Comparison of sequential planar 177Lu-DOTA-TATE dosimetry scans with 68Ga-DOTA-TATE PET/CT images in patients with metastasized neuroendocrine tumours undergoing peptide receptor radionuclide therapy

• Published in: European journal of nuclear medicine and molecular imaging 2012-03, Vol.39 (3), p.501-511
• Main Authors: Sainz-Esteban, Aurora, Prasad, Vikas, Schuchardt, Christiane, Zachert, Carolin, Carril, José Manuel, Baum, Richard P.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Cardiology; Female; Humans; Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Multimodal Imaging - methods; Neoplasm Metastasis; Neuroendocrine Tumors - diagnostic imaging; Neuroendocrine Tumors - pathology; Neuroendocrine Tumors - radiotherapy; Nuclear Medicine; Octreotide - analogs & derivatives; Oncology; Organometallic Compounds; Original Article; Orthopedics; Positron-Emission Tomography; Radiology; Radiometry; Receptors, Peptide - therapeutic use; Retrospective Studies; Time Factors; Tomography, X-Ray Computed; Young Adult
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-011-2003-x

Purpose The aim of the study was to compare sequential 177 Lu-DOTA-TATE planar scans ( 177 Lu-DOTA-TATE) in patients with metastasized neuroendocrine tumours (NET) acquired during peptide receptor radionuclide therapy (PRRT) for dosimetry purposes with the pre-therapeutic 68 Ga-DOTA-TATE positron emission tomography (PET)/CT ( 68 Ga-DOTA-TATE) maximum intensity projection (MIP) images obtained in the same patients concerning the sensitivity of the different methods. Methods A total of 44 patients (59 ± 11 years old) with biopsy-proven NET underwent 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE imaging within 7.9 ± 7.5 days between the two examinations. 177 Lu-DOTA-TATE planar images were acquired at 0.5, 2, 24, 48 and 72 h post-injection; lesions were given a score from 0 to 4 depending on the uptake of the radiopharmaceutical (0 being lowest and 4 highest). The number of tumour lesions which were identified on 177 Lu-DOTA-TATE scans (in relation to the acquisition time after injection of the therapeutic dose as well as with regard to the body region) was compared to those detected on 68 Ga-DOTA-TATE studies obtained before PRRT. Results A total of 318 lesions were detected; 280 (88%) lesions were concordant. Among the discordant lesions, 29 were 68 Ga-DOTA-TATE positive and 177 Lu-DOTA-TATE negative, whereas 9 were 68 Ga-DOTA-TATE negative and 177 Lu-DOTA-TATE positive. The sensitivity, positive predictive value and accuracy for 177 Lu-DOTA-TATE as compared to 68 Ga-DOTA-TATE were 91, 97 and 88%, respectively. Significantly more lesions were seen on the delayed (72 h) 177 Lu-DOTA-TATE images (91%) as compared to the immediate (30 min) images (68%). The highest concordance was observed for bone metastases (97%) and the lowest for head/neck lesions (75%). Concordant lesions ( n  = 77; mean size 3.8 cm) were significantly larger than discordant lesions ( n  = 38; mean size 1.6 cm) ( p