino acids were co-administered. Whole-body scanning was performed on days 1, 4 and 7 post therapy. Blood and urine samples were collected. We calculated residence times for tumours, spleen and kidneys. RESULTS: All patients had longer residence times in spleen, kidneys and tumours after use of (177)Lu-DOTATATE (p=0.016 in each case). Comparing (177)Lu-DOTATATE with (177)Lu-DOTATOC, the mean residence time ratio was 2.1 for tumour, 1.5 for spleen and 1.4 for kidneys. Dose-limiting factors for PRRT are bone marrow and/or kidney dose. Although the residence time for kidneys was longer when using (177)Lu-DOTATATE, the mean administered dose to tumours would still be advantageous by a factor of 1.5, assuming a fixed maximum kidney dose is reached. Plasma radioactivity after (177)Lu-DOTATATE was comparable to that after (177)Lu-DOTATOC. Urinary excretion of radioactivity was comparable during the first 6 h; thereafter there was a significant advantage for (177)Lu-DOTATOC. CONCLUSION: (177)Lu-DOTATATE had a longer tumour residence time than (177)Lu-DOTATOC. Despite a longer residence time in kidneys after (177)Lu-DOTATATE, tumour dose will always be higher. Therefore, we conclude that the better peptide for PRRT is octreotate.

Adult↗
PubMed2006

Practical aspects of peptide receptor radionuclide therapy with [177Lu][DOTA0, Tyr3]octreotate.

Lutetium-177 is increasingly used in patients for receptor-targeted radionuclide therapy with peptides such as [DOTA0,Tyr3]octreotate. In our therapy facility, we are performing yearly 400 treatments with each 7.4 GBq [177Lu][DOTA0,Tyr3]octreotate. Finger dosimetry data during radiolabeling reveal higher doses on the right hands of right-handed workers with the highest equivalent dose for the middle finger (53+/-12 microSv/GBq). Extrapolating dosimetry data, assuming 400 doses of 7.4 GBq per year performed by 4 workers, result in a mean equivalent dose of 23+/-11 mSv and 14+/-6 mSv for finger top and ring dose, respectively. Preparation of 400 doses will result in an effective dose of 0.5-1.5 mSv per year for these 4 workers. The extra radiation dose for workers during the radiolabeling of these doses thus remains below 10% of the legal annual limits, which is in accordance with the ALARA optimization principle. Based on measurements of the maximal radiation level at 1 m distance (7.5+/-3.6 microSv/h), patients treated with 7.4 GBq [177Lu][DOTA0,Tyr3]octreotate can already leave the therapy facility the next day. As radioactive waste streams are based on the half-lives of the used radionuclides, 177Lu-waste (t1/2=6.7 d) was initially collected along with the 131I-waste (t1/2=8 d). According to both manufacturers' specifications, 177Lu contains less than 0.4 kBq 177mLu/MBq 177Lu (at the end of neutron irradiation), when produced by the [176Lu n, gamma 177Lu] reaction via thermal neutron bombardment of enriched lutetium oxide. Unfortunately, because of the huge amounts of 177Lu used, contaminating 177mLu turned out to prevent the quick discharge of this waste, for some containers even after some years of storage. Therefore, a technique for calibrating 177mLu was developed, simultaneously confirming the manufacturer's specifications on the presence of 177mLu in 177Lu. Subsequently a reliable technique was developed to measure 177mLu in waste containers using a beta/gamma-contamination monitor. It is advised to collect 177mLu/177Lu-waste and certainly high-activity lutetium waste separated from 131I according the regulations in the country of use. Apart from the mentioned waste, excreta from patients are collected in decay tanks, where they are stored for 1-2 months before they are discarded into the general sewer within the overall tolerated discharge limit (150 radiotoxicity equivalents/year for our department).

Body Burden↗
PubMed2005

Neuroendocrine tumors and somatostatin: imaging techniques.

