Assessing the readability, quality and accuracy of online health information for patients with low anterior resection syndrome following surgery for rectal cancer.

AIM: Management of low anterior resection syndrome (LARS) requires a high degree of patient engagement. This process may be facilitated by online health-related information and education. The aim of this study was to systematically review current online health information on LARS. METHOD: An online search of Google, Yahoo and Bing was performed using the search terms 'low anterior/anterior resection syndrome' and 'bowel function/movements after rectal cancer surgery'. Websites were assessed for readability (eight standardized tests), suitability (using the Suitability Assessment of Materials instrument), quality (the DISCERN instrument), accuracy and content (using a LARS-specific content checklist). Websites were categorized as academic, governmental, nonprofit or private. RESULTS: Of 117 unique websites, 25 met the inclusion criteria. The median readability level was 10.4 (9.2-11.7) and 11 (44.0%) websites were highly suitable. Using the DISCERN instrument, seven (28.0%) websites had clear aims, two (8.0%) divulged the sources used and four (16.0%) had high overall quality. Only eight (32.0%) websites defined LARS and ten (40.0%) listed all five major symptoms associated with the LARS score. There was variation in the number of websites that discussed dietary modifications (80.0%), self-help strategies (72.0%), medication (68.0%), pelvic floor rehabilitation (60.0%) and neuromodulation (8.0%). The median accuracy of websites was 93.8% (88.2-96.7%). Governmental websites scored highest for overall suitability (P = 0.0079) and quality (P < 0.001). CONCLUSIONS: Current online information on LARS is suboptimal. Websites are highly variable, important content is often lacking and material is too complex for patients.

Longitudinal neurophysiological assessment of intramuscular type-A botulin toxin in healthy humans.

The aim of this study is to assess the neurophysiological abnormalities of type A botulin toxin-infiltrated human muscle, and their evolution over time. Seried cMAP measurements, 3 and 20 Hz repetitive nerve stimulation, EMG, SFEMG over 3 months from toxin injection. Our findings consist in lack of decrement with 3 Hz repetitive nerve stimulation and facilitation with 20 Hz repetitive nerve stimulation; progressive increasing of jitter; early appearance of fibrillations; small and short motor unit action potential in the first 3 weeks, followed by increasing of MUAP amplitude and duration, with polyphasic morphology. Although claimed as highly specific and sensible, neuromuscular junction facilitation is an inconstant finding in human botulism. Therefore, lack of neuromuscular junction facilitation cannot exclude a diagnosis of botulism. Our findings are compatible with a process of acute denervation followed by distal reinnervation, favored by terminal nerve sprouting.

Indocyanine green fluorescence angiography during low anterior resection for low rectal cancer: results of a comparative cohort study.

BACKGROUND: Anastomotic leak (AL) after low anterior resection (LAR) is associated with increased morbidity, mortality, cost and cancer recurrence rates. The aim of this study was to evaluate the impact of fluorescence angiography (FA) on AL following LAR for low rectal cancer. METHODS: This is a single surgeon retrospective cohort study with a historical, consecutively sampled case matched control group. The institution's prospectively maintained institutional review board (IRB)-approved database was queried for all patients who underwent a laparoscopic LAR for rectal neoplasia with a colorectal or coloanal anastomosis < 5 cm from the anal verge between 2013 and 2016. Patients were divided into two groups: patients in whom FA was employed (study group, 2015-2016) and those patients in whom it was not (control group, 2013-2015). All patients were diverted with a loop ileostomy. The primary outcome measured was the AL rate and the secondary outcome measured was change in surgical plan following FA. RESULTS: Sixty patients were included in the study: 30 patients in the FA group and 30 patients in the control group. Patients' demographics, the use of neoadjuvant chemoradiation, tumor stage, and mean height of anastomosis were comparable between the study groups. FA led to a change in surgical plan in four patients (13.3%) none of who suffered an AL. Two patients in the control group had a clinically and radiologically confirmed AL, whereas there were no leaks in the FA group (6.7% vs. 0%, p = 0.49). CONCLUSIONS: FA changed the surgical plan in 13.3% of LAR's, potentially reducing the incidence of AL in these high-risk patients.

Social media in colorectal surgery.

The engagement of social media in healthcare continues to expand. For members of the colorectal community, social media has already made a significant impact on practice, education and patient care. The applications are unique such that they provide a platform for instant communication and information sharing with other users worldwide. The purpose of this article is to provide an overview of how social media has the potential to change clinical practice, training, research and patient care in colorectal surgery.

