An Innovative Approach to Scalp Segmentation in Pediatric Brain Radiotherapy: An Atlas-Based Study

PURPOSE/OBJECTIVE(S)

This study aims to develop an atlas-based method for segmentation of the scalp in pediatric patients that received brain radiotherapy. The study focuses on the development of a model that utilizes CT scans of pediatric medulloblastoma (MB) patients who underwent craniospinal-irradiation (CSI) and a boost in the posterior cranial fossa (PCF).

MATERIALS/METHODS

A team of experts created the Alopecia_Hope (A_H) contouring protocol on the CT scan using the 2018 EPTN consensus-based atlas and by defining for the manual adjustments the anatomic bone landmarks to differentiate between the scalp and the facial and neck skin. Using RayStation version 12A-SP1, the system was running his latest available software version at the time of study. Automated scripts were created to identify bone tissue and skin as a subtraction volume between bone and body. The soft tissue CT window was then manually used to increase or decrease the thickness of the skin, following the landmarks outlined in the protocol. The entire head scalp was defined as WScalp (WS), and a duplicate and reduced version was also defined as PCFScalp (PCFS). We randomly chose 40 patients to create both WS and PCF atlas with RayStation and 8 patients were used as testers for both volumes, the patients with major bone changes after neurosurgery were excluded. The contouring time was recorded, the mean time was calculated, and the contouring results were analyzed by experts. Standard similarity metrics of 3D DICE similarity coefficient and mean distance to agreement (MDA) were calculated.

RESULTS

A total of 52 patients were selected for the study, with a median contouring time of 19 minutes using the guidelines, the A_H protocol and automatic scripting. Three patients were excluded. Of the 8 testers, including both volumes (WS and PCFS), the mean contouring time for the expert operator was 17.5 min. While the contouring undergone by the automatic atlas was 11 min and the mean time of the expert correction was 4.5 min. Considering the work done by the atlas is in background, this resulted in a time savings of 80% for the operator. Table 1 contains mean and one standard deviation data for the metric, both WS and PCFS tested.

CONCLUSION

Atlas-based self-segmentation and the Alopecia_Hope protocol offer a more efficient and accurate method to identify specific areas of the scalp that may be affected by post-radiotherapy hair loss. This study demonstrates the effectiveness and efficiency in reducing radiotherapy workload and improving accuracy, with possible future application in the prevention of permanent alopecia and in improving the quality of life of patients undergoing whole brain radiotherapy.

Total marrow irradiation for second allogeneic hematopoietic stem cell transplantation in patients with advanced acute leukemia

BACKGROUND

Second allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option for patients with acute leukemia relapsing after a first HSCT. While a myeloablative (MA) conditioning regimen before the first HSCT is considered better than reduced intensity (RIC) in terms of disease control in acute leukemia patients, the optimal conditioning regimen for the second allogeneic HSCT remains controversial. The most important prognostic factors are the remission disease phase at the time of the second HSCT and more than 12 months from the first to the second HSCT. Total Marrow Irradiation (TMI) is an advanced high-precision radiation treatment that delivers therapeutic doses over extensively selected targets while substantially reducing radiation to vital organs compared to conventional Total Body Irradiation (TBI). Herein we report the results of a retrospective analysis on second allogeneic transplantation treated with TMI as a myeloablative conditioning regimen, intending to limit toxicity.

OBJECTIVE

We investigated the efficacy of a high dose per fraction TMI in combination with thiotepa, fludarabine and melphalan in 13 consecutive patients with acute leukemia relapsed after a first allogeneic HSCT treated between March 2018 and November 2021.

STUDY DESIGN

Donor type was haploidentical (HAPLO, n=10), unrelated (UD n=2), and HLA-identical sibling (SIB, n=1). The conditioning regimen consisted of TMI 8 Gy in 5 patients on day -8 -7 or TMI 12 Gy in 8 patients on day -9 -8 -7, plus Thiotepa 5 mg/Kg on day -6, Fludarabine 50 mg/mq on day -5 -4 -3, Melphalan 140 mg/mq on day -2. TMI was delivered in a hypofractionated daily single dose of 4 Gy for three consecutive fractions. The median age was 45 years (range, 19-70 years); 7 patients were in remission, and 6 had active disease at the time of the second allogeneic HSCT.