Tumors and metastases bearing the somatostatin receptor subtypes 2 (SSTR2) or SSTR5 can be visualized in vivo after injection of radiolabeled octapeptide somatostatin analogs like 111In-pentetreotide. The sensitivity of 111In-pentetreotide scintigraphy for the detection of carcinoid tumors is 86-95%. The sensitivity of 111In-pentetreotide scintigraphy for the detection of gastrinomas, vasoactive intestinal polypeptide-secreting tumors, and glucagonomas as well as clinically non-functioning lesions is 75-100%. However, for insulinoma this is 50-60%. 111In-pentetreotide scintigraphy generally has a lower detection rate for benign pheochromocytomas than 123I-MIBG scintigraphy, but it can have a complementary role for the staging of malignant pheochromocytomas. It can also be used for the detection of extra-adrenal pheochromocytomas and paragangliomas. Most GH- and TSH-secreting pituitary adenomas can be visualized using 111In-pentetreotide. 111In-pentetreotide scintigraphy is negative in microprolactinomas and ACTH-secreting pituitary microadenomas. 111In-pentetreotide scintigraphy has been successful for the localization of extra-pituitary ACTH-secreting tumors and their metastases, and especially for occult tumors. A large variety of lesions in and around the pituitary region express somatostatin receptors and, therefore, can be visualized by 111In-pentetreotide scintigraphy.

Carcinoid Tumor↗
PubMed2005

Molecular radiotherapy with somatostatin analogs for (neuro-)endocrine tumors.

Peptide receptor radionuclide therapy (PRRT) holds great promise for the future regarding the treatment of various cancers. With the use of radiolabelled peptides, which bind with high affinity to their receptors on cancer cells, it is possible to target the cancer efficiently. In gastroenteropancreatic tumors, radiolabelled somatostatin analog therapy has proven to be effective. Dose-limiting organs are the bone marrow and the kidneys. With the currently used dose schemes and kidney protection, PRRT is relatively safe and serious side-effecs are rare. Which radiolabelled somatostatin analog can be regarded as the most effective therapy cannot be concluded from the available literature. Also, the development of therapy strategies with combinations of different radionuclides and or peptides is of interest as these strategies may provide an increase in therapeutic efficacy in the future.

Humans↗
PubMed2003

Treatment of patients with gastro-entero-pancreatic (GEP) tumours with the novel radiolabelled somatostatin analogue [177Lu-DOTA(0),Tyr3]octreotate.

Medical treatment and chemotherapy are seldom successful in achieving objective tumour reduction in patients with metastatic neuroendocrine tumours. Treatment with the radiolabelled somatostatin analogue [(90)Y-DOTA(0),Tyr(3)]octreotide may result in partial remissions in 10-25% of patients. The newer analogue [DOTA(0),Tyr(3)]octreotate (octreotate) has a ninefold higher affinity for the somatostatin receptor subtype 2 as compared with [DOTA(0),Tyr(3)]octreotide. Also, labelled with the beta- and gamma-emitting radionuclide (177)Lu, it has proved very successful in achieving tumour regression in animal models. The effects of (177)Lu-octreotate therapy were studied in 35 patients with neuroendocrine gastro-entero-pancreatic (GEP) tumours who underwent follow-up for 3-6 months after receiving their final dose. Patients were treated with doses of 100, 150 or 200 mCi (177)Lu-octreotate, to a final cumulative dose of 600-800 mCi, with treatment intervals of 6-9 weeks. Nausea and vomiting within the first 24 h after administration were present in 30% and 14% of the administrations, respectively. WHO toxicity grade 3 anaemia, leucocytopenia and thrombocytopenia occurred after 0%, 1% and 1% of the administrations, respectively. Serum creatinine and creatinine clearance did not change significantly. The effects of the therapy on tumour size were evaluable in 34 patients. Three months after the final administration, complete remission was found in one patient (3%), partial remission in 12 (35%), stable disease in 14 (41%) and progressive disease in seven (21%), including three patients who died during the treatment period. Tumour response was positively correlated with a high uptake on the octreoscan, limited hepatic tumour mass and a high Karnofsky Performance Score. Because of the limited efficacy of alternative therapies, many physicians currently adopt an expectant attitude when dealing with patients with metastatic GEP tumours. However, in view of the high success rate of therapy with (177)Lu-octreotate and the absence of serious side-effects, we advocate its use in patients with GEP tumours without waiting for tumour progression.

Abdominal Pain↗
PubMed2001

Somatostatin receptor scintigraphy in the follow-up of patients with differentiated thyroid cancer.

