Summary In loco-regionally advanced head and neck squamous cell cancer (HNSCC), concurrent 3-weekly cisplatin improves overall survival (OS) compared to radiotherapy alone, but is often associated ...with renal toxicity. The use of radiotherapy with accelerated fractionation schedules has been reported to improve survival but its optimal combination with chemotherapy is unclear. Retrospective analysis of treatment outcome and nephrotoxicity of radiotherapy given with an intensity-modulated approach (IMRT) concurrent with either 3-weekly or weekly cisplatin in 94 patients with stage III/IV HNSCC. Patients treated with weekly cisplatin were significantly older ( p = 0.0014) and received a significantly lower total cisplatin dose ( p = 0.0002). With a median follow-up of 2.8 years, at univariate analysis, 3-weekly cisplatin shows a longer OS ( p = 0.041) but progression-free survival (PFS) is similar for both schedules ( p = 0.47). Cisplatin doses >240 mg/m2 were associated with better OS but not PFS. Chronic renal failure rate was significantly higher with 3-weekly cisplatin ( p = 0.04). Multivariate analysis (Cox regression controlling for age) confirmed the significant and independent impact of alcohol and smoking habits on both PFS (HR, 2.2) and OS (HR, 2.3), while the treatment schedule affected only OS (HR, 2.2). Weekly cisplatin is less nephrotoxic. Both schedules can be combined to curative IMRT. PFS was not significantly different even if patients treated with the weekly schedule were significantly older and received reduced cisplatin doses. The study suggests that the different cisplatin dose doesn’t affect the PFS results if concomitant to IMRT. Controlled prospective studies are needed.
•3 MOSkins were assembled over a common rectal probe to perform in vivo dosimetry.•Mean discrepancy between measured and calculated doses was 2.2±6.9%.•89.2% of the measurements resulted in dose ...discrepancies within ±10%.•Discrepancy between planned and measured doses increases with planning time.
Three MOSkins dosimeters were assembled over a rectal probe and used to perform in vivo dosimetry during HDR brachytherapy treatments of vaginal cancer. The purpose of this study was to verify the applicability of the developed tool to evaluate discrepancies between planned and measured doses to the rectal wall.
MOSkin dosimeters from the Centre for Medical Radiation Physics are particularly suitable for brachytherapy procedures for their ability to be easily incorporated into treatment instrumentation. In this study, 26 treatment sessions of HDR vaginal brachytherapy were monitored using three MOSkin mounted on a rectal probe. A total of 78 measurements were collected and compared to doses determined by the treatment planning system.
Mean dose discrepancy was determined as 2.2±6.9%, with 44.6% of the measurements within ±5%, 89.2% within ±10% and 10.8% higher than ±10%. When dose discrepancies were grouped according to the time elapsed between imaging and treatment (i.e., group 1: ≤90min; group 2: >90min), mean discrepancies resulted in 4.7±3.6% and 7.1±5.0% for groups 1 and 2, respectively. Furthermore, the position of the dosimeter on the rectal catheter was found to affect uncertainty, where highest uncertainties were observed for the dosimeter furthest inside the rectum.
This study has verified MOSkin applicability to in-patient dose monitoring in gynecological brachytherapy procedures, demonstrating the dosimetric rectal probe setup as an accurate and convenient IVD instrument for rectal wall dose verification. Furthermore, the study demonstrates that the delivered dose discrepancy may be affected by the duration of treatment planning.
Purpose
To evaluate acute and late skin/subcutaneous toxicities and radiation-induced lung fibrosis (RILF) in patients treated with adjuvant radiotherapy (RT) for synchronous bilateral breast cancers ...(SBBC), after conservative surgery.
Methods/patients
Twenty-five patients were treated with volumetric-modulated arc therapy (VMAT/RapidArc
®
) on both breasts, and checked clinically for detecting RT toxicities during and after treatment. A high-resolution computed tomography (HRCT) was performed, for detecting RILF during follow-up.