Periodontitis, implant loss and peri-implantitis. A meta-analysis.

OBJECTIVE: The aim of the present systematic review and meta-analysis was to assess the role of periodontal disease as a risk factor for implant loss, peri-implantitis and implant-bone loss. MATERIALS AND METHODS: Six electronic database and a manual search resulted in 7391 unique publications; after selection only 16 studies were included in systematic review. Dichotomous data were expressed as risk ratio (RR) and 95% confidence interval (CI), while continuous data were expressed as standardized mean difference (SMD). Due to the expected inter-study heterogeneity, a random effect model was used for both type of data. The pooled effect was considered significant for a P < 0.05. RESULTS: Meta-analysis revealed that an higher and significant risk for implant loss was present in patients affected by PD (RR: 1.69, 95% CI: 1.31-2.17, P < 0.0001). A higher and significant IBL was present in patients with periodontal disease, when compared with patients periodontally healthy (SMD: 0.38, 95% CI: 0.18-0.58, P = 0.0002). Patients periodontally compromised showed an increased risk of PI, when compared with patients without periodontitis (RR: 2.17, 95% CI: 1.51-3.12, P < 0.0001) No evidence of significant heterogeneity was detected for the three outcomes. CONCLUSION: Strong evidence suggests that periodontitis is a risk factor for implant loss; moderate evidence revealed that periodontitis is a risk factor for peri-implantitis and that patients with periodontitis have higher implant-bone loss.

Sleep disorders in myotonic dystrophy type 2: a controlled polysomnographic study and self-reported questionnaires.

BACKGROUND AND PURPOSE: There is a paucity of data available regarding the occurrence of sleep disorders in myotonic dystrophy type 2 (DM2). In this study the sleep-wake cycle and daytime sleepiness were investigated in DM2 patients and compared with results from healthy subjects and myotonic dystrophy type 1 (DM1) patients. METHODS: Twelve DM2 outpatients, 12 age- and sex-matched healthy controls and 18 DM1 patients were recruited. Subjective quality of sleep was assessed by means of the Pittsburgh Sleep Quality Index (PSQI). Both the Epworth Sleepiness Scale and the Daytime Sleepiness Scale were performed in order to evaluate excessive daytime sleepiness (EDS). All participants underwent polysomnographic monitoring over 48 h as well as the Multiple Sleep Latency Test. RESULTS: Sleep efficiency was < 90% in 12/12 DM2 patients, and significantly reduced when compared with controls or with DM1. Decreased sleep efficiency was associated with sleep-disordered breathing in seven out of 12 DM2 patients and/or periodic limbs movements of sleep (PLMS) in three out of eight patients. Six DM2 patients showed REM sleep without atonia, whereas none of the controls or DM1 patients showed REM sleep dysregulation. The global PSQI score was higher in DM2 patients than in controls and DM1 patients. CONCLUSIONS: Sleep quality in DM2 patients is poorer than in DM1 patients and controls. Sleep apnea is the most common sleep disorder in DM2 patients. Obstructive sleep apnea and sleep fragmentation may represent the main cause of EDS, whereas PLMS is a frequent finding in DM1.

Effectiveness of metronidazole as an adjunct to scaling and root planing in the treatment of chronic periodontitis: a systematic review and meta-analysis.

BACKGROUND: Metronidazole (MET) has been suggested as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis. However, its clinical effectiveness and effects on periodontal pathogens remain to be defined. The present meta-analysis assessed the scientific evidence concerning the effect of MET adjunctive to SRP as compared to SRP alone. METHODS: A literature search of electronic databases was performed for articles published through December 16, 2012, followed by a manual search of several dental journals. A meta-analysis was conducted according to recommendations of the Cochrane Collaboration and PRISMA. Weighted mean differences (MDs) and 95% confidence intervals (CIs) were calculated for probing depth reduction, clinical attachment level gain, bleeding on probing index and suppuration. All outcomes were evaluated as changes from baseline to the end of follow-up. Heterogeneity was assessed with the chi-squared-based Cochran Q test and I(2) statistic. The level of significance was set at p < 0.05. RESULTS: After the study selection process, six randomized clinical trials were included in the meta-analysis. The results of the meta-analysis indicated that SRP + MET provided additional benefits when compared to SRP alone in terms of probing depth reduction (MD, 0.18; 95% CI, 0.09-0.28; p < 0.05) and clinical attachment level gain (MD, 0.10; 95% CI, 0.08-0.12; p < 0.05). No evidence of heterogeneity was detected. CONCLUSION: The meta-analysis results seem to support the effectiveness of adjunctive MET with SRP compared to SRP alone. However, given the low number of included studies and limitations of meta-analysis, future studies are needed to confirm these results.

