FDG-PET/CT imaging for staging and target volume delineation in conformal radiotherapy of anal carcinoma

Background: FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy. Methods: Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data. Results: PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case. Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 7 10-4) and CT-CTV (p = 2.9 7 10-4). PET/CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 7 10-5) and CT-CTV (p = 6 7 10-5). Conclusions: FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging

Ce doped SiO₂ optical fibers for remote radiation sensing and measurement

Scintillating materials, able to efficiently operate the conversion of energy absorbed in the form of ionizing radiation into light in the visible UV interval, are presently used in a wide class of applications as medical imaging, industrial inspection, security controls and high energy physics detector. In the last few years we studied and developed a new radiation sensor based on silica-glass fiber-optic technology. In its simplest configuration such device is composed by a short portion (about 10 mm) of scintillating fiber coupled to a photomultiplier by a suitably long passive silica fiber.At the early stage of its market introduction it is the smallest radiation sensor, also with respect to MOSFET and diode technology and it appears to be the ideal choice for in vivo measurements in medical field or remote sensing

Patients undergoing multiphase CT scans and receiving a cumulative effective dose of 65\u2009100\ua0mSv in a single episode of care

OBJECTIVES: To estimate the number of patients who receive a cumulative effective dose (CED) of 65100mSv from computed tomography (CT) in a single day or episode of care.METHODS: We examined 28,870 patients who underwent 49,834 CT examinations in a tertiary care centre in Italy in 2.5years. Radiation exposures were retrieved from the hospital's automatic exposure monitoring system. Two cohorts were identified as those who received a CED of 65100mSv in a single day and within a month starting from the first examination. Organ doses were estimated for the first cohort.RESULTS: Among the 1765 (6.1%) patients who received CED 65100mSv in the observation period, 427 received a CED of 65100mSv within a month (and 70 patients in a single day). This group represented 1.5% of all patients who underwent CT exams and 24% of those who received CED 65100mSv in the observation period. The clinical indication for referral included cancer in 132 patients (31%) and non-oncological indications in 295 patients (69%). In 68/70 patients with CED>100mSv in a single day, at least one organ/tissue received a dose of 65100mGy.CONCLUSIONS: The finding of a sizeable percentage of patients undergoing CT exams and receiving CED 65100mSv in a single episode of care points toward the need of imaging appropriateness criteria, to revise the routine protocols, to replace older machines, and to provide to the radiologist the patient's prior radiation history to facilitate an appropriate decision-making process.KEY POINTS: Patients can receive effective doses greater than 100mSv in a single CT or in multiple CT examinations performed in a single episode of care in 1.5% of patients in a 2.5-year period. In this study, the clinical indication for CT referral was non-oncological in 69% of patients. The patient's prior radiation history should be provided to the referring physicians and the radiological medical practitioner to facilitate an appropriate decision-making process

Cumulative radiation exposure from radiological imaging in patients with Hodgkin and diffuse large b-cell lymphoma not submitted to radiotherapy

Objective: To assess the cumulated exposure to radiation due to imaging in Hodgkin (HL) and diffuse large B-cell (DLBCL) lymphoma patients who were not submitted to radiotherapy. Methods: The study population included 51 and 83 adult patients with HL and DLBCL, with a follow-up duration >1 year. The cumulated exposure was expressed using patient-specific data as cumulated effective dose (CED). Results: Fifty-one HL patients (median age 47 years) were followed for a median of 3.5 years. The median total CED per subject was 104 mSv. CT and PET/CT examinations accounted for 75 and 25% of the total CED, respectively. 26 patients (49%) had a total CED ≥ 100 mSv and the maximum CED was 302 mSv. Eighty-three DLBCL patients (median age 66 years) were followed for a median of 3.7 years. The median total CED per subject over the study period was 134 mSv. CT and PET/CT for 86% and 13% of the total CED, respectively. 56 patients (67%) had a total CED ≥100 mSv. The maximum CED was 557 mSv. Conclusion: Our study demonstrated the large number of imaging procedures performed for patients with lymphoma. Overall, 61% of the patients accrued a CED ≥ 100 mSv. Imaging policies were only in a partial agreement with current international guidelines. Advances in knowledge: The cumulated exposure radiation exposure may be of concern in HL patients and the contribution of CT procedures to the total CED is significant. The standardisation of clinical guidelines for managing patients with lymphoma is warranted

Direct ink writing of silica-carbon-calcite composite scaffolds from a silicone resin and fillers

Calcite-based composite scaffolds have been successfully 3D-printed by direct ink writing, starting from a paste comprising a silicone polymer and calcite (CaCO3) powders. The firing in nitrogen, at 600 \ub0C, after preliminary cross-linking step at 350 \ub0C, determined the transformation of the polymer matrix into a silica-carbon nano-composite, embedding unreacted calcite particles. Compared to previously developed silica-calcite scaffolds, obtained after firing in air, the new composites exhibited a significant strength improvement (up to 3c10 MPa, for a total open porosity of 56%). The new formulation did not compromise the in vitro bioactivity and the biocompatibility of the scaffolds, as shown by dissolution studies in SBF and preliminary cell culture tests, with human fibroblasts. Due to the simplicity of the processing and the outstanding mechanical performances, the developed scaffolds are promising candidates for bone tissue engineering applications