RESULTS

The median time to neutrophil counts of > 0.5×10e9/L was 16 days (range 13-22), and platelet counts of > 20×10e9/L were 20 days (range 14-34), respectively. All patients showed a complete donor chimerism on day 30 after the transplant. The cumulative incidence of grade I II acute GvHD (aGvHD) was 43%, and chronic GvHD (cGVHD) was 30%. The median follow-up was 1121 days (range 200-1540). Day +30 and +100 transplant-related mortality (TRM) was 0. Overall cumulative incidence of TRM, relapse rate, and disease free-survival (DFS) were respectively 27%,7%, and 67%.

CONCLUSIONS

This retrospective study showed the safety and efficacy of a hypofractionated TMI conditioning regimen in patients with acute leukemia receiving second HSCT with encouraging outcomes regarding engraftment, early toxicity, GvHD, and relapse.

Trends in incidence of invasive vaginal cancer in France from 1990 to 2018 and survival of recently diagnosed women - A population-based study

OBJECTIVE

The aim of this study was to analyze trends in the incidence of vaginal cancer in France over a 28-year period and to present survival for recently-diagnosed women.

METHODS

French cancer registries provided data on invasive vaginal cancers diagnosed from 1990 to 2015 and followed up through June 2018. Trends in incidence were analyzed using a Poisson model with a bidimensional penalized spline of age and year at diagnosis. Net survival analysis was restricted to recently-diagnosed cases (2010-2015) and used a novel approach based on a bidimensional penalized spline of age and time-since-diagnosis to model excess mortality hazard.

RESULTS

With 162 new cases estimated in France in 2018, vaginal cancer represented 0.9 % of genital cancers in French women. In 2018, the world population age-standardized incidence rate was 0.2 per 100,000 person-years, median age at diagnosis was 75 years. The standardized incidence rate decreased significantly by 3 % per year (95 % CI, -3.8; -2.2) between 1990 and 2018 (0.4 cases per 100,000 person-year in 1990, vs 0.2 in 2018). Age-standardized net survival at 1 and 5 years after diagnosis was respectively 74 % and 45 %.

CONCLUSIONS

This study confirms that vaginal cancer is still a rare malignancy in France with 5-year net survival that remains low. We observed a consistent decrease in the incidence rate between 1990 and 2018. It may be too early to attribute these trends to a positive impact of vaccination campaigns against hrHPV infection, since vaginal cancer mainly affects older women and HPV vaccination has only been available since the early 2000s, and only targets young girls.

High dose craniospinal irradiation as independent risk factor of permanent alopecia in childhood medulloblastoma survivors: cohort study and literature review

PURPOSE

Our aim was to determine the main risk factors related to the occurrence of permanent alopecia in childhood medulloblastoma (MB) survivors.

METHODS

We retrospectively analyzed the clinical features of all consecutive MB survivors treated at our institute. We divided the patients into 3 groups depending on the craniospinal irradiation (CSI) dose received and defined permanent alopecia first in terms of the skin region affected (whole scalp and nape region), then on the basis of the toxicity degree (G). Any relationship between permanent alopecia and other characteristics was investigated by a univariate and multivariate analysis and Odds ratio (OR) with confidence interval (CI) was reported.

RESULTS

We included 41 patients with a mean10-year follow-up. High dose CSI resulted as an independent factor leading to permanent hair loss in both groups: alopecia of the whole scalp (G1 p-value 0.030, G2 p-value 0.003) and of the nape region (G1 p-value 0.038, G2 p-value 0.006). The posterior cranial fossa (PCF) boost volume and dose were not significant factors at multivariate analysis neither in permanent hair loss of the whole scalp nor only in the nuchal region.

CONCLUSION

In pediatric patients with MB, the development of permanent alopecia seems to depend only on the CSI dose ≥ 36 Gy. Acute damage to the hair follicle is dose dependent, but in terms of late side effects, constant and homogeneous daily irradiation of a large volume may have a stronger effect than a higher but focal dose of radiotherapy.

P03.11.A Potential role of pre-radiotherapy MRI for target delineation in high-grade gliomas: a multicenter retro-prospective cohort study

Background

The optimal timing for target identification in high-grade glioma (HGG) remains unclear due to variability in the hyper-signal T2/FLAIR between MRI performed at diagnosis, post-surgery and at radiotherapy (RT) start. The aim of this study was to retrospectively confirm that RT planned on delayed MRI might allow to spare more normal tissue without decreasing local tumour control, in order to prospectively evaluate the best standard and advanced MRI and metabolic imaging sequences for clinical tumor volume (CTV) adaptation.

