Potential impact of (68)Ga-DOTATOC PET/CT on stereotactic radiotherapy planning of meningiomas.

Abstract

PURPOSE:

Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planning radiotherapy. We investigated the input of (68)Ga-DOTATOC-PET/CT on the definition of the "gross tumour volume" (GTV) in meningiomas, in order to assess the potential value of this method.

METHODS:

Prior to radiotherapy, 42 patients with meningiomas (26 f, 16 m, mean age 55) underwent MRI and (68)Ga-DOTATOC-PET/CT examinations.

HISTORY:

operated n = 24, radiotherapy n = 1, operation and radiotherapy n = 8, no treatment n = 9. PET/CT and MRI data were co-registered using a BrainLAB workstation. For comparison, the GTV was defined first under consideration of CT and MRI data, then using PET data.

RESULTS:

3/42 patients were excluded from the analysis (two with negative PET results, one with an extensive tumour, not precisely delineable by MRI or PET/CT). The average GTV(CT/MRI) was 22(+/-19)cm(3); GTV(PET) was 23(+/-20)cm(3). Additional GTV, obtained as a result of PET was 9(+/-10)cm(3) and was observed in patients with osseous infiltration. In some pre-treated patients there were intratumoural areas (as identified in CT/MRI) without SR-expression (7(+/-11)cm(3)). Common GTV as obtained by both CT/MRI and PET was 15(+/-14)cm(3). The mean bi-directional difference between the GTV(CT/MRI) and GTV(PET) accounted to 16(+/-15)cm(3) (93%, p < 0.001). In a subgroup of seven patients with multiple meningiomas, PET showed a total of 19 lesions; nine of them were not recognizable by CT or MRI.

CONCLUSION:

(68)Ga-DOTATOC-PET enables delineation of SR-positive meningiomas and delivers additional information to both CT and MRI regarding the planning of stereotactic radiotherapy. The acquisition on a PET/CT scanner helps to estimate the relation of PET findings to anatomical structures and is especially useful for detection of osseous infiltration. (68)Ga-DOTATOC-PET also allows detection of additional lesions in patients with multiple meningiomas.

• Authors: Fonyuy Nyuyki, Michail Plotkin, Reinhold Graf, Roger Michel, Ingo Steffen, Timm Denecke, Lilli Geworski, Daniel Fahdt, Winfried Brenner, Reinhard Wurm
• Journal: European journal of nuclear medicine and molecular imaging (Eur J Nucl Med Mol Imaging) Vol. 37 Issue 2 Pg. 310-8 (Feb 2010) ISSN: 1619-7089 [Electronic] Germany
• PMID: 19763565 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Ga(III)-DOTATOC
• Organometallic Compounds
• Radiopharmaceuticals
• Octreotide

Topics

• Aged
• Feasibility Studies
• Humans
• Meningioma (diagnostic imaging, surgery)
• Middle Aged
• Octreotide (analogs & derivatives)
• Organometallic Compounds
• Positron-Emission Tomography (methods)
• Preoperative Care (methods)
• Prognosis
• Radiopharmaceuticals
• Radiosurgery (methods)
• Reproducibility of Results
• Sensitivity and Specificity
• Subtraction Technique
• Surgery, Computer-Assisted (methods)
• Tomography, X-Ray Computed (methods)
• Young Adult