Effects of correction of Class II malocclusion on the kinesiographic pattern of young adolescents: a case- control study.

AIM: The aim of this study was to assess the dynamic activity of the mandible by means of a computerised kinesiograph in Class II patients treated with orthodontic therapy and to compare the results of this group with those of a sample of untreated Class II patients. METHODS: Twenty young adolescents who had undergone orthodontic treatment for correction of Class II malocclusion and twenty age and sex-matched adolescents exhibiting Class II malocclusion, whose parents refused the orthodontic treatment, were enrolled. Maximum vertical opening (MVO), maximum anterior-posterior movement (MAPM), maximum right deviation (MRD), maximum left deviation (MLD), MVO/ MAPM ratio, maximum velocity in opening (MVIO), maximum velocity in closure (MVIC), verticality (ID-V), anterior-posteriority (ID-AP) and laterality (ID-L) were recorded during the kinesiographic evaluations. Differences in the kinesiographic data were analysed using the Wilcoxon sum rank test; data are expressed as means and standard deviations (SD). Differences between groups in age were analysed using unpaired t-test, while differences in gender distribution were assessed using the Fisher's exact test. The level of significance was set at p < 0.05. RESULTS: No differences were detected in the distribution of sex and age between the two groups. Significant differences between the two groups were observed for MVO, MAPM, that were higher in the control group, and MLD, which was higher in the case group; no other significant differences were detected for MRD, MVO/ MAPM, MVIO, MVIC, ID-V, ID-AP, ID-L. CONCLUSION: Orthodontic treatment of young patients with Class II malocclusion may reduce the maximum vertical opening as well as the maximum anterior-posterior movement and enhance the lateral displacement; however, further studies are needed to assess the relationship between impaired mandible kinetics of orthodontic treatment in patients with Class II malocclusion and craniomandibular disorders.

Dosimetric characterization of a synthetic single crystal diamond detector in clinical radiation therapy small photon beams.

PURPOSE: To determine the potentialities of synthetic single crystal diamond Schottky diodes for accurate dose measurements in radiation therapy small photon beams. METHODS: The dosimetric properties of a diamond-based detector were assessed by comparison with a reference microionization chamber. The diamond device was operated at zero bias voltage under irradiation with high-energy radiotherapic photon beams. The stability of the detector response and its dose and dose rate dependence were measured. Different square field sizes ranging from 1 × 1 cm(2) to 10 × 10 cm(2) were used during comparative dose distribution measurements by means of percentage depth dose curves (PDDs), lateral beam profiles, and output factors. The angular and temperature dependence of the diamond detector response were also studied. RESULTS: The detector response shows a deviation from linearity of less than ±0.5% in the 0.01-7 Gy range and dose rate dependence below ±0.5% in the 1-6 Gy∕min range. PDDs and output factors are in good agreement with those measured by the reference ionization chamber within 1%. No angular dependence is observed by rotating the detector along its axis, while ∼3.5% maximum difference is measured by varying the radiation incidence angle in the polar direction. The temperature dependence was investigated as well and a ±0.2% variation of the detector response is found in the 18-40 °C range. CONCLUSIONS: The obtained results indicate the investigated synthetic diamond-based detector as a candidate for small field clinical radiation dosimetry in advanced radiation therapy techniques.

Prevalence of myopia in a population with malocclusions.

AIM: The purpose of this study was to investigate the prevalence of myopia among a paediatric population with malocclusions. MATERIALS AND METHODS: A total of 322 consecutive patients of the department of Orthodontics and Gnathology, Dental Clinic, University of L'Aquila, were enlisted for the study and 292 were selected according to the exclusion criteria. Pretreatment diagnostic data, which included radiographic cephalometric and dental cast evaluation, were recorded and presence of myopia was assessed through an ophthalmological examination. Differences in the prevalence of myopia by sex and malocclusion were analysed by using Pearson's chi-square and Fisher's exact tests. RESULTS: According to the sagittal malocclusion, patients were classified as Class I (N=162), Class II division 1 (N=75), Class II division 2 (N=38), or Class III (N=12). No gender influence was found for myopia or malocclusion. No differences were recorded when analysing the influence of sex on the prevalence of myopia in classes of malocclusion. A statistical significant higher prevalence was found for subjects showing myopia in Class II division 1 malocclusion, while no other significant differences were found for prevalence in the other classes of malocclusions. DISCUSSION: Few studies investigated a possible relationship between the ocular and stomatognathic system, and no data are available in the scientific literature. A higher prevalence of myopia was found in patients with Class II division 1: as expected no other significant association was found. CONCLUSION: The findings of the present study suggest a possible association between myopia and Class II, but further studies are needed to confirm and explain this observation.

