Improved target volume definition for fractionated stereotactic radiotherapy in patients with intracranial meningiomas by correlation of CT, MRI, and [{sup 68}Ga]-DOTATOC-PET

Journal Article · Mon May 01 04:00:00 EDT 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2005.1· OSTI ID:20793478

Milker-Zabel, Stefanie ^[1]; Zabel-du Bois, Angelika ^[1]; Henze, Marcus ^[2]; Huber, Peter ^[3]; Schulz-Ertner, Daniela ^[1]; Hoess, Angelika ^[4]; Haberkorn, Uwe ^[2]; Debus, Juergen ^[1]

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1. Department of Radiation Oncology, Radiation Therapy, University of Heidelberg, Heidelberg (Germany)
2. Department of Nuclear Medicine, University of Heidelberg, Heidelberg (Germany)
3. Department of Radiotherapy, German Cancer Research Center, Heidelberg (Germany)
4. Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany)

Purpose: To evaluate the influence of {sup 68}-Ga-labeled DOTA ( )-D-Phe ({sup 1})-Tyr ({sup 3})-Octreotide positron emission tomography ([{sup 68}Ga]-DOTATOC-PET) for target definition for fractionated stereotactic radiotherapy (FSRT) as a complementary modality to computed tomography (CT) and magnetic resonance imaging (MRI). Because meningiomas show a high expression of somatostatin receptor subtype 2, somatostatin analogs such as DOTATOC offer the possibility of receptor-targeted imaging. Patients and Methods: Twenty-six patients received stereotactic CT, MRI, and [{sup 68}Ga]-DOTATOC-PET as part of their treatment planning. Histology was: World Health Organization (WHO) Grade 1 61.5%, WHO Grade 2 7.7%, WHO Grade 3 3.9%, and undetermined 26.9%. Six patients received radiotherapy as primary treatment, 2 after subtotal resection; 17 patients were treated for recurrent disease. Dynamic PET scans were acquired before radiotherapy over 60 min after intravenous injection of 156 {+-} 29 MBq [{sup 68}Ga]-DOTATOC. These PET images were imported in the planning software for FSRT. Planning target volume (PTV)-I outlined on CT and contrast-enhanced MRI was compared with PTV-II outlined on PET. PTV-III was defined with CT, MRI, and PET and was actually used for radiotherapy treatment. Results: PTV-III was smaller than PTV-I in 9 patients, the same size in 7 patients, and larger in 10 patients. Median PTV-I was 49.6 cc, median PTV-III was 57.2 cc. In all patients [{sup 68}Ga]-DOTATOC-PET delivered additional information concerning tumor extension. PTV-III was significantly modified based on DOTATOC-PET data in 19 patients. In 1 patient no tumor was exactly identified on CT/MRI but was visible on PET. Conclusion: These data demonstrate that [{sup 68}Ga]-DOTATOC-PET improves target definition for FSRT in patients with intracranial meningiomas. Radiation targeting with fused DOTATOC-PET, CT, and MRI resulted in significant alterations in target definition in 73%.

• OSTI ID: 20793478
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 1 Vol. 65; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GALLIUM 68
HISTOLOGY
IMAGES
INTRAVENOUS INJECTION
NEOPLASMS
NMR IMAGING
PATIENTS
PLANNING
POSITRON COMPUTED TOMOGRAPHY
RADIOTHERAPY
RECEPTORS
SOMATOSTATIN