Pilot scale validation campaign of gel dosimetry for pre-treatment quality assurance in stereotactic radiotherapy

PURPOSE

Complex stereotactic radiotherapy treatment plans require prior verification. A gel dosimetry system was developed and tested to serve as a high-resolution 3D dosimeter for Quality Assurance (QA) purposes.

MATERIALS AND METHODS

A modified version of a polyacrylamide polymer gel dosimeter based on chemical response inhibition was employed. Different sample geometries (cuvettes and phantoms) were manufactured for calibration and QA acquisitions. Irradiations were performed with a Varian Trilogy linac, and analyses of irradiated gel dosimeters were performed via MRI with a 1.5 T Philips Achieva at 1 mm3 or 2 mm3 isotropic spatial resolution. To assess reliability of polymer gel data, 54 stereotactic clinical treatment plans were delivered both on dosimetric gel phantoms and on the Delta4 dosimeter. Results from the two devices were evaluated through a global gamma index over a range of acceptance criteria and compared with each other.

RESULTS

A quantitative and tunable control of dosimetric gel response sensitivity was achieved through chemical inhibition. An optimized MRI analysis protocol allowed to acquire high resolution phantom dose data in timeframes of ≈ 1 h. Conversion of gel dosimeter data into absorbed dose was achieved through internal calibration. Polymer gel dosimeters (2 mm3 resolution) and Delta4 presented an agreement within 4.8 % and 2.7 % at the 3 %/1 mm and 2 %/2 mm gamma criteria, respectively.

CONCLUSIONS

Gel dosimeters appear as promising tools for high resolution 3D QA. Added complexity of the gel dosimetry protocol may be justifiable in case of small target volumes and steep dose gradients.

Study of inelastic nuclear interactions of 400 GeV/c protons in bent silicon crystals for beam steering purposes

Inelastic nuclear interaction probability of 400 GeV/c protons interacting with bent silicon crystals was investigated, in particular for both types of crystals installed at the CERN Large Hadron Collider for beam collimation purposes. In comparison to amorphous scattering interaction, in planar channeling this probability is ∼ 36 % for the quasi-mosaic type (planes (111)), and ∼ 27 % for the strip type (planes (110)). Moreover, the absolute inelastic nuclear interaction probability in the axial channeling orientation, along the ⟨ 110 ⟩ axis, was estimated for the first time, finding a value of 0.6 % for a crystal 2 mm long along the beam direction, with a bending angle of 55 μ rad. This value is more than two times lower with respect to the planar channeling orientation of the same crystal, and increases with the vertical angular misalignment. Finally, the correlation between the inelastic nuclear interaction probability in the planar channeling and the silicon crystal curvature is reported.

Ultrasound elastography is a reproducible and feasible tool for the evaluation of the patellar tendon in healthy subjects

OBJECTIVE

To evaluate the feasibility and reproducibility of ultrasound elastography (UE) in the assessment of healthy patellar tendon and to describe its UE pattern.

METHODS

Twenty-two patellar tendons of 11 out of 16 healthy subjects who met the inclusion criteria were evaluated three times by ultrasound (US) and UE at their proximal, middle and distal portions, by two separate sonographers with different experiences in UE.

RESULTS

In all tendon portions the color map analysis showed a predominance of green (highly elastic), with good values of intra-observer (Operator 1: P-values = 0.790, 0.864, 0.865; Operator 2: P = 0.642, 0.882, 0.613 for proximal, middle and distal portions, respectively) and inter-observer (P = 0.657) agreement. For both operators the intra-observer analysis of the elasticity ratio (ER) between the tendon and the subcutis showed high agreement values (P < 0.001 for both operators). The inter-observer analysis showed also high agreement values (P < 0.001 at proximal, P = 0.001 at middle, P = 0.005 at distal portions). The overall analysis of the ER of the tendon portions showed values of (mean ± SD): 1.47 ± 0.64, 4.38 ± 1.36, 3.32 ± 1.20 for proximal, middle and distal portions, respectively. The mean time to perform the UE evaluation for the inexperienced operator was 5 min at the beginning of the study but decreased to 2 min after a few examinations were done. The mean time for the expert was 2 min for the entire study.