Prevalence of astigmatism in a paediatric population with malocclusions.

AIM: The purpose of this study was to investigate the prevalence of astigmatism among a paediatric population. MATERIALS AND METHODS: A total of 322 consecutive patients of the department of Orthodontics and Gnathology, Dental Clinic, University of L'Aquila, were enlisted for the study and 176 were selected according to the exclusion criteria. Pre- treatment diagnostic data, which included radiographic cephalometric and dental cast evaluation, were recorded and presence of astigmatism was assessed through an ophthalmological examination. Differences in the prevalence of astigmatism by sex and malocclusion were analysed by using the chi-square (Pearson's chi-square test) and Fisher's exact tests. RESULTS: According to the sagittal malocclusion, patients were classified as Class I (N=122), Class II Division 1 (N=26), Class II Division 2 (N=9), or Class III (N=19); according to the transverse malocclusion patients were classified into cross-bite (N=39) and no cross-bite (N=137) groups; after ophthalmological examination astigmatism was detected in 32 patients (18.18%). Statistically significant correlations were found between astigmatism and cross-bite (p < 0.0001), while no associations were found with other malocclusions. No gender influence was found for astigmatism or malocclusion. DISCUSSION: Few study investigated a possible relationship between the ocular and stomatognathic system, and no data are available in the scientific literature. A higher prevalence of astigmatism was found in patients with cross-bite: as expected no other significant association was found. The relationship between astigmatism and cross-bite could be either related to a specific skeletal pattern, which could induce visual alterations, or to the effect of abnormal visual input on the postural system, which could induce stomatognathic alterations. CONCLUSION: The findings of the present study suggest a possible association between astigmatism and cross-bite, but future studies are needed to confirm and explain this observation.

Prevalence of hyperopia and strabismus in a paediatric population with malocclusions.

AIM: The purpose of this study was to investigate the prevalence of hyperopia and strabismus among a paediatric population with malocclusions. MATERIALS AND METHODS: From a total of 322 consecutive patients observed at the department of Orthodontics and Gnathology, Dental Clinic, University of L'Aquila, 176 were selected for the study according to the exclusion criteria. Pretreatment diagnostic data, which included radiographic, cephalometric and dental cast evaluation, were recorded and presence of hyperopia or strabismus was assessed through an ophthalmological examination. Differences in incidence rates of strabismus or hyperopia by sex and malocclusion were analysed by using the chi-square (Pearson's chi-square test) and Fisher's exact tests. RESULTS: According to the sagittal malocclusion, patients were classified as Class I (122), Class II division 1 (26), Class II Division 2 (9), or Class III (19); after ophthalmological examination, hyperopia was detected in 8.6% of patients, while strabismus was present in 3.6% of them. No gender influence was found for hyperopia, strabismus or malocclusion. DISCUSSION: Few studies investigated a possible relationship between the ocular and stomatognathic system, and no data are available in the scientific literature; the present study did not highlight differences in the prevalence of hyperopia or strabismus in the three Angle classes malocclusion. CONCLUSION: The findings of the present study did not suggest a possible association between hyperopia or strabismus and sagittal malocclusion, but future studies are needed to confirm and explain this observation.

An interdisciplinary approach to a survey on dental caries in a group of 3-year-olds in Ascoli Piceno (Italy).

AIM: The purpose of this study was to investigate the dental caries experience in a group of 3-year-old children, through an interdisciplinary protocol, both paediatric and paedodontic, in the district of Ascoli Piceno (Marche, Italy). MATERIALS AND METHODS: A sample of 82 children, 38 males and 44 females, was recruited by four paediatricians during a preliminary study phase, which consisted of the epidemiological survey explanation to the involved children's parents and informed consents collection; the survey was first planned and then performed by one calibrated examiner, (Cohen k test was 0.85) in two days on May 2008. The examinations were performed in the nurseries of the schools attended by the children. The collected data were analysed by descriptive and association statistics: the chi² test was used to investigate the association between caries and gender, assuming as statistical significance level the p < 0.05 value. RESULTS: The study revealed that caries prevalence in the observed population was 38%, while caries free group accounted for 61%; the mean dmft was 1.06, with a standard deviation of 1.64. No statistical significance was observed in the association between caries and gender (chi²=0.65, p > 0.05). discussion: Dental caries prevalence of the surveyed population, according to the WHO 2010 objectives, was judged quite high, focusing the low caries free group (61% instead of 90% or over) and the children's preschool age; nonetheless the sample situation was not considered as critical, because the WHO 2000 goals were achieved (caries free > 50%). CONCLUSION: The interdisciplinary paedodontic paediatric protocol, used in the present study, was a useful and powerful instrument for preparing the epidemiological survey and could be the basis of future preventive programs.