UNLABELLED: The aim of this study was to compare the results of somatostatin receptor scintigraphy (SRS) and of radioiodine scintigraphy in patients with metastatic differentiated thyroid carcinoma during L-thyroxine suppression therapy and after withdrawal. Twenty-five patients were studied: 16 patients had papillary cancer and 12 of them had metastatic disease; 9 patients had follicular cancer and 7 of these had known metastases. In 7 patients SRS was performed during thyroxine withdrawal, in 12 during thyroxine therapy within 9 months from radioiodine scintigraphy, in 6 others both during suppression therapy and after withdrawal. SRS was positive in 18 of 25 (72%) patients. It demonstrated lesions in 11 of 13 (85%) patients after thyroxine withdrawal and in 12 of 18 (67%) patients during thyroxine suppression. In 6 patients in whom a direct comparison was made before and after withdrawal, essentially the same information was obtained. Six of 8 (75%) patients with lesions that did not concentrate radioiodine showed uptake of labeled octreotide in these lesions. In 5 of 17 (29%) patients whose tumors concentrated radioiodine, no uptake was found during SRS. CONCLUSIONS: 1) in patients with metastatic differentiated thyroid carcinoma, tumor sites can be visualized using SRS; 2) there is no need to withdraw patients from suppression therapy in order to perform SRS; 3) in some patients whose lesions do concentrate labeled octreotide but not radioiodine, the use of somatostatin analogues labeled with (111)In or [90Y] can provide new therapeutic options.

Adenocarcinoma, Follicular↗
PubMed2001

Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives.

In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, "new" radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy.

Humans↗
PubMed2001

[177Lu-DOTAOTyr3]octreotate: comparison with [111In-DTPAo]octreotide in patients.

The somatostatin analogue [DOTA0,Tyr3]octreotate has a nine-fold higher affinity for the somatostatin receptor subtype 2 as compared with [DOTA0, Tyr3]octreotide. Also, labelled with the beta- and gamma-emitting radionuclide lutetium-177, this compound has been shown to have a very favourable impact on tumour regression and animal survival in a rat model. Because of these reported advantages over the analogues currently used for somatostatin receptor-mediated radiotherapy, we decided to compare [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate) with [111In-DTPA0]octreotide (111In-octreotide) in six patients with somatostatin receptor-positive tumours. Plasma radioactivity after 177Lu-octreotate expressed as a percentage of the injected dose was comparable with that after 111In-octreotide. Urinary excretion of radioactivity was significantly lower than after 111In-octreotide, averaging 64% after 24 h. The uptake after 24 h, expressed as a percentage of the injected dose of 177Lu-octreotate, was comparable to that after 111In-octreotide for kidneys, spleen and liver, but was three- to fourfold higher for four of five tumours. The spleen and kidneys received the highest absorbed doses. The doses to the kidneys were reduced by a mean of 47% after co-infusion of amino acids. It is concluded that in comparison with the radionuclide-coupled somatostatin analogues that are currently available for somatostatin receptor-mediated radiotherapy, 177Lu-octreotate potentially represents an important improvement. Higher absorbed doses can be achieved to most tumours, with about equal doses to potentially dose-limiting organs; furthermore, the lower tissue penetration range of 177Lu as compared with 90Y may be especially important for small tumours.

Adolescent↗
PubMed2001

[(123)I]metaiodobenzylguanidine and [(111)In]octreotide uptake in begnign and malignant pheochromocytomas.

