Evaluation of MRI Criteria for Cavernous Sinus Invasion in Pituitary Macroadenoma

Predicting the Consistency of Pituitary Macroadenomas: The Utility of Diffusion-Weighted Imaging and Apparent Diffusion Coefficient Measurements for Surgical Planning

Understanding the consistency of pituitary macroadenomas is crucial for neurosurgeons planning surgery. This retrospective study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) as non-invasive imaging modalities for predicting the consistency of pituitary macroadenomas. This could contribute to appropriate surgical planning and therefore reduce the likelihood of incomplete resections. The study included 45 patients with pathologically confirmed pituitary macroadenomas. Conventional MRI sequences, DWIs, ADC maps, and pre- and post-contrast MRIs were performed. Two neuroradiologists assessed all of the images. Neurosurgeons assessed the consistency of the tumor macroscopically, and histopathologists examined it microscopically. The MRI findings were compared with postoperative data. According to the operative data, macroadenomas were divided into the two following categories based on their consistency: aspirable (n = 27) and non-aspirable tumors (n = 18). A statistically significant difference in DWI findings was found when comparing macroadenomas of different consistencies (p < 0.001). Most aspirable macroadenomas (66.7%) were hyperintense according to DWI and hypointense on ADC maps, whereas most non-aspirable macroadenomas (83.3%) were hypointense for DWI and hyperintense on ADC maps. At a cut-off value of 0.63 × 10-3 mm2/s, the ADC showed a sensitivity of 85.7% and a specificity of 75% for the detection of non-aspirable macroadenomas (AUC, 0.946). The study concluded that DWI should be routinely performed in conjunction with ADC measurements in the preoperative evaluation of pituitary macroadenomas. This approach may aid in surgical planning, ensure that appropriate techniques are utilized, and reduce the risk of incomplete resection.

Magnetic resonance imaging characteristics of residual pituitary tissues following transsphenoidal resection of pituitary macroadenomas

Objective

The present study is to investigate the pre- and post-operative magnetic resonance imaging of pituitary tissues following transsphenoidal resection of pituitary macroadenomas, as well as its clinical significance.

Materials and Methods

The medical records of 108 consecutive pituitary macroadenoma patients admitted at Fuzhou 900th Hospital between September 2012 and September 2014 were retrospectively reviewed. Siemens 3. 0T magnetic resonance scanner was used to perform pre- and postoperative MRI scanning, including plain scan and contrast-enhanced scan of SE sequential T1WI and T2WI in sagittal, coronal and axial views. PACS medical imaging system was used to measure the diameter of pituitary adenoma, as well as the volumes of the adenoma and pituitary tissue. Hematoxylin-eosin staining and immunohistochemical staining were also performed.

Results

Higher height of pituitary adenoma results in lower rate of posterior pituitary bright spot (PPBS) on MR T1-weighted imaging. Preoperative MR signal intensity of PPBS was negatively related to diabetes insipidus (DI). Normal pituitary tissues were likely to be above the pituitary adenomas in growth hormone-secreting adenoma patients, while mostly located aside in gonadotropin-secreting adenoma patients. Morphological restitution of postoperative pituitary tissues was better in lateral displacement than that in superior or superolateral patterns on pre-operative MR images. Positive rate of PPBS on preoperative MRI is negatively related to adenoma height, and the signal intensity of PPBS is inversely related to postoperative DI.

Conclusions

The relative locations of pituitary tissues and adenoma tissues may be associated with the adenoma type and may affect the postoperative remodeling of residual pituitary tissues.

Assessment of magnetic resonance imaging criteria for the diagnosis of cavernous sinus invasion by pituitary tumors