A pilot study on secondary anemia in "frailty" patients treated with Ferric Sodium EDTA in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine: safety of treatment explored by HRV non-linear analysis as predictive factor of cardiovascular tolerability.

OBJECTIVE: Iron deficiency anemia (IDA) in patients with heart disease is correlated with decreased exercise capacity and poor health-related quality of life, and predicts worse cardiovascular outcomes, especially for elderly patients. IDA can worsen cardiac function that can be monitored with Heart Rate Variability (HRV) analysis, providing important information about cardiac health. In a recent study we explored the effect and the tolerability of the administration of Ferric Sodium EDTA in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel Forte®) in "frailty" patients with secondary anemia and low kidney failure, by analysing the HRV frequency domain. The aim of the present study is the further confirmation of the safety of the already evaluated intervention, by analysing non-linear domain of HRV. PATIENTS AND METHODS: In this pilot study we enrolled 52 "frailty" elderly patients, with a recent diagnosis of secondary anemia due to iron deficiency, with Class II New York Heart Association (NYHA) hypertensive heart disease, low kidney failure, and atherosclerosis. The patients were divided in 2 groups: Group A (N=23 patients) received oral administration of Ferric Sodium EDTA in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel Forte®) 2 tabs/day, containing 60 mg of Fe3+, for 24 days; Group B (N=29 patients) received intravenous administration of ferrous gluconate 63 mg/day added to saline solution, while they were hospitalized (15±5 days). We evaluated laboratory values of hemoglobin (Hb) and sideremia levels. Furthermore, we measured ECG signals before and after treatment, using non-linear analysis techniques. RESULTS: Both intravenous and oral treatments evaluated in this study, were effective and safe about the cardiovascular risk in "frailty" elderly patients, as resulted from non-linear HRV analysis. Efficacy results showed that hemoglobin and sideremia levels after treatments are significantly increased. The HRV non-linear analysis showed that all parameters evaluated, except for the SD1 values in the Group A, were not affected by treatments, confirming the absence of cardiovascular risk of the therapy. CONCLUSIONS: Non-linear HRV evaluation confirmed that oral administration of Ferric Sodium EDTA, in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel forte®) did not impact the cardiovascular risk, without causing adverse events typically reported with other iron supplementation therapies, both oral and intravenous.

Management of tinnitus: oral treatment with melatonin and sulodexide.

The main problem arising from tinnitus is the disturbance it causes in day-to-day life and disturbance in sleep leading to fatigue and general discomfort. We attempted to study the effect of melatonin in conjunction with Sulodexide as a treatment method for tinnitus and evaluate its effectiveness. We studied 102 patients suffering from tinnitus with a Prospective Randomised Controlled Study conducted in a tertiary care ENT department. After randomisation, 34 patients were treated with melatonin and Sulodexide, another 34 were treated with melatonin alone, and the remaining 34 (control group) were managed without therapy in order to evaluate spontaneous variations in quality of tinnitus. Patients were assessed prospectively with Tinnitus Handicap Inventory and Acufenometry both pre-treatment and post-treatment. Among the patients we studied, we found better results with both Tinnitus Handicap Inventory and Acufenometry in the group who received melatonin and Sulodexide as against melatonin alone. Any improvement was noted in the control group. In conclusion, our opinion is that melatonin in combination with Sulodexide is a viable treatment option for patients suffering from central or sensorineural tinnitus.

Antibiotic regimen including linezolid for treating prosthetic valve endocarditis with cerebral embolism due to methicillin-susceptible Staphylococcus aureus after failure with oxacillin and teicoplanin.

A case of prosthetic valve endocarditis due to methicillin susceptible Staphylococcus aureus (MSSA) with cerebral metastatic seeding is described. The patient is a 61 year old man with diabetes mellitus, chronic renal failure and previous bacterial endocarditis. Despite appropriate MSSA therapy, the patient was eventually cured with the introduction of linezolid, without needing surgical intervention.

