Our objective was to evaluate the biodistribution, kinetics, and radiation dosimetry of CuCl in humans and to assess the ability of CuCl PET/CT to detect prostate cancer (PCa) recurrence in patients with biochemical relapse. We prospectively evaluated 50 PCa patients with biochemical relapse after surgery or external-beam radiation therapy. All patients underwentCuCl PET/CT, F-choline PET/CT, and multiparametric MRI within 15 d of each other. Experienced readers interpreted the images, and the detection rate (DR) of each imaging modality was calculated. Histopathology, when available; clinical or laboratory response; and multidisciplinary follow-up were used to confirm the site of disease. In parallel, biodistribution, kinetics of the lesions, and radiation dosimetry ofCuCl were evaluated. From a dosimetric point of view, an administered dose of 200 MBq forCuCl translated into a 5.7-mSv effective dose. Unlike F-choline,CuCl was not excreted or accumulated in the urinary tract, thus allowing thorough pelvic exploration. The maximum CuCl uptake at the sites of PCa relapse was observed 1 h after tracer injection. In our cohort, CuCl PET/CT proved positive in 41 of 50 patients, with an overall DR of 82%. The DRs of F-choline PET/CT and multiparametric MRI were 56% and 74%, respectively. The difference between the DRs ofCuCl PET/CT and F-choline PET/CT was statistically significant ( < 0.001). Interestingly, on considering prostate-specific antigen (PSA) value, CuCl PET/CT had a higher DR than F-choline PET/CT in patients with a PSA of less than 1 ng/mL. The biodistribution of CuCl is more suitable than that of F-choline for exploring the pelvis and prostatic bed. TheCuCl effective dose is like those of other established PET tracers. In patients with biochemical relapse and a low PSA level, CuCl PET/CT shows a significantly higher DR than F-choline PET/CT.
In the authors' hospital, stereotactic radiotherapy treatments are performed with a Varian Clinac 600C equipped with a BrainLAB m3 micro-multileaf-collimator generally using the dynamic conformal arc technique. Patient immobilization during the treatment is achieved with a fixation mask supplied by BrainLAB, made with two reinforced thermoplastic sheets fitting the patient's head. With this work the authors propose a method to evaluate treatment geometric accuracy and, consequently, to determine the amount of the margin to keep in the CTV-PTV expansion during the treatment planning. The reproducibility of the isocenter position was tested by simulating a complete treatment on the anthropomorphic phantom Alderson Rando, inserting in between two phantom slices a high sensitivity Gafchromic EBT film, properly prepared and calibrated, and repeating several treatment sessions, each time removing the fixing mask and replacing the film inside the phantom. The comparison between the dose distributions measured on films and computed by TPS, after a precise image registration procedure performed by a commercial piece of software (FILMQA, 3cognition LLC (Division of ISP), Wayne, NJ), allowed the authors to measure the repositioning errors, obtaining about 0.5 mm in case of central spherical PTV and about 1.5 mm in case of peripheral irregular PTV. Moreover, an evaluation of the errors in the registration procedure was performed, giving negligible values with respect to the quantities to be measured. The above intrinsic two-dimensional estimate of treatment accuracy has to be increased for the error in the third dimension, but the 2 mm margin the authors generally use for the CTV-PTV expansion seems adequate anyway. Using the same EBT films, a dosimetric verification of the treatment planning system was done. Measured dose values are larger or smaller than the nominal ones depending on geometric irradiation conditions, but, in the authors' experimental conditions, always within 4%.
Fluconazole is recommended in the prophylaxis of oropharyngeal candidiasis (OPC) in patients undergoing radiotherapy for head-neck tumours; however, the actual effectiveness of fluconazole in this setting remains unclear. Adult patients with cervico-cephalic carcinoma submitted to radical or adjuvant radiotherapy were randomized to 100 mg fluconazole (n = 138) or matched placebo (n = 132) oral suspension once daily from the sixth session of radiotherapy up to the end of treatment. The final analysis of the investigation showed a higher rate of the OPC outbreak-free survival in the fluconazole compared with placebo (P = 0.008 in the log-rank test). The mean time (95% CI) to OPC outbreak was 56 (53-59) days in the fluconazole group and 47 (43-51) days with placebo. The mean duration of radiotherapy was 43.5 and 39.9 days, respectively in the two groups (P = 0.027). Adverse effects were reported in 70.3% of patients in the fluconazole group and in 67.4% with placebo. The results showed prophylaxis with fluconazole given in irradiated patients with head-neck tumours significantly reduces the rate and the time to development of OPC compared with placebo.
Colorectal cancer patients’ responses to neoadjuvant therapy undergo broad inter-individual variations. The aim of this systematic review is to identify a molecular signature that is predictive of colon cancer downstaging and/or downgrading after neoadjuvant therapy. Among the hundreds analysed in the available studies, only 19 messenger-RNAs (mRNAs) and six micro-RNAs (miRNAs) were differentially expressed in responders versus non-responders in two or more independent studies. Therefore, a mRNA/miRNA signature can be designed accordingly, with limitations caused by the retrospective nature of these studies, the heterogeneity in study designs and the downgrading/downstaging assessment criteria. This signature can be proposed to tailor neoadjuvant therapy regimens on an individual basis.
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