Rushi Chen1, Yan Bai2, Mathias Nittka3, Gregor Koerzdoerfer3, Xianchang Zhang4, and Meiyun Wang2
1Henan provincial people's hospital& Zhengzhou University People’s Hospital, Zhengzhou, China, 2Henan provincial people's hospital, Zhengzhou, China, 3MR Pre-development, Siemens Healthcare, Erlangen, Germany, 4MR Collaboration, Siemens Healthcare Ltd, Beijing, China
Synopsis
Currently, there is no effective pharmacological
treatment for non-functioning pituitary adenoma, including gonadotroph adenoma
(GPA). Recent findings showed that an alternative pharmacological treatment
targeted at somatostatin receptor 3 may be promising, which required accurate
diagnosis of GPA before surgery. This study aimed to evaluate the utility of
magnetic resonance fingerprinting (MRF) in the pre-surgical differentiation of GPA
from non-functioning, non-gonadotropin adenoma (NGPA). The results showed that
GPAs have significantly higher T1 and T2 values in the solid tumor than NGPA,
suggesting that MRF may have potential for diagnosing GPA and benefit its
treatment plan.
Introduction
Currently, there is no effective pharmacological
treatment for non-functioning pituitary adenoma (NFPA), including gonadotroph
pituitary adenoma (GPA), which is the most prevalent subtype of NPFA. The
therapeutic alternatives include surgery and post-operative radiation. Recent
studies found a high expression of somatostatin receptor 3 (SSTR3) in GPA and
suggested that pasireotide with SSTR3 as the target is a promising alterative pharmacological
treatment [1],
thus avoiding unnecessary surgical damage. This pharmacological treatment
requires the accurate differential diagnosis of GPA before surgery. However,
the diagnosis of GPA relies on histological characterization. Conventional imaging
cannot differentiate GPA from non-gonadotropin pituitary adenoma (NGPA) before surgery,
which may prohibit the application of this treatment. Magnetic resonance
fingerprinting (MRF) is a novel technique that enables the direct derivation of
tissue-characteristic quantities such as proton density and relaxation
constants T1 and T2. Therefore, this study aimed to evaluate the utility of MRF
in the preoperative differentiation of GPA and NGPA.Methods
Twenty-three subjects (10 males; mean age: 55.1
years) with pathologically confirmed, non-functioning adenomas were enrolled. All the subjects were scanned before surgery on a 3T MAGNETOM Skyra
(Siemens Healthcare, Erlangen,
Germany) scanner using
a 20-channel head/neck coil. The MR protocol included
the following sequences: conventional MRI (2D T1-weighted,
2D T2-weighted) and a prototype spiral fast imaging with
steady-state precession (FISP) MRF (FOV = 256 x 256 mm2; matrix = 256 x 256; slice thickness
= 5 mm; flip angle
variable = 0° - 74°; random TR between 12.1 ms and 15.0 ms; 3000 measurements; and 41 s/slice; 18 slices). The quantitative T1 and T2 maps were generated by matching the measured MRF signal time course to the dictionary. According to
immunohistochemistry results, the patients were divided into a GPA group (n = 10)
and NGPA (n = 13) group.
Two radiologists blinded to the clinical information analyzed the data
independently. Regions of interests (ROIs) were manually drawn on the tumor. The Mann-Whitney U test was used to compare the T1 and T2 values
in the solid tumor between
the GPA group and NGPA group. Significance was set at P < 0.05. Receiver operating characteristic (ROC) curves were devised to evaluate the diagnostic
performance.Results
MR images and T1
and T2 values for one patient with GPA and another patient with NGPA are shown
in Figure 1 and Figure 2, respectively. The conventional MR images showed
little difference, whereas the quantitative T1 and T2 maps could provide more
information for a differential diagnosis.
As shown in Figure
3, the GPAs had significantly higher T1 values (mean ± standard deviation, 1603[BM(DMM1] ± 163 vs. 1445 ± 202 ms,
P = 0.013) and T2 value (mean ± standard deviation, 86 ± 21 vs. 67 ± 19 ms, P =
0.041) than NGPA. The ROC curves for each modality are shown in Figure 4. The area
under the ROC curves of T1 and T2 were 0.745 and 0.792, respectively.
[BM(DMM1]Avoid pseudo-accuracy that is not justified.Discussion
As the most prevalent subtype of NPFA, GPA often
presents as invasive macro-adenoma not amenable to complete surgical resection.
Radiotherapy is the only post-operative option for patients with large invasive
or recurrent lesions. Recent findings suggest that SSTR3-targeted
pharmacological treatment is a promising alternative to standard primary
surgery for GPA [1, 2].
Therefore, a method that could accurately differentiate GPA from NGPA before
surgery is essential and will benefit the treatment plan for GPA. Our results
showed that GPA had significantly higher T1 and T2 values in the solid tumor
than NGPA. Moreover, both the T1 and T2 values showed good diagnostic
performance, with T2 demonstrating slightly better diagnostic efficacy, indicating
that MRF as a completely non-invasive and quantitative imaging method may have
the potential for diagnosing gonadotroph adenoma before surgery, which will benefit the treatment plan
and thus avoid unnecessary surgery damage with this lesion.Conclusion
MRF provides a non-invasive imaging method
for the preoperative differentiation of non-functioning gonadotroph adenoma and
non-functioning non-gonadotropin adenoma. The quantitative information yield by
MRF may have a potential for guiding the treatment plan of non-functioning
gonadotroph adenoma in the future.Acknowledgements
This research was supported by the National Key R&D Program of China (2017YFE0103600), National Natural Science Foundation of China (81720108021, 81601466), and Zhongyuan Thousand Talents Plan Project-- Basic Research Leader Talent (ZYQR201810117).References
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Beschorner R, Honegger J, Schlegel J, Shively T, Pulz E, Schulz S et al: SSTR3 is a putative target for the medical treatment of gonadotroph
adenomas of the pituitary. Endocr
Relat Cancer 2015, 22(1):111-119.
2. Taboada GF, Luque RM, Bastos W, Guimaraes
RF, Marcondes JB, Chimelli LM, Fontes R, Mata PJ, Filho PN, Carvalho DP et al: Quantitative analysis of somatostatin receptor subtype (SSTR1-5) gene
expression levels in somatotropinomas and non-functioning pituitary adenomas.
Eur J Endocrinol 2007, 156(1):65-74.