Material and Methods

We analyzed a retrospective cohort of consecutive patients with HGG treated from 2017 to 2020. All patients had a diagnostic MRI and another performed immediately post-surgery or pre-RT. Target volumes were contoured, based on T2/FLAIR, on diagnostic and post-surgery MRI in group A, while in group B on pre-RT MRI. We analyzed GTV and CTV volume, and the percentage increase between them. Moreover, we compared the two groups in terms of clinical-pathological characteristics and progression-free survival (PFS) and overall survival (OS). A prospective study, started on January 2022, has enrolled patients with HGG evaluated by advanced sequences MRI at diagnosis, post-surgery and pre-RT. In addition, some selected patients have undergone diagnostic DOPA-PET and pre-RT DOPA-PET. 2 MRI-guided contours have been performed for each patient: adapted on T2/FLAIR post-surgery and CTV-adapt on pre-RT, to assess study objectives.

Results

In retrospective cohort we analyzed 54 patients (25 group A, 29 group B). The median age of patients was 61 years (IQR 17,75), 93% had an ECOG PS of 0 or 1, 51 were symptomatic at diagnosis. Patients in group B had more frequently MGMT methylation (59 % vs. 28%, p=0.01) while less frequently frontal lobe involvement (60% vs. 24%, p=0.01). The median percentage increase between GTV and CTV was higher in group A than B: 431% (range 62%-7335%) vs 385% (range 53%-3174%), respectively. No significant difference in the pattern of relapse was observed, since >90% of disease recurrences were in-field in both groups. Median PFS and OS of the overall population were 9.5 months (95% CI 7 - 12) and 18.5 months (95% CI 16 - 24), respectively. Patients in group B had a significant better PFS as compared to those in group A (p=0.03), but similar OS. Nevertheless, imbalance in MTMT methylation status between the two groups was a major driver for PFS. Overall, 37 out of 51 patients had improvement in neurological symptoms (p<0.001), with no difference between the two groups (p=0.54).

Conclusion

Our data suggest that CTV adaptation to pre-RT T2/FLAIR may allow reducing RT volume, without affecting symptoms relieving and disease control. Results from the prospective study will help identifying the best adaptation of CTV guided by T2/FLAIR, advanced MRI sequences and metabolic imaging, in order to optimize efficacy and safety of treatment planning.

Biomass-to-electricity: analysis and optimization of the complete pathway steam explosion--enzymatic hydrolysis--anaerobic digestion with ICE vs SOFC as biogas users

The paper deals with the energy analysis and optimization of a complete biomass-to-electricity energy pathway, starting from raw biomass towards the production of renewable electricity. The first step (biomass-to-biogas) is based on a real pilot plant located in Environment Park S.p.A. (Torino, Italy) with three main steps ((1) impregnation; (2) steam explosion; (3) enzymatic hydrolysis), completed by a two-step anaerobic fermentation. In the second step (biogas-to-electricity), the paper considers two technologies: internal combustion engines and a stack of solid oxide fuel cells. First, the complete pathway has been modeled and validated through experimental data. After, the model has been used for an analysis and optimization of the complete thermo-chemical and biological process, with the objective function of maximization of the energy balance at minimum consumption. The comparison between ICE and SOFC shows the better performance of the integrated plants based on SOFC.

Manchester triage in acute pulmonary embolism: can it unmask the grand impersonator?

BACKGROUND

Acute pulmonary embolism (PE) is associated with high mortality risk. Early diagnosis is difficult because of non-specific clinical presentation and delay in imaging confirmation. Manchester Triage (MT) prioritises patients on the basis of illness severity and potentially recognises those with higher mortality risk. No studies of the role and impact of MT on rapid PE diagnosis and in-hospital mortality (IHM) have been carried out.

OBJECTIVE

To assess the appropriateness of MT in this set of patients presenting acutely to the emergency department (ED), and to determine whether it assists in a rapid diagnosis, acts as a protective triage tool and affects short-term mortality.

METHODS

Single-centre retrospective study of 176 consecutive patients with PE, assessed by MT in the ED between January 2006 and October 2010 (mean age 70.5±15.7 years, 38.6% men). The primary outcome measure was all-cause IHM.

RESULTS

IHM was seen in 30 (17%) patients. More than half of the patients with PE (54%) were classified as target time for first medical observation (MOb) ≤10 min. 73.3% of IHM occurred in this group (p=0.020) with several increased markers of illness severity. MOb ≤10 min was not associated with faster PE imaging confirmation. The average door-to-diagnosis time (PEDx) was 26.8±36.8 h and PEDx >17.0 h was associated with higher IHM (p=0.017). On multivariate analysis, thrombolysis and MOb ≤10 min were included in an IHM predictor model.

