Moderately hypofractionated proton beam therapy for localized prostate cancer: 5-year outcomes of a phase II trial.

The usefulness of moderately hypofractionated radiotherapy for localized prostate cancer has been extensively reported, but there are limited studies on proton beam therapy (PBT) using similar hypofractionation schedules. The aim of this prospective phase II study is to confirm the safety of a shortened PBT course using 70 Gy relative biological effectiveness (RBE) in 28 fractions. From May 2013 to June 2015, 102 men with localized prostate cancer were enrolled. Androgen deprivation therapy was administered according to risk classification. Toxicity was assessed using Common Terminology Criteria for Adverse Events version 4.0. Of the 100 patients ultimately evaluated, 15 were classified as low risk, 43 as intermediate risk, and 42 as high risk. The median follow-up time of the surviving patients was 96 months (range: 60-119 months). The 5-year cumulative incidences of grade 2 gastrointestinal/genitourinary adverse events were 1% (95% CI: 0.1-6.9) and 4% (95% CI: 1.5-10.3), respectively; no grade ≥ 3 gastrointestinal/genitourinary adverse events were observed. The current study revealed a low incidence of late adverse events in prostate cancer patients treated with moderately hypofractionated PBT of 70 Gy (RBE) in 28 fractions, indicating the safety of this schedule.

Phase I/IIa PET imaging study with 89zirconium labeled anti-PSMA minibody for urological malignancies.

OBJECTIVE: We conducted the present phase I/IIa positron emission tomography (PET) imaging study with 89Zr conjugated with desferroxamine-IAB2M (89Zr-Df-IAB2M), an anti-prostate-specific membrane-antigen minibody, to assess its safety and feasibility in patients with urological cancer. METHODS: 89Zr-Df-IAB2M was synthetized by IBA Molecular (Somerset, NJ, USA) and transported by air to Tsukuba Molecular Imaging Center (Tsukuba, Ibaraki, Japan).17 patients received 74 MBq (2 mCi) of 89Zr-Df-IAB2M at total mass doses of 10 mg. Whole-body and plasma clearance, normal-organ and lesion uptake, and radiation absorbed dose were estimated. We also preliminarily tested the performance of 89Zr-immuno-PET imaging for 13 patients with prostate cancer and 4 patients with other urological cancer. RESULTS: The administration of 89Zr-Df-IAB2M was well-tolerated, and no infusion-related reactions were observed in any patient. No adverse events were noted in the laboratory parameters, vital signs, or other parameters. The plasma clearance was biphasic, with an initial rapid phase (t 1/2 fast: 10.1 ± 3.4 h) followed by a slow phase (t 1/2 slow: 49.0 ± 22.7 h). The half-life of radioactivity in the whole body (WB t1/2) was 237 ± 9 h. The highest absorbed radiation dose was 1.67 mGy/MBq, observed in the liver and kidney. The effective dose was 0.68 ± 0.08 mSv/MBq. The radiation dose rate at 0.5 m distance from the patient was 8.67 µSv/h on day 1, and decreased to 2.26 µSv/h at 5 days after injection. Both bone and lymph node metastases were detected with 89Zr-Df-IAB2M by 24 or 48 h imaging. CONCLUSIONS: Administration of 89Zr-Df-IAB2M was well-tolerated and safe in terms of adverse events and radiation exposure and protection. 89Zr-Df-IAB2M is feasible for usage by long-distance transportation. Further studies are warranted for analysis of its use for tumor lesion detection (UMIN000015356).

Potential use of prostate specific membrane antigen (PSMA) for detecting the tumor neovasculature of brain tumors by PET imaging with 89Zr-Df-IAB2M anti-PSMA minibody.

Tumor angiogenesis has attracted increasing attention because of its potential as a valuable marker in the differential diagnosis of brain tumors as well as a novel therapeutic target. Prostate-specific membrane antigen (PSMA) is expressed by the neovasculature endothelium of some tumors, with little to no expression by the tumor cells or normal vasculature endothelium. The aim of this study was to investigate the potential of PSMA for the evaluation of the tumor neovasculature of various brain tumors and the possibility of detecting PSMA expression in brain tumors using PET imaging with 89Zr-Df-IAB2M (anti-PSMA minibody). Eighty-three tissue specimens including gliomas, metastatic brain tumors, primary central nervous system lymphomas (PCNSL), or radiation necroses were analyzed by immunohistochemical staining with PSMA antibody. 89Zr-Df-IAB2M PET scans were performed in three patients with recurrent high-grade gliomas or metastatic brain tumor. PSMA was highly expressed in the vascular endothelium of high-grade glioma and metastatic brain tumor, whereas PSMA was poorly expressed in the vascular endothelium of PCNSL and radiation necrosis. PSMA expression in high-grade gliomas and a metastatic brain tumor was clearly visualized by PET imaging with 89Zr-Df-IAB2M. Furthermore, a trend toward a positive correlation between the degree of 89Zr-Df-IAB2M uptake and PSMA expression levels in tumor specimens was observed. PET imaging of PSMA using 89Zr-Df-IAB2M may have potential value in the differential diagnosis of high-grade glioma from PCNSL or radiation necrosis as well as in the prediction of treatment efficacy and assessment of treatment response to bevacizumab therapy for high-grade glioma.

Development of RNA-FISH Assay for Detection of Oncogenic FGFR3-TACC3 Fusion Genes in FFPE Samples.

INTRODUCTION AND OBJECTIVES: Oncogenic FGFR3-TACC3 fusions and FGFR3 mutations are target candidates for small molecule inhibitors in bladder cancer (BC). Because FGFR3 and TACC3 genes are located very closely on chromosome 4p16.3, detection of the fusion by DNA-FISH (fluorescent in situ hybridization) is not a feasible option. In this study, we developed a novel RNA-FISH assay using branched DNA probe to detect FGFR3-TACC3 fusions in formaldehyde-fixed paraffin-embedded (FFPE) human BC samples. MATERIALS AND METHODS: The RNA-FISH assay was developed and validated using a mouse xenograft model with human BC cell lines. Next, we assessed the consistency of the RNA-FISH assay using 104 human BC samples. In this study, primary BC tissues were stored as frozen and FFPE tissues. FGFR3-TACC3 fusions were independently detected in FFPE sections by the RNA-FISH assay and in frozen tissues by RT-PCR. We also analyzed the presence of FGFR3 mutations by targeted sequencing of genomic DNA extracted from deparaffinized FFPE sections. RESULTS: FGFR3-TACC3 fusion transcripts were identified by RNA-FISH and RT-PCR in mouse xenograft FFPE tissues using the human BC cell lines RT112 and RT4. These cell lines have been reported to be fusion-positive. Signals for FGFR3-TACC3 fusions by RNA-FISH were positive in 2/60 (3%) of non-muscle-invasive BC (NMIBC) and 2/44 (5%) muscle-invasive BC (MIBC) patients. The results of RT-PCR of all 104 patients were identical to those of RNA-FISH. FGFR3 mutations were detected in 27/60 (45%) NMIBC and 8/44 (18%) MIBC patients. Except for one NMIBC patient, FGFR3 mutation and FGFR3-TACC3 fusion were mutually exclusive. CONCLUSIONS: We developed an RNA-FISH assay for detection of the FGFR3-TACC3 fusion in FFPE samples of human BC tissues. Screening for not only FGFR3 mutations, but also for FGFR3-TACC3 fusion transcripts has the potential to identify additional patients that can be treated with FGFR inhibitors.