CONCLUSIONS

UE is a feasible and reproducible tool for the evaluation of the healthy patellar tendon and further data are needed to define its role in the assessment of tendon pathology.

The Italian version of the Mouth Handicap in Systemic Sclerosis scale (MHISS) is valid, reliable and useful in assessing oral health-related quality of life (OHRQoL) in systemic sclerosis (SSc) patients

In systemic sclerosis (SSc), mouth and face involvement leads to problems in oral health-related quality of life (OHRQoL). Mouth Handicap in Systemic Sclerosis scale (MHISS) is a 12-item questionnaire specifically quantifying mouth disability in SSc, organized in 3 subscales. Our aim was to validate Italian version of MHISS, by assessing its test-retest reliability and internal and external consistency in Italian SSc patients. Forty SSc patients (7 dSSc, 33 lSSc; age and disease duration: 57.27 ± 11.41, 9.4 ± 4.4 years; 22 with sicca syndrome) were evaluated with MHISS. MHISS was translated following a forward-backward translation procedure, with independent translations and counter-translation. Test-retest reliability was evaluated, comparing the results of two administrations, with intraclass correlation coefficient (ICC). Internal consistency was assessed by Cronbach's α and external consistency by comparison with mouth opening. MHISS has a good test-retest reliability (ICC: 0.93) and internal consistency (Cronbach's α:0.99). A good external consistency was confirmed by correlation with mouth opening (rho: -0,3869, p: 0.0137). Total MHISS score was 17.65 ± 5.20, with scores of subscale 1 (reduced mouth opening) of 6.60 ± 2.85 and scores of subscales 2 (sicca syndrome) and 3 (aesthetic concerns) of 7.82 ± 2.59 and 3.22 ± 1.14. Total and subscale 2 scores are higher in dSSc than in lSSc. This result may be due to the higher presence of sicca syndrome in dSSc than in lSSc (p = 0.0109). Our results support validity and reliability in Italian SSc patients of MHISS, specifically measuring SSc OHRQoL.

The efficacy of the Rességuier method in the treatment of fibromyalgia syndrome: a randomized controlled trial

OBJECTIVES

In fibromyalgia syndrome (FMS) defined rehabilitation guidelines are yet to be validated. Our aim is to evaluate the efficacy of the Rességuier method (RM) in FMS.

METHODS

Forty-one patients were randomly assigned to Interventional (22 pts) and Observational (19 pts) Group (IG and OG). The study lasted 8 months. Patients were assessed at baseline (T0) after a 2-month rehabilitation (T1) and at a 6-month follow-up (T2) (only IG) with SF-36 Physical (PSI) and Mental Synthetic Index (MSI), Regional Pain Scale (RPS), Fibromyalgia Impact Questionnaire (FIQ), Number Rating Scales 0-10 to measure pain, movement quality, sleep, relax ability, analgesics number/per week. OG patients maintained their lifestyle for the duration of the study. RM aims to obtain patient awareness and control of bodily perceptions, thus reaching a modulation of responses to pain. Therapist controls patient attention and perception by verbal and manual contacts and leads them to perform bodily and respiratory active and conscious movements.

RESULTS

In IG, at T1 all items were improved: PSI and MSI (p<0.001 and =0.001), FIQ (p<0.0001), RPS (p<0.001), pain (p<0.0001), movement quality (p=0.001), relax ability (p<0.0001), sleep (p<0.001); analgesics number/per week was reduced (p<0.001). All results obtained at T1, except FIQ, were maintained at T2. In OG at T1 versus T0, no difference in any of the assessed parameters was observed.

CONCLUSION

In FMS patients, the rehabilitation with RM improves HRQoL, FMS-related disability and perceived pain, thus reducing the assumption of analgesics.

