MR imaging of pituitary macroadenomas before and after transsphenoidal surgery

Hald, John; Nakstad, P; Kollevold, T; Bakke, Søren Jacob; Skalpe, I. O.

doi:10.1080/02841859209172020

Cited by 5 publications

(2 citation statements)

References 12 publications

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“…Earlier investigators have described the problems and pitfalls of interpretation of post-operative MR images (22)(23)(24)(25)(26). Non-identical sequences and sections, varying magnifications, contrast or gray scales, and postoperative artefacts impede the comparison of residual tumor size and volume.…”

Section: Discussionmentioning

confidence: 99%

Pituitary tumor size in acromegaly during pegvisomant treatment: experience from MR re-evaluations of the German Pegvisomant Observational Study

Buchfelder

Weigel²,

Droste³

et al. 2009

European Journal of Endocrinology

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In treatment-resistant patients with acromegaly, pharmacotherapy with pegvisomant (Somavert) is a highly effective option. However, safety concerns have been raised related to a potential increase in tumor size during long-term pegvisomant treatment. Therefore, neuroradiological monitoring of tumor extension and volume was performed in the German Pegvisomant Observational Study, which covers 87% of patients treated with pegvisomant in Germany. As of 15 July 2007, a total of 307 patients (156 males and 151 females) had been included in the study and were on pegvisomant therapy for an average of 86.7 weeks. Median and mean doses of pegvisomant were 15 and 16.6 mg/day respectively. Out of these 307 patients, 18 were reported to have tumor-size increases as adverse events. From these 18 patients, all available serial magnetic resonance images were collected. Identical or similar sequences were chosen and the region of interest was magnified and compared across time after the best possible fit had been achieved by size and gray-scale correction. All available images were carefully re-evaluated according to this method. In 10 out of the 18 patients, there was no evidence of tumor-size increase, when the pre-treatment scans were compared with the most recent follow-up investigations. In two out of the remaining eight patients, there was a rebound effect observed after withdrawal of somatostatin analog treatment, but no further progression. In another three out of the eight patients, tumor-size increase had already been documented before pegvisomant treatment was commenced, during preceding somatostatin analog treatment and continued therapy. In the last three patients, tumor progression after the start of pegvisomant treatment was confirmed. All three patients had undergone pituitary surgery as primary treatment, but had not been pre-treated with radiotherapy. In all three cases, the tumor increase was not considered clinically significant and the investigators decided to continue pegvisomant treatment. In conclusion, in this large group of pegvisomant-treated patients, tumor progression was rare. It was reported in between 2 and 3% of patients treated, and did not exceed the expected rate in patients with acromegaly not treated with pegvisomant. In over one-half of patients, reports of tumor increase could not be confirmed by re-evaluation. This was mostly due to non-identical gantry projections. Misjudgements mainly occurred when only images from two individual investigations, rather than the entire series of scans, were compared. Thus, we recommend a careful serial evaluation of all available images to avoid misinterpretations and erroneous alerts. As from this presently largest database of acromegalic patients treated with pegvisomant, tumor-growth rate appears not to be different from patients on other treatment modalities. Although these data are reassuring with regard to the concern of somatotroph adenoma growth under peripheral GH receptor blockade, further study is required.

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Section: Discussionmentioning

confidence: 99%

Pituitary tumor size in acromegaly during pegvisomant treatment: experience from MR re-evaluations of the German Pegvisomant Observational Study

Buchfelder

Weigel²,

Droste³

et al. 2009

European Journal of Endocrinology

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“…Quest'ultimo presenta a sua volta, in genere, un potenziamento di segnale lento e tardivo: questo differente comportamento dopo somministrazione di mezzo di contrasto paramagnetico risulta enfatizzato in corso di esame RM dinamico eseguito durante iniezione endovenosa di mdc (figure 2, 4) , che consente di aumentare l'accuratezza diagnostica della indagine RM stessa 7 Un iposegnale T2 specie in echo di gradiente e espressione di deposita di emosiderina postemorragica, di eventuali calcificazioni o di artefatti da esiti postchirurgici 17 • In presenza di un quadro T1 di base incerto o apparentemente negativo, specie nel contesto di un quadro clinico e ormonale comunque sospetto per microadenoma, e utile ricorrere sistematicamente alle scansioni TSE T2 alla ricerca di un'eventuale alterazione focale del segnale intraparenchimale che possa indirizzare la diagnosi prima di procedere alle scansioni T1 con contrasto: l'uso combinato pertanto di sequenze T2 e T1 e preferibile data la complementarieta delle due sequenze (figura 5).…”

Section: Segni Diretti DI Microadenoma Ipofisario: Caratteristiche Deunclassified