Selecting the appropriate approach for resection and follow-up of pheochromocytomas (PCCs) is highly dependent upon reliable localization and exclusion of multifocal, bilateral, or metastatic disease. Metaiodobenzylguanidine (MIBG) scintigraphy was developed for functional localization of catecholamine-secreting tissues. Somatostatin receptor imaging (SRI) has a high sensitivity for localizing head and neck paragangliomas, but studies of intraabdominal PCCs are rare. In this study we review our experience of [(123)I]MIBG and SRI, performed since 1983 and 1989, respectively, in the work-up of primary and recurrent PCCs. Scintigraphic results were correlated with catecholamine secretion, size and site, malignancy, associated tumor syndromes, and morphological features. [(123)I]MIBG scans were performed in a total of 75 patients, in 70 cases before resection of primary PCCs and in 5 cases because of recurrent disease. Ninety-one PCCs were resected. The overall detection rates were 83.3% and 89.8% for PCCs larger than 1.0 cm. Multifocal disease was detected in 4 patients with [(123)I]MIBG. [(123)I]MIBG uptake correlated with greater size of PCC (r = 0.33; P = 0.008) and greater concentration of plasma epinephrine (r = 0.32; P = 0.006). [(123)I]MIBG-negative PCCs (n = 14) had significantly (P = 0.01) smaller diameters than [(123I)]MIBG-positive tumors. Furthermore, [(123)I]MIBG uptake was significantly higher in unilateral (P = 0.02), benign (P = 0.02), sporadic (P = 0.02), intraadrenal (P = 0.02), and capsular invasive (P = 0.03) PCCs than in bilateral, malignant, MEN2A/2B-related, extraadrenal, and noninvasive PCCs, respectively. The detection rate of SRI was only 25% (8 of 32) for primary benign PCCs. In 14 patients metastases occurred, which were effectively visualized with [(123)I]MIBG in 8 of 14 cases. SRI was able to detect metastases in 7 of 8 cases, including 3 [(123)I]MIBG-negative metastatic cases. In addition, [(123)I]MIBG and SRI detected 2 recurrences. In conclusion, [(123)I]MIBG uptake is correlated with the size, epinephrine production, and site of PCCs. Its role in bilateral and MEN2A/2B-related PCCs seems limited. In cases of recurrent elevation of catecholamines, localization of metastases and/or recurrence should be attempted with [(123)I]MIBG scintigraphy. In suspicious metastatic PCCs, SRI might be considered to supplement [(123)I]MIBG scintigraphy.

3-Iodobenzylguanidine↗
PubMed2000

The role of radioactive somatostatin and its analogues in the control of tumor growth.

Peptide receptor scintigraphy with the radioactive somatostatin analogue [111In-DTPA-D-Phe1]octreotide is a sensitive and specific technique to show in vivo the presence and abundance of somatostatin receptors on various tumors. With this technique primary tumors and metastases of neuroendocrine cancers as well as of many other cancer types can be localized. This technique is currently used to assess the possibility of peptide receptor radionuclide therapy with repeated administration of high doses of [111In-DTPA-D-Phe1]octreotide. 111In emits Auger and conversion electrons, having a tissue penetration of 0.02-10 microns and 200-500 microns, respectively. Thirty end-stage patients with mostly neuroendocrine progressing tumors were treated with [111In-DTPA-D-Phe1]octreotide, up to a maximal cumulative patient dose of about 74 GBq, in a phase-I trial. There were no major clinical side effects after up to 2 years of treatment, except that in a few patients a transient decline in platelet counts and lymphocyte subsets occurred. Promising beneficial effects on clinical symptoms, hormone production, and tumor proliferation were found. Of the 21 patients who received a cumulative dose of more than 20 GBq, eight showed stabilization of disease and six others a reduction in tumor size. There is a tendency towards better results in patients whose tumors have a higher accumulation of the radioligand. Peptide receptor radionuclide therapy is also feasible with 111In as the radionuclide. Theoretically, depending on the homogeneity of distribution of tumor cells expressing peptide receptors and the size of the tumor, beta-emitting radionuclides, e.g., 90Y, labeled to DOTA-chelated peptides may be more effective than 111In for peptide receptor radionuclide therapy. The first peptide receptor radionuclide therapy trials with [90Y-DOTA-Tyr3]octreotide started recently.

Cell Division↗
PubMed2000

Cholecystokinin receptor imaging using an octapeptide DTPA-CCK analogue in patients with medullary thyroid carcinoma.

