Clinical impact of (99m)Tc-MAA SPECT/CT-based dosimetry in the radioembolization of liver malignancies with (90)Y-loaded microspheres.
Radioembolization with (90)Y-loaded microspheres is increasingly used in the treatment of primary and secondary liver cancer. Technetium-99 m macroaggregated albumin (MAA) scintigraphy is used as a surrogate of microsphere distribution to assess lung or digestive shunting prior to therapy, based on tumoral targeting and dosimetry. To date, this has been the sole pre-therapeutic tool available for such evaluation. Several dosimetric approaches have been described using both glass and resin microspheres in hepatocellular carcinoma (HCC) and liver metastasis. Given that each product offers different specific activities and numbers of spheres injected, their radiobiological properties are believed to lightly differ. This paper summarizes and discusses the available studies focused on MAA-based dosimetry, particularly concentrating on potential confounding factors like clinical context, tumor size, cirrhosis, previous or concomitant therapy, and product used. In terms of the impact of tumoral dose in HCC, the results were concordant and a response relationship and tumoral threshold dose was clearly identified, especially in studies using glass microspheres. Tumoral dose has also been found to influence survival. The concept of treatment intensification has recently been introduced, yet despite several studies publishing interesting findings on the tumor dose-metastasis relationship, no consensus has been reached, and further clarification is thus required. Nor has the maximal tolerated dose to the liver been well documented, requiring more accurate evaluation. Lung dose was well described, despite recently identified factors influencing its evaluation, requiring further assessment. Conclusion: MAA SPECT/CT dosimetry is accurate in HCC and can now be used in order to achieve a fully customized approach, including treatment intensification. Yet further studies are warranted for the metastasis setting and evaluating the maximal tolerated liver dose.
Department of Nuclear Medicine, Cancer Institute Eugène Marquis, CS 44229, F-35042, Rennes, France. e.garin@rennes.unicancer.fr.|University of Rennes 1, F-35043, Rennes, France. e.garin@rennes.unicancer.fr.|INSERM, U-991, Liver Metabolisms and Cancer, F-35033, Rennes, France. e.garin@rennes.unicancer.fr.
Etienne
E
Garin
Department of Medical Imaging, Cancer Institute Eugène Marquis, CS 44229, F-35042, Rennes, France.
Yan
Y
Rolland
University of Rennes 1, F-35043, Rennes, France.
Sophie
S
Laffont
University of Rennes 1, F-35043, Rennes, France.|INSERM, U-991, Liver Metabolisms and Cancer, F-35033, Rennes, France.|Department of Medical Oncology, Cancer Institute Eugène Marquis, CS 44229, F-35042, Rennes, France.
Julien
J
Edeline
D000792:Angiography; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000628:therapy*; D004621:Embolization, Therapeutic; D005898:Glass / Q000737:chemistry; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008168:Lung / Q000000981:diagnostic imaging; D020714:Maximum Tolerated Dose; D008863:Microspheres; D009010:Monte Carlo Method; D009362:Neoplasm Metastasis; D011874:Radiometry; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D013668:Technetium Tc 99m Aggregated Albumin / Q000737:chemistry; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes
Predictive dosimetry; Prognosis; Selective internal radiation therapy