Microadenomi ipofisari: Aspetti RM

Calabrò

Michelozzi

Schiavoni

et al. 2000

Rivista di Neuroradiologia

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RIA SSUNTO -La RM per le sue caratteristiche specifiche ed uniche ha sostituito la TC nello studio della patologia ipofisaria in genere e dei microadenomi in particolare. La RM consente infatti nella pressoche totalita dei casi di accertare la presenza di un microadenoma di cui inoltre ne consente un agevole monitoraggio in corso di terapia medica e dopo terapia chirurgica.La diagnostica RM dei microadenomi si avvale dell'impiego combinato di sequenze T2 e Tl prima e dopo mdc e di sequenze dinamiche in corso di iniezione di mdc: l'accertamento di microadenoma e in funzione della presenza di segni RM diretti ed indiretti. Nei rari casi per i quali la diagnostica RM non consente una diagnosi sicura e specie se esiste il sospetto di adenomi a secrezione ACTH e indicato il ricorso al cateterismo dei seni petrosi. La TC potrebbe essere utilizzata esclusivamente nei casi che per differenti ragioni non possono giovarsi dell'impiego della RM. Pituitary Microadenomas: MR FeaturesSUMMARY -Pituitary tumours constitute about 10-15% of intracranial tumours. Neuroradiologically, they are termed microadenomas when their diameter is less than 10 mm and macroadenomas when larger. Adenoma cell differentiation affects the immunohistochemical features of adenomas permitting a distinction between functional secreting adenomas and non-functioning adenomas. Overall, microadenomas secreting prolactin are the most common, followed by non-functioning tumours, adenomas secreting GH, those with mixed secretion, tumours secreting ACTH and lastly, rare TSH-secreting adenomas. In almost all cases they are benign tumours, even though there is a tendency towards local invasion. Malignancy and metastases are exceptional. MR has replaced CT in the study of microadenomas as in most cases it will identify the tumour directly as a small signal abnormality and indirectly through the effects on the healthy pituitary gland and its stalk. MR is usually performed combining T2 and T1 weighted scans and dynamic techniques during injection of contrast administration at normal or reduced doses .In general, microadenomas are depicted in T1 scans as a signal hypointensity accentuating during and after contrast injection. However, microadenomas largely isointense to the pituitary parenchyma, microadenomas spontaneously hyperintense if bleeding and microadenomas hyperintense soon after contrast administration are also encountered. In T2 sequences, spontaneous, often heterogeneous, hyperintensity of the microadenoma is often seen. The main indirect signs of a microadenoma include erosion of the sellar floor, raised superior pituitary profile and changes in the medial profile of the cavernous sinus on the side of the microadenoma as well as displacement of the pituitary stalk contralateral to the adenoma site. Without direct signs, indirect signs alone preclude final diagnosis of microadenoma. Differential diagnosis of microadenomas includes intermediate cysts, Rathke's cleft cysts and intrasellar craniopharyngioma. Benign aspecific focal signal abnormalities in th...

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Improving postoperative MR imaging of pituitary macroadenomas: comparison of full and reduced dose of gadopentetate dimeglumine

Hald¹,

Eldevik

Dunn

et al. 2000

European Radiology

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The aim of this study was to evaluate the efficacy of contrast-medium (CM)-ehanced MR imaging of operated pituitary macroadenomas with reduced dose of gadopentetate dimeglumine. In a prospective study 18 patients were examined with coronal T1-weighted MR imaging prior to and following intravenous CM injections. Two sets of contrast-enhanced coronal images were obtained in each patient; the first set after 50% of the recommended dose of 0.1 mmol/kg body weight (b.w.) had been administered, and the second set immediately after additional CM had been given to make up a total dose of 0.1 mmol/kg b.w. The images were evaluated by three neuroradiologists. The SIPAP classification system was used to evaluate tumour extension, whereas tumour margin conspicuity was scored using an arbitrary scale of 1-5 (1 = indistinct, 5 = well defined). Signal intensity measurements obtained from the most enhancing part of the adenomas demonstrated increased enhancement with increased CM dose. Tumour delineation scores were significantly better on the reduced- and full-dose images than on pre-CM injection images, but, with one exception, tumour extension was identified as the same on all imaging sequences. Postoperative MR imaging of large macroadenoma residues can routinely be performed without intravenous CM. When CM is indicated a reduced dose of gadopentetate dimeglumine should provide sufficient diagnostic information.

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MR imaging of pituitary macroadenomas before and after transsphenoidal surgery

Cited by 5 publications

References 12 publications

Pituitary tumor size in acromegaly during pegvisomant treatment: experience from MR re-evaluations of the German Pegvisomant Observational Study

Pituitary tumor size in acromegaly during pegvisomant treatment: experience from MR re-evaluations of the German Pegvisomant Observational Study

Microadenomi ipofisari: Aspetti RM

Improving postoperative MR imaging of pituitary macroadenomas: comparison of full and reduced dose of gadopentetate dimeglumine

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