Cavernous sinus invasion (CSI) by pituitary tumors is associated with subtotal resection and persistent endocrinopathy. The Knosp classification is a magnetic resonance imaging (MRI) tool used to define CSI in the 2017 World Health Organization Classification. However, alternative criteria may have superior diagnostic performance. This study aimed to assess the diagnostic performance of four MRI criteria, using a combination of endoscopy and day 1 MRI as the reference standard for CSI. A cross-sectional study was conducted including patients treated with endoscopic endonasal transsphenoidal surgery for pituitary macroadenomas, recruited from a tertiary pituitary multidisciplinary center in Sydney, Australia between September 2013, and February 2021. The diagnostic performances of four MRI criteria were assessed: the Knosp criteria, percentage encasement of the internal carotid (PEICA), venous compartment obliteration (VCO), and the Fernandez-Miranda classification. Reference CSI was defined using a combination of intraoperative endoscopy and day 1 MRI. A total of 210 cavernous sinuses (105 patients), were analyzed, (51.7 ± 16.3yrs, 43% female), of which 18% had CSI. CSI was best diagnosed by Knosp ≥ 2 (63% sensitivity and 89% specificity), PEICA ≥ 28% (84% sensitivity and 77% specificity) and VCO of ≥ 3 compartments (65% sensitivity and 89% specificity). CSI was unlikely if any of the following signs were present: Knosp < 1, PEICA < 28%, preservation of the medial or superior compartments or sparing of the superior Fernandez-Miranda compartment (negative predictive value 95%, 95%, 94%, 91% and 92% respectively). In conclusion, alternatives to the Knops criteria including PEICA and VCO can aid CSI diagnosis.

Inadvertent internal carotid artery (ICA) injury during transsphenoidal surgery: review of literature

Background

Internal carotid artery (ICA) injury is a hazardous catastrophe for the skull base surgery team. We aimed to illustrate the vital joints in this hazardous event during endoscopic surgery.

Main text

The condition is rare (1.1%) but fatal per se. Working in the field of endoscopic surgery is not free of charges. It demands a thorough knowledge of anatomy, variations, and pathoanatomy to expect what can be seen thereafter. Once the injury occurs, one must have a quite clear plan to proceed. Marvelous bleeding is confusing not only in the field but also in the mind process.

Conclusion

Endoscope teams when expose to this event should think in a stepwise manner. In our review, we explained the pathoanatomy of the field after an injury, pre-conditions of injury, and how to avoid certain drawbacks during management.

Neuroimaging of aggressive pituitary tumors

Aggresssive pituitary tumors are defined as radiologically invasive, exhibiting a rapid growth and a poor response to the medical and surgical treatment options. The role of magnetic resonance imaging (MRI) is fundamental to assess tumor aggressiveness before surgical exploration. Distinction between cavernous sinus invasion and cavernous sinus compression is often challenging and cannot be solved always by using the Knosp criteria. Ideally, T2W images demonstrating the ruptured internal dural wall of cavernous sinus is the ultimate proof of cavernous sinus invasion. Subtle tumor volume increase in a short time can be shown when sequential MR images are rigorously replicable. A microcystic pattern observed on T2W images frequently reflects a potentially aggressive tumor as observed in silent corticotroph pituitary adenomas.

Pituitary Adenomas and Invasiveness from Anatomo-Surgical, Radiological, and Histological Perspectives: A Systematic Literature Review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intra-operative and histological findings.

[Endonasal endoscopic surgery in pituitary adenomas: Surgical results in a series of 86 consecutive patients]

INTRODUCTION

The endoscopic endonasal approach has become the gold standard for the surgical treatment of pituitary adenomas.

OBJECTIVES

The aim of this study is to present the results obtained in our hospital in purely endoscopic surgery of pituitary adenomas.

METHODS

From February 2011 to August 2016, we conducted a prospective study on a series of 86 patients with pituitary adenoma, all of whom underwent surgery with a purely endoscopic endonasal approach. The 'four hands-two nostrils' technique was performed in all cases by a surgical team composed of an ENT surgeon and a neurosurgeon. Mean follow-up was 32 months. All patients were evaluated according to clinical, radiological and endocrinological criteria.

RESULTS

In our series, 53% were women and 47% men. The age ranged from 14 to 84 years of age, with a mean of 54 years of age. The most common initial symptom was visual deficit (42%), followed by hormonal hyperfunction (21%), with acromegaly being the most common clinical syndrome. The most common tumours were non-functioning tumours (73%), while GH-secreting tumours (65%) were the most common functioning adenoma. Regarding tumour size, 76% were macroadenomas, 11% microadenomas and 13% giant adenomas. Approximately 63% of the adenomas exhibited suprasellar extension and 37% involved invasion of the cavernous sinus (Knosp grade ≥3). Total excision was achieved in 77% of the cases. After the intervention, visual improvement was achieved in 91% and remission of endocrine hyperfunction in up to a 73% of cases. The most common complication was anterior pituitary insufficiency of at least one axis (9%). There were no cases of postoperative cerebrospinal fluid fistula.

