Purpose Our center adopted high-dose-rate brachytherapy with surface applicators (plesiotherapy) in 2008, creating custom molds to treat irregular areas. This study describes the efficacy and safety outcomes after extensive follow-up in the patients. Methods/patients We planned the treatment using two computed tomography (CT) scans: the first to delineate the lesion and the second after placing the thermoplastic mold. Fusing the two CT images enables planning of the target volume and pinpointing, where the catheters are in the mold. Results Seventy patients received plesiotherapy, either exclusively or following excision in patients with risk factors for recurrence. Those receiving plesiotherapy alone showed a complete response rate of 95.8%, and recurrences occurred in 5.7% at a mean follow-up of 96.2 months. Chronic toxicity appeared in 26.6% of patients, but severity was limited to grade 1 or 2. Conclusions High-dose-rate brachytherapy with customized molds yields a high rate of complete response, with long-term recurrence rates in line with similar studies and an acceptable toxicity rate.
PURPOSE Our primary endpoint is to determine the effect of L-glutamine Resource (Nestlé Healthcare Nutrition) in the prevention of induced enteritis after pelvic radiotherapy (RT). METHODS We observed the incidence of diarrhoea during and after pelvic radiation therapy in patients receiving L-glutamine Resource (Nestlé Healthcare Nutrition) supplementation. To assess results, patients were stratified according to prior treatment (prior surgery and/or concomitant chemotherapy, or no prior or concomitant treatment). RESULTS Incidence of diarrhoea observed is similar to published series in which glutamine is not administered. Grade 1 intestinal toxicity was observed in 4 patients (15.4%), grade 2 in 10 patients (38.4%) and grade 3 in 5 patients (19.2%). Mean dose of RT at the start of enteritis was 23.55 Gy (12-40). No grade 4 toxicity occurred and in 7 patients (27%) no toxicity was reported. No differences in toxicity incidence were observed between RT dose levels. CONCLUSIONS Administration of glutamine to patients during pelvic RT does not appear to prevent the incidence of enteritis (diarrhoea). No differences were observed between patients who underwent concomitant chemotherapy (where you would expect an increase in toxicity) and those who did not.
Purpose Virtual monoenergetic images (VMI) obtained from Dual‐Energy Computed Tomography (DECT) with iodinated contrast are used in radiotherapy of the Head and Neck to improve the delineation of target volumes and organs at‐risk (OAR). The energies used to vary from 40 to 70 keV, but noise at low keV and the use of Single Energy CT (SECT) at low kVp settings may shrink this interval. There is no guide about how to find out the optimal range where VMI has a significant improvement related to SECT images. Our study proposes a procedure to determine this optimal range, based on common image quality parameters, and establishes this range in a Siemens Somatom Confidence and a Head and Neck protocol. Methods We compared the quality of the VMI series at 40–60 keV versus single X‐ray tube voltage computed tomography (SECT) at 80 and 120 kVp. Our reference was 120 kVp. DECT images were sequentially acquired using the Siemens Somatom Confidence RT Pro CT according to the head and neck protocol in our department. VMI series were constructed using the Syngo Via software Monoenergetic+ algorithm. Quality parameters were: image uniformity, high‐ and low‐contrast resolution, noise, and sensitivity to the iodinated contrast. We used the Catphan 604 phantom for quality control, except when assessing iodine sensitivity. To evaluate high contrast resolution, we calculated the modulation transfer function (MTF) using the point spread function estimation of a point bead and the slanted edge methods. For the low‐contrast resolution, we used a statistical method for assessing differences between contrast structures and local noise. To measure the absolute value of noise and compare its texture, we used the standard deviation and the noise power spectrum. We measured iodine sensitivity by dissolving the Optiray Ultraject iodinated contrast in water in concentrations of 0 to 4500 mg/l and then compared the contrast to noise ratio (CNR) and analyzed the linear correlation between concentration and HU. Results The entire series met the minimum quality requirements. However, the one at 40 keV presented uniformity at the limits of acceptability. The high‐ and low‐contrast resolutions were similar between series. The noise of the VMI series decreased with increasing energy, while sensitivity to the contrast displayed the opposite behavior. All series showed linearity of HUs from very low iodine concentrations. Images at 60 keV presented lower iodine sensitivity than SECT at 80 kVp, while those at 55 keV were similar to them. Conclusions Our method of image comparison based on standard quality parameters in phantom gave clear results about the optimal range and can be used as a guide to characterize any other DECT imaging protocols. The optimal range for using VMI images in iodinated contrasts in the Siemens system was 45–55 keV. Lower energies lacked noise and uniformity, while higher ones could be substituted by SECT images at low kilovoltage (80 kVp).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.