Management of recurrent otitis media with rapid maxillary expansion: our experience.

UNLABELLED: Management of recurrent otitis media with rapid maxillary expansion: our experience. PROBLEMS/OBJECTIVES: Recurrent otitis media is a frequent problem in the paediatric population. It is commonly associated with adenoid hypertrophy and occasionally with skeletal development syndrome characterised by maxillary anatomical alterations. When this syndrome is present in conjunction with adenoid hypertrophy, surgical management with adenoidectomy and/or myringotomy with ventilation tube positioning does not necessarily ensure a resolution of conductive hearing disorders. METHODOLOGY: We used maxillary rapid expansion in 27 children with a mean age of 7 years affected by recurrent otitis media associated with skeletal development syndrome and adenoid hypertrophy. RESULTS: Rapid maxillary expansion acting directly on the median palatine suture expands the palate and the nasal floor, improving nasal breathing. In addition, maxillary expansion stretches elevator and tensor palatine muscles, helping to restore normal Eustachian tube function, even in the presence of adenoid hypertrophy. CONCLUSION: In our opinion, rapid maxillary expansion results in an improvement in skeletal-facial abnormalities associated with skeletal development syndrome and it can be considered a valid treatment for preventing recurrent otitis media in children affected by maxillary anatomical alterations.

Loco-regional recurrence in 2064 patients with breast cancer treated with mastectomy without adjuvant radiotherapy.

INTRODUCTION: We investigated the incidence of loco-regional recurrence in a sub-group of patients who underwent mastectomy without adjuvant radiotherapy to evaluate the effect of each specific clinical or pathological parameter that could be associated with a higher local relapse rate. PATIENTS AND METHODS: Two thousand and sixty-four patients were treated from January 1971 to December 2003 at the University of Florence. RESULTS: At the time of analysis 18.3% of patients (378/2064) had isolated loco-regional failures. Univariate analysis showed an association of borderline statistical significance with pathological tumour size. Elderly age at diagnosis had a low incidence of local recurrence but the results did not reach statistical significant. The number of positive axillary lymph node did not show any influence for local recurrence. CONCLUSION: In our series we noted a higher relapse rate only related to the pathological tumour size without any correlation with number of positive axillary nodes. Radiotherapy after mastectomy still remains controversial, but in our series the number of positive axillary lymph node did not seem enough to justify adjuvant treatment.

Practical implementation of ISO 11929: 2010.

The determination of characteristic limits in the measurement of radioactive materials is an important aspect of low-level measurements and the underlying principles are well understood by scientists working on such measurements. ISO 11929:2010 provides a rigorous basis for the systematic calculation of detection limits, but may be difficult to interpret for the routine user. This paper attempts to simplify some of the more arcane aspects of this standard.

EPID-based in vivo dosimetry for stereotactic body radiotherapy of non-small cell lung tumors: Initial clinical experience.

PURPOSE: EPID-based in vivo dosimetry (IVD) has been implemented for stereotactic body radiotherapy treatments of non-small cell lung cancer to check both isocenter dose and the treatment reproducibility comparing EPID portal images. METHODS: 15 patients with lung tumors of small dimensions and treated with volumetric modulated arc therapy were enrolled for this initial experience. IVD tests supplied ratios R between in vivo reconstructed and planned isocenter doses. Moreover a γ-like analysis between daily EPID portal images and a reference one, in terms of percentage of points with γ-value smaller than 1, Pγ<1, and mean γ-values, γmean, using a local 3%-3mm criteria, was adopted to check the treatment reproducibility. Tolerance levels of 5% for R ratio, Pγ<1 higher than 90% and γmean lower than 0.67 were adopted. RESULTS: A total of 160 EPID images, two images for each therapy session, were acquired during the treatment of the 15 patients. The overall mean of the R ratios was equal to 1.005±0.014 (1 SD), with 96.9% of tests within±5%. The 2D image γ-like analysis showed an overall γmean of 0.39±0.12 with 96.1% of tests within the tolerance level, and an average Pγ<1 value equal to 96.4±3.6% with 95.4% of tests with Pγ<1>90%. Paradigmatic discrepancies were observed in three patients: a set-up error and a patient morphological change were identified thanks to CBCT image analysis whereas the third discrepancy was not fully justified. CONCLUSIONS: This procedure can provide improved patient safety as well as a first step to integrate IVD and CBCT dose recalculation.