Results
We registered acute Grade-1 skin toxicity in 18 patients (72%), while six patients (24%) experienced Grade-2 toxicity. No breath symptoms were reported during and after RT. Late Grade-1 subcutaneous toxicity and late Grade-2 skin toxicity were registered in four patients (16%) and one patient (4%), respectively, at a mean follow-up of 36 months. Grade-1 RILF was detected in six patients (30%). The median volume of fibrosis area was 6.5 cc (range 1.3–21.5 cc). The partial volumes receiving a specified dose (V20, V30, V40, and V50) in patients who developed lung fibrosis were significantly bigger than who did not (
p
< 0.01). We showed that the mean volume of the tumour boost of patients who developed fibrosis (77.7 cc) was not significantly different from the other patients (90.8 cc) (
p
= 0.5).
Conclusion
The clinical impact of this technique is favourable, and this is the first clinical study showing RILF by HRCT in a setting of SBBC. Further study with larger accrual is mandatory.
This study assessed the role of 18F-FDG PET-CT (PET/CT) to detect the cartilage and paraglottic infiltration in advanced glottic cancer comparing the results with those of conventional imaging (CI) ...(contrast-enhanced computed tomography and/or magnetic resonance). In addition, we assessed the prognostic value of quantitative parameters, measured on baseline PET/CT, in terms of event-free survival (EFS) and overall survival (OS). We retrospectively analyzed 27 patients with glottic squamous cell carcinoma stage III and IVA, treated in our institute between 2010 and 2016, comparing PET/CT, performed for staging and radiotherapy planning, and CI findings. Cohen’s K was used to compare concordance between PET/CT and CI. Imaging findings were correlated with endoscopic evaluation and histological reports (gold standard (GS)). All lesions shown by CI were also detected by PET/CT imaging, and in 5 cases, a better definition of local infiltration was achieved with PET/CT than CI (5 CT). Sensitivity, specificity, and accuracy of PET/CT and CT were 95%, 86%, and 93% and 70%, 86%, and 74% for, respectively. MRI showed sensitivity and specificity of 100%. One false-negative (FN) cases and 1 false-positive (FP) case were observed with PET/CT with no difference compared to MRI (10 cases). Six FN cases and 1 FP case were observed with CT. Cohen’s K was 0.60 (PET vs. CI) and 0.80 (PET vs. GS). Patients were followed-up for at least 24 months to calculate EFS and OS. 13 local recurrence and 7 deaths were recorded. Among quantitative PET parameters, baseline MTV was the most powerful predictor of outcome. Our data suggest a reliable sensitivity and accuracy of PET/CT in the evaluation of local extension, proving a useful method for initial local staging in addition to the well-established role in lymph-node and distant sites assessment. Furthermore, pretreatment MTV provides better prognostic information than other PET/CT parameters.
This case study investigates low-energy alternatives to distillation for the recovery of N-methyl-2-pyrrolidone (NMP) from solvent waste in the manufacture of resin precursors. Evaluation includes ...environmental and economic life cycle assessment of solvent recovery and reuse using batch distillation, solvent extraction, and solvent extraction at a sister plant. Solvent extraction at the sister plant involved shipment of hazardous waste to a facility with existing solvent recovery equipment and lower purity standards for NMP. The amount of processing required to recover useful NMP is reduced, increasing reductions in life cycle emissions and damages to the environment. Extraction at the sister plant recovered 98% of the NMP at a purity of 97.1 wt% from aqueous waste containing 17 wt% NMP. Extraction at the sister plant reduced total and CO
life cycle emissions by 61% and 59%, respectively. Compared to the distillation recovery alternative, extraction at the sister plant results in reductions of 32% and 33% for total and CO
life cycle emissions, respectively. Annual operating costs were reduced by 80%, with no capital investment, due to utilization of existing equipment. This resulted in a 10-year net present value (NPV) of $4.20 million, whereas distillation resulted in a 10-year NPV of $3.12 million.
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