Evaluation of operator eye exposure and eye protective devices in interventional radiology: Results on clinical staff and phantom

Purpose: To assess occupational eye lens dose based on clinical monitoring of interventional radiologists and to assess personal protective eyewear (PPE) efficacy through measurements with anthropomorphic phantom. Methods: Two positions of the operator with respect to X-ray beam were simulated with phantom. Dose reduction factor (DRF) of four PPE was assessed, as well as correlation between eye lens and whole-body doses. Brain dose was also assessed. Five radiologists were monitored for one-year clinical procedures. All subjects were equipped with whole-body dosimeter placed over lead apron at the chest level and eye lens dosimeter placed over the left side of the PPE. Kerma-Area Product (KAP) of procedures performed during the monitoring period was recorded. The correlation of eye lens dose with whole-body dose and KAP was assessed. Results: DRF was 4.3/2.4 for wraparound glasses, 4.8/1.9 for fitover glasses, 9.1/6.8 for full-face visor in radial/femoral geometries. DRF of half-face visor depended on how it is worn (range 1.0-4.9). Statistically significant correlation between dose value over the PPE and chest dose was observed, while there was no correlation between eye lens dose and chest dose. The results on clinical staff showed statistically significant correlation between dose values over the PPE and KAP. Conclusions: All PPE showed significant DRF in all configurations, provided they were worn correctly. Single DRF value is not applicable to all clinical situations. KAP is a valuable tool for determining appropriate radiation protection measures

Prognostic Impact of Sarcopenia’s Occurrence during Radiotherapy in Oropharyngeal Cancer Patients

The current study aims to profile sarcopenic condition (both at baseline and developed during treatment) in oropharyngeal carcinoma (OPC) patients treated with curative radiotherapy (RT) +/− chemotherapy and to evaluate its impact on oncological outcomes and toxicity. A total of 116 patients were included in this retrospective single-center study. Sarcopenia assessment at baseline and at 50 Gy re-evaluation CT was obtained from two different methodologies: (i) the L3-skeletal muscle index (SMI) derived from the contouring of the cross-sectional area (CSA) of the masticatory muscles (CSA-MM); and (ii) the paravertebral and sternocleidomastoid muscles at the level of the third cervical vertebra (CSA-C3). Based on L3-SMI from CSA-MM, developing sarcopenic condition during RT (on-RT sarcopenia) was associated with worse progression-free survival (PFS) (p = 0.03) on multivariable analysis and a trend of correlation with overall survival (OS) was also evident (p = 0.05). According to L3-SMI derived from CSA-C3, on-RT sarcopenia was associated with worse PFS (p = 0.0096) and OS (p = 0.013) on univariate analysis; these associations were not confirmed on multivariable analysis. A significant association was reported between becoming on-RT sarcopenia and low baseline haemoglobin (p = 0.03) and the activation of nutritional counselling (p = 0.02). No significant associations were found between sarcopenia and worse RT toxicity. Our data suggest that the implementation of prompt nutritional support to prevent the onset of sarcopenia during RT could improve oncological outcomes in OPC setting

Prognostic Impact of Sarcopenia’s Occurrence during Radiotherapy in Oropharyngeal Cancer Patients

The current study aims to profile sarcopenic condition (both at baseline and developed during treatment) in oropharyngeal carcinoma (OPC) patients treated with curative radiotherapy (RT) +/− chemotherapy and to evaluate its impact on oncological outcomes and toxicity. A total of 116 patients were included in this retrospective single-center study. Sarcopenia assessment at baseline and at 50 Gy re-evaluation CT was obtained from two different methodologies: (i) the L3-skeletal muscle index (SMI) derived from the contouring of the cross-sectional area (CSA) of the masticatory muscles (CSA-MM); and (ii) the paravertebral and sternocleidomastoid muscles at the level of the third cervical vertebra (CSA-C3). Based on L3-SMI from CSA-MM, developing sarcopenic condition during RT (on-RT sarcopenia) was associated with worse progression-free survival (PFS) (p = 0.03) on multivariable analysis and a trend of correlation with overall survival (OS) was also evident (p = 0.05). According to L3-SMI derived from CSA-C3, on-RT sarcopenia was associated with worse PFS (p = 0.0096) and OS (p = 0.013) on univariate analysis; these associations were not confirmed on multivariable analysis. A significant association was reported between becoming on-RT sarcopenia and low baseline haemoglobin (p = 0.03) and the activation of nutritional counselling (p = 0.02). No significant associations were found between sarcopenia and worse RT toxicity. Our data suggest that the implementation of prompt nutritional support to prevent the onset of sarcopenia during RT could improve oncological outcomes in OPC setting