AAPM Medical Physics Practice Guideline 14.a: Yttrium-90 microsphere radioembolization.

Radioembolization using Yttrium-90 ( Y) microspheres is widely used to treat primary and metastatic liver tumors. The present work provides minimum practice guidelines for establishing and supporting such a program. Medical physicists play a key role in patient and staff safety during these procedures.

Retrospective SPECT/CT dosimetry following transarterial radioembolization.

Transarterial radioembolization (TARE) effectively treats unresectable primary and metastatic liver tumors through intra-arterial injection of Yttrium-90 ( Y) beta particle emitting microspheres which implant around the tumor. Current dosimetry models are highly simplistic and there is a large need for an image-based dosimetry post-TARE, which would improve treatment safety and efficacy. Current post-TARE imaging is Y bremsstrahlung SPECT/CT and we study the use of these images for dosimetry.

Gamma Knife Stereotactic Radiosurgery favorably changes the clinical course of hemangioblastoma growth in von Hippel-Lindau and sporadic patients.

Purpose: This is the first single-institution study of its size to characterize the treatment impact and to address the question of whether hemangioblastoma treatment with Gamma Knife Stereotactic Radiosurgery (GKRS) in both sporadic and VHL patients changes the characteristic saltatory hemangioblastoma growth pattern.

Methods: The authors reviewed a single-institution tumor registry to identify patients who had received GKRS for hemangioblastomas between January 1st, 1999, and December 31st, 2017.

Results: 15 patients with 101 lesions met search criteria with a median age of first GKRS of 39.

Practical Guidelines for Cerenkov Luminescence Imaging with Clinically Relevant Isotopes.

Cerenkov luminescence imaging (CLI) is a relatively new imaging modality that utilizes conventional optical imaging instrumentation to detect Cerenkov radiation derived from standard and often clinically approved radiotracers. Its research versatility, low cost, and ease of use have increased its popularity within the molecular imaging community and at institutions that are interested in conducting radiotracer-based molecular imaging research, but that lack the necessary resources and infrastructure. Here, we provide a description of the materials and procedures necessary to conduct a Cerenkov luminescence imaging experiment using a variety of imaging instrumentation, radionuclides, and animal models.

Emerging Indications for Fractionated Gamma Knife Radiosurgery.

Background: Gamma Knife radiosurgery (GKRS) allows for the treatment of intracranial tumors with a high degree of dose conformality and precision. There are, however, certain situations wherein the dose conformality of GKRS is desired, but single session treatment is contraindicated. In these situations, a traditional pin-based GKRS head frame cannot be used, as it precludes fractionated treatment.

Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167.

Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved.

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for 90Y microsphere brachytherapy in the treatment of hepatic malignancies.

Yttrium-90 microsphere brachytherapy of the liver exploits the distinctive features of the liver anatomy to treat liver malignancies with beta radiation and is gaining more wide spread clinical use. This report provides a general overview of microsphere liver brachytherapy and assists the treatment team in creating local treatment practices to provide safe and efficient patient treatment. Suggestions for future improvements are incorporated with the basic rationale for the therapy and currently used procedures.

Computer modeling of controlled microsphere release and targeting in a representative hepatic artery system.

Combating liver tumors via yttrium-90 ((90)Y) radioembolization is a viable treatment option of nonresectable liver tumors. Employing clinical (90)Y microparticles (i.e.

Computer modeling of yttrium-90-microsphere transport in the hepatic arterial tree to improve clinical outcomes.

Purpose: Radioembolization (RE) via yttrium-90 ((90)Y) microspheres is an effective and safe treatment for unresectable liver malignancies. However, no data are available regarding the impact of local blood flow dynamics on (90)Y-microsphere transport and distribution in the human hepatic arterial system.

Methods And Materials: A three-dimensional (3-D) computer model was developed to analyze and simulate blood-microsphere flow dynamics in the hepatic arterial system with tumor.

A first report of radioembolization for hepatic metastases from ocular melanoma.

Background: Ocular melanoma (OM) metastasizes to the liver and is rapidly fatal despite aggressive therapy. Yttrium-90 microspheres (radioembolization) delivered via the hepatic artery is an established and effective approach for primary and metastatic hepatic tumors, although (90)Y use in OM has not been reported previously.

Methods: A retrospective review was performed for all patients with OM who received radioembolization at 5 centers.

Treatment parameters and outcome in 680 treatments of internal radiation with resin 90Y-microspheres for unresectable hepatic tumors.

Purpose: Radioembolization (RE) using (90)Y-microspheres is an effective and safe treatment for patients with unresectable liver malignancies. Radiation-induced liver disease (RILD) is rare after RE; however, greater understanding of radiation-related factors leading to serious liver toxicity is needed.

Methods And Materials: Retrospective review of radiation parameters was performed.

Radioembolization for unresectable neuroendocrine hepatic metastases using resin 90Y-microspheres: early results in 148 patients.

Purpose: The use of 90Y-microspheres to treat unresectable liver metastases originating from a variety of neuroendocrine tumors was reviewed.

Materials And Methods: This is a retrospective review from 10 institutions of patients given 90Y-microsphere therapy for neuroendocrine hepatic metastases. Physical, radiographic, biochemical, and clinical factors associated with treatment and response were examined.

Quality assurance issues for therapeutic application of radioactive microspheres.

The use of radioactive microspheres for the treatment of hepatic cancer is a procedure that raises unique quality assurance (QA) concerns. The greatest of these concerns is the coordination of the responsibilities among the medical team members from interventional radiology, radiation oncology, nuclear medicine, and medical physics. A single QA practice and procedure guidance document does not currently exist that addresses the range of issues of concern for radioactive microspheres.

Resin 90Y microsphere activity measurements for liver brachytherapy.

The measurement of the radioactivity administered to the patient is one of the major components of 90Y microsphere liver brachytherapy. The activity of 90Y microspheres in a glass delivery vial was measured in a dose calibrator. The calibration value to use for 90Y in the dose calibrator was verified using an activity calibration standard provided by the microsphere manufacturer.

Safety and efficacy of Y-90 microsphere treatment in patients with primary and metastatic liver cancer: the tumor selectivity of the treatment as a function of tumor to liver flow ratio.

Background: Treatment records and follow-up data on 40 patients with primary and metastatic liver malignancies who underwent a single whole-liver treatment with Y-90 resin microspheres (SIR-Spheres Sirtex Medical, Lake Forest, IL) were retrospectively reviewed. The objective of the study was to evaluate the anatomic and physiologic determinants of radiation dose distribution, and the dose response of tumor and liver toxicity in patients with liver malignancies who underwent hepatic arterial Y-90 resin microsphere treatment.

Methods: Liver and tumor volume calculations were performed on pre-treatment CT scans.