UNLABELLED: Cholecystokinin (CCK)-B receptors have been demonstrated on a high percentage of medullary thyroid carcinomas (MTC) in vitro. After encouraging results both in vitro and in animal studies, we studied the efficacy of an octapeptide [111In-DTPA]-CCK analogue in seven patients with MTC. In four of five patients in whom serum calcitonin levels were monitored, a significant rise was found following the injection, indicating retained biological activity of the radiopeptide. In all patients there was visualization of the CCK-B receptor-positive stomach. In one of two patients with known MTC lesions, some of the lesions were visualized; in addition some lesions were visualized in one of the five other patients who had elevated serum tumour markers but negative localizing studies. Radioactivity in the presumed tumour sites was still present at 48 h p.i. The uptake in the presumed tumour sites and stomach was low. Background radioactivity dropped rapidly owing to urinary excretion. After 1 h, breakdown products of the labelled analogue predominated both in urine and in serum, and virtually no intact peptide was present. IN CONCLUSION: (1) the CCK-B receptor-positive gastric mucosa and presumed MTC lesions could be visualized in patients using an octapeptide [111In-DTPA]-CCK analogue that is probably internalized, proving the feasibility of CCK-B receptor imaging in vivo; (2) there was a relatively low uptake of the CCK analogue in the strongly CCK receptor positive stomach, and rapid degradation of the peptide in serum.

Carcinoma, Medullary↗
PubMed2000

Adult hyperinsulinemic hypoglycemia not caused by an insulinoma: a report of two cases.

Nesidioblastosis is rare in adults and accounts for 0.5-5% of cases of organic hyperinsulinemia. The diagnosis of nesidioblastosis should be considered when peroperative imaging modalities fail to localize a lesion in patients with hyperinsulinism. Two female patients, aged 55 and 16 years, with hyperinsulinemic hypoglycemia are reported. Somatostatin receptor scintigraphy showed slight focal activity in both patients. The first patient underwent a Whipple procedure and became diabetic. The second patient underwent a distal hemi-pancreatectomy and suffered from recurrent hypoglycemic episodes 3 months after surgery, for which she is presently being treated with octreotide. Histological examination of the resected pancreata revealed focally increased islet tissue and a number of slightly hypertrophic beta cells. Such histological abnormalities have been related to functional changes of beta-cells. In infantile nesidioblastosis, a proportion of cases has been associated with mutations in one of several genes. Whether such mutations, leading to hyperinsulinism, also play a role in adult nesidioblastosis is presently unknown.

Adolescent↗
PubMed2000

Inflammatory pseudotumor of the fossa pterygopalatina: diagnosis and treatment.

Pseudotumor is a term used to describe a space-occupying inflammatory lesion of unknown etiology that clinically simulates a neoplastic process. Pseudotumors of the fossa pterygopalatina and fossa infratemporalis are very rare. In this paper, we describe a patient who developed a pseudotumor in the left fossa pterygopalatina, secondary to an unclassified autoimmune disease, which caused progressive left-sided facialdynia and swelling. The tumor was detected with somatostatin receptor scintigraphy. The lesion was refractory to steroids, also in combination with azathioprine, as well as to surgical intervention. An excellent clinical response was observed after cyclosporine was added. This case is presented here in order to draw attention to the use of somatostatin receptor scintigraphy as a diagnostic tool in visualizing pseudotumors and to document a case that responded excellently to treatment with a combination of low-dose cyclosporine and steroids.

Bone Diseases↗
PubMed2000

Tc-99m sestamibi before and during treatment in a patient with sarcoidosis and persistent hyperparathyroidism.

PURPOSE: Tc-99m sestamibi (MIBI) uptake in pulmonary sarcoidosis has been reported, but it has never been studied before and during treatment with glucocorticoids. METHODS: The authors performed MIBI scintigraphy and somatostatin receptor scintigraphy in a patient with sarcoidosis of the mediastinum, lungs, and liver and who had persistent hyperparathyroidism after unsuccessful neck exploration. RESULTS: Somatostatin receptor scintigraphy showed high mediastinal and pulmonary uptake in a pattern characteristic of sarcoidosis. Sustained MIBI uptake occurred in the same, although smaller, region. After the diagnosis was confirmed by liver biopsy, the patient was treated with glucocorticoids. Repeated MIBI scintigraphy showed that the uptake in the mediastinum had clearly decreased. CONCLUSIONS: This decrease of MIBI uptake in the mediastinal lymph nodes with therapy may imply that MIBI can be used to assess the response to treatment in sarcoidosis. Perhaps a relation exists between MIBI uptake at the moment of diagnosis and prognosis. Further studies in more patients are needed to evaluate the role of MIBI in the management of sarcoidosis.