Examination of periodontal pathogens in stenotic valve specimens and in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis

Periodontitis may be a risk factor for atherosclerosis and coronary heart disease. The influence of periodontal pathogens in cardiovascular diseases needs further investigation. Therefore, the aims of this clinical study are: to test the presence of periodontal bacteria DNA in aortic valves and to assess the concomitant presence of the same periodontal bacteria DNA in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis. Nineteen consecutive patients (12 males and 7 females, age: 49-85 years) were enrolled in this study after having been subjected to a complete periodontal evaluation to confirm the diagnosis of chronic periodontitis. All patients were scheduled for aortic valve replacement surgery. After clinical and microbial periodontal examination, the aortic valve tissue specimens were obtained by excision during valve replacement surgery and the patients were subjected to the whole blood sampling before the surgery. The polymerase chain reaction technology was used to detect the putative periodontal pathogens Tannerella forshytia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens and Treponema denticola. Neither the 19 aortic valve specimens nor the blood samples were positive for the genoma of the selected periodontal pathogens. The selected periodontal pathogens did not colonize the aortic valve of patients affected by stenosis and bacterial genoma was not present in whole blood samples. A high blood pressure at the aortic valve may prevent the adhesion and proliferation of bacterial colonies.

Efficacy of a tailored rehabilitation program for systemic sclerosis

INTRODUCTION

Rehabilitation may contribute to the management of Systemic Sclerosis (SSc) dealing with disabilities due to skin and joint involvement.

AIM

to evaluate the efficacy of a district specific and global rehabilitation program tailored for SSc patients.

MATERIALS AND METHODS

20 SSc patients were enrolled and randomly assigned to 2 groups. Interventional group (10 pts) was treated that included hand and face specific rehabilitation and at least a global rehabilitation technique such as hydrokinesytherapy or land-based program, also comprising respiratory exercises. Hand lymphatic drainage was added when necessary. Observational group (10 patients) was only provided with educational advices and medical information about SSc. Patients were evaluated at baseline (T0) and after the 9 weeks treatment period (T1). Interventional group was also assessed after a 9 weeks follow-up (T2). Patients were evaluated by SF-36, HAQ and a purpose-built-questionnaire for global health condition and with Hamis test, Duruöz scale, range of motion, water volumetric test, mouth opening and a purpose-built-questionnaire for hand and face involvement.

RESULTS

At the end of the treatment, patients of interventional group improved in all the parameters evaluated. At follow-up, mouth mobility and functionality such as global health status was partially lost, only hand mobility and functionality parameters were maintained. No changes were observed in controls.

CONCLUSION

The association and of district-specific and global rehabilitative techniques conceived and tailored for SSc patients improves disability, HRQoL, hand and face disability and functionality, with its effects partially maintained at the follow-up.

Vitamin E gel reduces time of healing of digital ulcers in systemic sclerosis

BACKGROUND

In systemic sclerosis (SSc), digital ulcers (DU) are painful, difficult to heal and frequently infected, thus greatly affecting quality of life and increasing SSc-related disability. Vitamin E has been previously used in cutaneous lesions for its antioxidant and anti-inflammatory effects.

OBJECTIVES

To study the healing effect of D-alpha-tocopheryl acetate (acetic ester of alpha-tocopherol) (VE) gel on DU of SSc patients.

METHODS

27 SSc patients with a total of 86 DU were enrolled in an open pilot study. The patients were randomly assigned to two groups: 15 patients were treated until DU healing with the local standard ulcer care protocol with the application of vitamin E gel (experimental group), while 12 patients were treated with standard ulcer care protocol only (control group). In both groups, DU were treated twice a week and pain was scored by a NRS (numeric rating scale). In both groups the cost of medications was analysed.

RESULTS

VE induced a faster healing of DU in respect to controls (13.22+/-2.72 weeks, versus 20.94+/-3.65; p<0.0001) with a lower number of medications (26.18+/-5.63 vs. 41.88+/-7.31; p<0.0001). Resolution of pain was faster in experimental (17.82+/-4,59 medications) than in controls (26.26+/-19.16 medications) (p=0.0022). In the experimental group, the cost of medications was significantly lower (6,919.15 euros/patient) than in the control group (11,056.32 euros/patient).

CONCLUSION

The application of VE reduces time of healing and has a faster resolution of pain, with a significant reduction of costs. Topical VE may improve the management of DU in SSc.