CONCLUSIONS

In terms of surgical quality, our results are similar to those of published series, and demonstrate the efficacy and safety of the endoscopic endonasal approach as the surgical treatment of choice for pituitary adenomas. However, further studies with a higher sample size are necessary to obtain clinically significant results.

Cavernous Sinus Involvement by Pituitary Adenomas: Clinical Implications and Outcomes of Endoscopic Endonasal Resection

Background  Parasellar invasion of pituitary adenomas (PAs) into the cavernous sinus (CS) is common. The management of the CS component of PA remains controversial. Objective  The objective of this study was to analyze CS involvement in PA treated with endoscopic endonasal approaches, including incidence, surgical risks, surgical strategies, long-term outcomes, and our treatment algorithm. Methods  We reviewed a series of 176 surgically treated PA with particular attention to CS involvement and whether the CS tumor was approached medial or lateral to the internal carotid artery. Results  The median duration of follow-up was 36 months. Macroadenomas and nonfunctional adenomas represented 77 and 60% of cases, respectively. CS invasion was documented in 23% of cases. CS involvement was associated with a significantly diminished odds of gross total resection (47 vs. 86%, odds ratio [OR]: 5.2) and increased the need for subsequent intervention (4 vs. 40%, OR: 14.4). Hormonal remission was achieved in 15% of hormonally active tumors. Rates of surgical complication were similar regardless of CS involvement. Conclusion  Our tailored strategy beginning with a medial approach and adding lateral exposure as needed resulted in good outcomes with low morbidity in nonfunctional adenomas. Functional adenomas involving the CS were associated with low rates of hormonal remission necessitating higher rates of additional treatment.

Quantitative analysis of anatomical relationship between cavernous segment internal carotid artery and pituitary macroadenoma

Cavernous segment internal carotid artery (CSICA) injury during endoscopic transsphenoidal surgery for pituitary tumor is rare but fatal. The aim of this study is to investigate anatomical relationship between pituitary macroadenoma and corresponding CSICA using quantitative means with a sense to improve safety of surgery.In this retrospective study, a total of 98 patients with nonfunctioning pituitary macroadenomas undergoing endoscopic transsphenoidal surgeries were enrolled from 2005 to 2014. Intercarotid distances between bilateral CSICAs were measured in the 4 coronal levels, namely optic strut, convexity of carotid prominence, median sella turcica, and dorsum sellae. Parasellar extension was graded and recorded by Knosp-Steiner classification.Our findings indicated a linear relationship between size of pituitary macroadenoma and intercarotid distance over CSICA. The correlation was absent in pituitary macroadenoma with Knosp-Steiner grade 4 parasellar extension.Bigger pituitary macroadenoma makes more lateral deviation of CSICA. While facing larger tumor, sufficient bony graft is indicated for increasing surgical field, working area and operative safety.

Three-Tesla imaging of the pituitary and parasellar region: T1-weighted 3-dimensional fast spin echo cube outperforms conventional 2-dimensional magnetic resonance imaging

OBJECTIVE

We explored how a novel T1-weighted 3-dimensional (3D) fast spin echo (FSE) sequence (Cube; GE, Waukesha, Wis) might outperform conventional 2-dimensional (2D) FSE techniques for contrast-enhanced imaging of the pituitary and parasellar region.

METHODS

Ninety-one patients were imaged with 3D Cube and conventional 2D FSE on a 3.0-T magnetic resonance scanner. Two neuroradiologists independently assessed images for anatomical delineation (infundibulum, optic apparatus, and cavernous sinus), degree of artifact, and confidence in lesion definition or exclusion using a 5-point scale. In addition, the readers were asked to rank overall preference.

RESULTS

Readers A and B found 3D Cube to be better or equal to 2D FSE in 84% and 86% of the cases. Three-dimensional Cube provided significantly better images than 2D FSE with respect to delineation of the infundibulum (P < 0.0001), cavernous sinus (P < 0.0001), optic apparatus (P = 0.002 for reader A and P = 0.265 for reader B), and fewer artifacts at the sellar floor (P < 0.0001). Three-dimensional Cube provided greater lesion conspicuity or confidence in lesion exclusion (P < 0.0001).

CONCLUSIONS

Three-dimensional Cube provides superior quality with thinner slices as well as diminished artifact and can replace conventional 2D FSE sequences for routine evaluations of the pituitary and parasellar region.