Diagnosis, Differential↗
PubMed2000

Somatostatin receptor subtypes in human thymoma and inhibition of cell proliferation by octreotide in vitro.

Somatostatin (SS) and SS receptor (SSR) subtypes, code-named sst1-5, are heterogeneously expressed in the normal human thymus. This suggests their involvement in controlling the immune and/or neuroendocrine functions in this organ. Moreover, recently a high in vivo uptake of [111In-DTPA-D-Phe1]octreotide has been reported in patients bearing thymoma. The present study characterizes in vivo and in vitro, functional SS-binding sites in a human thymoma. A high uptake of [111In-DTPA-D-Phe1]octreotide was observed in the chest of a patient with myasthenia gravis due to a cortical thymoma. Specific binding of [125I-Tyr11] SS-14 was found on a membrane preparation of the surgically removed thymoma. Scatchard analysis showed high affinity binding sites (Kd, 47.5 +/- 2.5 pmol/L) with low maximum binding capacity (23.5 +/- 2.5 fmol/mg membrane protein). RT-PCR analysis showed the presence of sst1, sst2A, and a predominant sst3 messenger RNA (mRNA) expression in the tumor tissue. Primary cultured tumor cells expressed sst3 mRNA only. In contrast to the normal thymus, SS mRNA was not expressed. By immunohistochemistry, the tumor cells highly expressed sst3 receptors, weakly expressed sst1 receptors, and showed no immunostaining for sst2A receptors. sst2A immunoreactivity was found in the stromal compartment of the tumor, particularly on the endothelium of small intratumoral blood vessels. In primary cultured tumor cells, both SS and octreotide (10 nmol/L) significantly inhibited [3H]thymidine incorporation by 40.6% and 43.2%, respectively. The following conclusions were reached. 1) As this tumor displayed a high immunoreactivity for sst3 and the cultured tumor cells expressed the sst3 mRNA only, this SSR may be the subtype involved in the inhibition of epithelial tumor cell proliferation by octreotide in vitro. 2) A loss of endogenous SS production in this thymoma might be implicated in the uncontrolled cell growth. 3) In this case, the sst3 may play a role in determining the uptake of [111In-DTPA-D-Phe1]octreotide by in vivo SS receptor scintigraphy.

Antineoplastic Agents, Hormonal↗
PubMed2000

Long-term treatment with the dopamine agonist quinagolide of patients with clinically non-functioning pituitary adenoma.

OBJECTIVE: This study was performed to evaluate the effect of prolonged treatment with the dopamine agonist quinagolide on serum gonadotropin and alpha-subunit concentrations and tumor volume in patients with clinically non-functioning pituitary adenomas (CNPA). DESIGN: Ten patients with CNPA were treated with quinagolide (0.3 mg daily). The median duration of treatment was 57 months (range 36-93 months). Blood samples for measurement of serum gonadotropin and alpha-subunit concentrations were drawn before treatment, after 5 days, and at each outpatient visit. Computerized tomography or magnetic resonance imaging of the pituitary region and Goldmann perimetry were done before and at regular intervals during treatment. RESULTS: A significant decrease of serum FSH, LH or alpha-subunit concentrations was found in nine patients. The levels remained low during the entire treatment period. In two out of three patients with pre-existing visual field defects a slight improvement was shown during the first months of treatment, but eventually deterioration occurred in all three patients. A fourth patient developed unilateral ophthalmoplegia during treatment. During the first year tumor volume decreased in three patients, but in two of them regrowth occurred after a few months. In six patients progressive tumor growth occurred despite sustained suppression of gonadotropin or alpha-subunit levels. CONCLUSIONS: Long-term treatment of patients with CNPA with high doses of the dopamine agonist quinagolide could not prevent progressive increase in tumor size in most patients. It remains unproven whether quinagolide retards CNPA growth. Additional studies are needed to investigate whether subgroups of patients, e.g. those with positive dopamine receptor scintigraphy or those with marked hypersecretion of intact gonadotropins or subunits, will respond more favorably to treatment with dopamine agonists.

Adenoma↗