Absorbed dose evaluation of a blood irradiator with alanine, TLD-100 and ionization chamber.

Irradiation of blood bags using X-ray irradiators and dosimetry services are required to ensure uniform dose levels in the range 25-50 Gy to prevent Transfusion Associated Graft versus Host Disease (TA-GvHD). An absorbed dose characterization of a Raycell MK2 X-Irradiator was performed using three different dosimetric systems. Results showed a dosimetric accuracy of the ionization chamber together with the Alanine dosimeter. TLDs measurements exhibited a small overestimation by 4% of the absorbed dose. The Dose Uniformity Ratio (DUR), between maximum and minimum dose levels in the canister, was in good agreement with the manufacturer specifications (≤1.5).

Radon surveys and effectiveness of remedial actions in spas on the Ischia island (Italy).

The possible damaging effects on human health of inhaled radon and its decay products are of interest to workers and the public. In particular, radon in thermal environments often occurs in high concentrations. Therefore, investigations and remedial actions are important to reduce activity concentration values and associated risk. This work concerns the analysis of two surveys of radon gas activity concentration carried out in 2006/2007 and 2019/2020 at twenty thermal spas on the island of Ischia (Italy). Annual measurements were carried out in workplaces located in the basement and ground floor using passive CR-39 detectors. In the spas involved in both surveys, the effectiveness of the remedial actions, implemented by the owners, was assessed obtaining an average percentage reduction of 74%. Considerations were made about the annual effective dose, and the location of the spas taking into account the geological setting of the volcanic nature of the island.

Radiation-induced acute dysphagia : Prospective observational study on 42 head and neck cancer patients.

PURPOSE: Acute toxicity in head and neck (H&N) cancer patients treated with definitive radiotherapy (RT) has a crucial role in compliance to treatments. The aim of this study was to correlate doses to swallowing-associated structures and acute dysphagia. METHODS: We prospectively analyzed 42 H&N cancer patients treated with RT. Dysphagia (grade ≥ 3) and indication for percutaneous endoscopic gastrostomy (PEG) insertion were classified as acute toxicity. Ten swallowing-related structures were considered for the dosimetric analysis. The correlation between clinical information and the dose absorbed by the contoured structures was analyzed. Multivariate logistic regression method using resampling methods (bootstrapping) was applied to select model order and parameters for normal tissue complication probability (NTCP) modelling. RESULTS: A strong multiple correlation between dosimetric parameters was found. A two-variable model was suggested as the optimal order by bootstrap method. The optimal model (Rs = 0.452, p < 0.001) includes V45 of the cervical esophagus (odds ratio [OR] = 1.016) and Dmean of the cricopharyngeal muscle (OR = 1.057). The model area under the curve was 0.82 (95% confidence interval 0.69-0.95). CONCLUSION: Our results suggested that the absorbed dose to the cricopharyngeal muscle and cervical esophagus might play a relevant role in the development of acute RT-related dysphagia.

Predictors of Asymptomatic Radiation-induced Abdominal Atherosclerosis.

AIMS: To identify predictors of asymptomatic radiation-induced abdominal atherosclerosis in patients treated with radiotherapy and evaluated by abdominal vascular ultrasonography. MATERIALS AND METHODS: Forty-two testicular classic seminoma patients (median age 34 years, range 16-56) undergoing radical inguinal orchiectomy were analysed. Twenty-six patients underwent post-surgery radiotherapy (median total dose 25 Gy, range 25-43), two of them also received chemotherapy (CHT) and 16 patients were treated with surgery alone or by surgery followed by CHT (control group). The presence of stenosis in an abdominal vessel and renal resistive index (RRI), evaluated by echo-colour Doppler (ECD), were considered as indicators of late vascular damage. Chi-square and Mann-Whitney tests were used to compare groups. For the radiotherapy group, near maximum (D2%) and mean dose (Dmean) metrics of critical structures (abdominal arteries and renal hila) were extracted from retrievable dose maps (18 of 26 radiotherapy patients). To evaluate clinical and dosimetric factors associated with vascular damage, univariate and multivariate analyses were carried out. The impact of dose to arteries, evaluated as separate subvolumes, was analysed comparing the stenotic arteries with normal ones by logistic regression. The area under the receiver operator characteristic curve (AUC) was used to evaluate the test accuracy. RESULTS: In the radiotherapy group there was a significantly different incidence of stenosis (31% versus 0%, P = 0.016) and a higher median average RRI (0.63 versus 0.60, P = 0.032) compared with the control group. The median time intervals between treatment and ECD were 64 months (range 12-120) and 48 months (range 12-168) in the radiotherapy and control groups (P = 0.399), respectively. A younger age at radiotherapy was the only clinical risk factor for stenosis (P = 0.006). Artery Dmean was significantly associated with stenosis (P = 0.008), with an odds ratio of 1.13 (95% confidence interval 1.01-1.26) and an AUC of 0.85 (95% confidence interval 0.77-0.91). Renal hilum D2% was correlated with RRI (Rs = 0.406, P = 0.02). CONCLUSIONS: Late vascular damage represents a potential effect of abdominal radiotherapy, even at a moderate dose. Younger age at irradiation, artery and renal hila dose metrics are associated with increased risk. Ultrasound-based follow-up may allow for non-invasive early detection of asymptomatic radiation-induced damage, helping to prevent severe vascular events.

[Leiomyoma of the small intestines--a rare cause of emergency abdominal surgery]. / Il leiomioma del tenue. Una rara causa di emergenza chirurgica addominale.

The authors underline that, although rarely found, leiomyomas of the gastrointestinal tract are the most frequent benign tumours of the small intestine. On occasions, from being a simple autoptic finding or diagnosed during the course of explorative laparotomy, they may be responsible for emergency abdominal surgery, hemorrhage, occlusion or perforation. The authors discuss the experience acquired in two cases-treated during the last two years, both of which were symptomatic. In one case there was a palpable abdominal mass, and in both the key symptom was the appearance of melena a few days before being admitted to hospital. The most striking problem of this rare pathology is its diagnosis owing to both the absence of a specific clinical symptoms, and the difficulties shown in radiological diagnostics of the small intestine. In the authors' experience CAT using a contrast medium is an important instrument, whereas clyster of the small intestine is of scarce value. Explorative laparotomy was essential for removing any doubts regarding diagnosis. Both patients underwent extensive intestinal resection, including the mass and relative mesenteric wedge, with TT single-layer anastomosis. The postoperative period was normal.