Dokumentenart: | Artikel | ||||
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Open Access Art: | DEAL (Springer) - Nicht UR | ||||
Titel eines Journals oder einer Zeitschrift: | Annals of Nuclear Medicine | ||||
Verlag: | SPRINGER | ||||
Ort der Veröffentlichung: | NEW YORK | ||||
Band: | 34 | ||||
Nummer des Zeitschriftenheftes oder des Kapitels: | 4 | ||||
Seitenbereich: | S. 244-253 | ||||
Datum: | 2020 | ||||
Institutionen: | Biologie und Vorklinische Medizin > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Elmar Lang | ||||
Identifikationsnummer: |
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Stichwörter / Keywords: | RECEPTOR RADIONUCLIDE THERAPY; ENETS CONSENSUS GUIDELINES; CHROMOGRANIN-A; RESPONSE EVALUATION; PROGNOSTIC-FACTORS; TYR(3) OCTREOTATE; PEPTIDE; LU-177; NEOPLASMS; MIDGUT; Monte Carlo simulations; Dosimetry; Lu-177-DOTATOC; Neuroendocrine tumors | ||||
Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften, Biologie | ||||
Status: | Veröffentlicht | ||||
Begutachtet: | Ja, diese Version wurde begutachtet | ||||
An der Universität Regensburg entstanden: | Ja | ||||
Dokumenten-ID: | 50283 |
Zusammenfassung
Background Patients with advanced neuroendocrine tumors (NETs) of the midgut are suitable candidates for Lu-177-DOTATOC therapy. Integrated SPECT/CT systems have the potential to help improve the accuracy of patient-specific tumor dosimetry. Dose estimations to target organs are generally performed using the Medical Internal Radiation Dose scheme. We present a novel Monte Carlo-based voxel-wise ...
Zusammenfassung
Background Patients with advanced neuroendocrine tumors (NETs) of the midgut are suitable candidates for Lu-177-DOTATOC therapy. Integrated SPECT/CT systems have the potential to help improve the accuracy of patient-specific tumor dosimetry. Dose estimations to target organs are generally performed using the Medical Internal Radiation Dose scheme. We present a novel Monte Carlo-based voxel-wise dosimetry approach to determine organ- and tumor-specific total tumor doses (TTD). Methods A cohort of 14 patients with histologically confirmed metastasized NETs of the midgut (11 men, 3 women, 62.3 +/- 11.0 years of age) underwent a total of 39 cycles of Lu-177-DOTATOC therapy (mean 2.8 cycles, SD +/- 1 cycle). After the first cycle of therapy, regions of interest were defined manually on the SPECT/CT images for the kidneys, the spleen, and all 198 tracer-positive tumor lesions in the field of view. Four SPECT images, taken at 4 h, 24 h, 48 h and 72 h after injection of the radiopharmaceutical, were used to determine their effective half-lives in the structures of interest. The absorbed doses were calculated by a three-dimensional dosimetry method based on Monte Carlo simulations. TTD was calculated as the sum of all products of single tumor doses with single tumor volumes divided by the sum of all tumor volumes. Results The average dose values per cycle were 3.41 +/- 1.28 Gy (1.91-6.22 Gy) for the kidneys, 4.40 +/- 2.90 Gy (1.14-11.22 Gy) for the spleen, and 9.70 +/- 8.96 Gy (1.47-39.49 Gy) for all Lu-177-DOTATOC-positive tumor lesions. Low- and intermediate-grade tumors (G 1-2) absorbed a higher TTD compared to high-grade tumors (G 3) (signed-rank test, p = < 0.05). The pre-therapeutic chromogranin A (CgA) value and the TTD correlated significantly (Pearson correlation: = 0.67, p = 0.01). Higher TTD resulted in a significant decrease of CgA after therapy. Conclusion These results suggest that Monte Carlo-based voxel-wise dosimetry is a very promising tool for predicting the absorbed TTD based on histological and clinical parameters.
Metadaten zuletzt geändert: 11 Okt 2021 13:01