CONCLUSION

MT has high sensitivity in identifying patients with PE at risk. Those patients assigned as MOb ≤10 min have increased markers of illness severity and higher IHM. MT acts as a protective system in this challenging set and should be used as a patient's first assessment, aiding the emergency medical team to recognise those in need of urgent assessment and treatment.

Parental history of premature myocardial infarction is a stronger predictor of increased carotid intima-media thickness than parental history of hypertension

An increased carotid intima-media thickness (IMT) is detectable in young subjects with parental history of premature myocardial infarction (PHPMI) or hypertension (PHH). In this study we evaluated if PHPMI and PHH exert a different influence on carotid IMT and if their conjunction produces additive effects. High-resolution B-mode ultrasonographic evaluation of common carotid artery IMT was acquired from 48 subjects without PHPMI and PHH (22 males, 26 females; mean age 22.1±4.9 years; controls), 24 age- (±1 year) and sex-matched subjects with PHH without PHPMI (PHH-positive/PHPMI-negative subjects), 24 age- and sex-matched subjects with PHPMI without PHH (PHH-negative/PHPMI-positive subjects) and 24 age- and sex-matched subjects with both PHPMI and PHH (PHH/PHPMI-positive subjects). Lipid profile, resting blood pressure, smoking behaviour and body mass index (BMI) were also assessed. Carotid IMT was smaller in controls (0.41±0.07mm) compared to PHH-positive/PHPMI-negative subjects (0.47±0.10, p=0.023), to PHH-negative/PHPMI-positive subjects (0.54±0.11, p<0.001) and to PHH/PHPMI-positive subjects (0.52±0.10mm, p<0.001). Carotid IMT was greater in PHH-negative/PHPMI-positive (p=0.006) and in PHH/PHPMI-positive (p=0.031) than in PHH-positive/PHPMI-negative subjects. No difference in carotid IMT was evident between PHH-negative/PHPMI-positive and PHH/PHPMI-positive subjects (p=0.549). In the comparison among subjects using multiple regression analysis, only PHPMI, age and BMI were independently associated with carotid IMT. In healthy young subjects with PHPMI and/or PHH, carotid IMT is increased. PHPMI is a stronger predictor of increased carotid IMT than PHH. PHH in conjunction with PHPMI does not add any further detrimental effect on carotid IMT.

Subclinical atherosclerosis and genetic risk markers in healthy offspring of patients with premature myocardial infarction

AIM

Healthy young subjects with parental history of premature myocardial infarction (PHPMI) might constitute a privileged population for the study of genetic risk markers (GRM) for atherosclerosis. Aim of this study was to evaluate which, if any, GRM atherosclerosis-associated in previous studies has increased prevalence in a selected population.

METHODS

Twenty-four healthy young subjects (12 males and 12 females; mean age 18.0±8.0 years) with PHPMI and 24 age- (±1 year), sex-matched healthy subjects without PHPMI were enrolled in the study. They underwent: 1) fasting measurement of lipid profile, resting blood pressure and body mass index; 2) high resolution B-mode ultrasonographic evaluation of common carotid artery intima-media thickness (IMT); 3) evaluation of Single Nucleotide Polymorphisms (SNPs) for six candidate genes associated with preclinical atherosclerosis.

RESULTS

Compared to controls, subjects with PHPMI had increased IMT of common carotid arteries (mean of combined sites: 0.535±0.171 mm versus 0.432± 0.133 mm in controls, P=0.017). Offspring of coronary patients showed an increased prevalence of the unfavourable chemochine (C-X-C motif) ligand 12 (CXCL12) SNP risk genotype (P=0.047).

CONCLUSION

In healthy young subjects with PHPMI there is an increased prevalence of the unfavorable CXCL12 SNP risk genotype.

[Feasibility of week surgery model in general surgery]

Progress in medical technology and the research in cost-effectiveness have provided an implementation on new general surgery models. Week Surgery model is a maximum 5 days stay surgical unit which represents an important contribution to surgical therapeutic strategies, allowing an excellent compromise between safety, convenience for the patient and economic savings for health care structures. This model represent an excellent compromise between elective and emergency care and thus allow to improve patients flow across the week, a most efficient bed utilisation and reallocating hospital workloads. With the aim of testing the feasibility of the application of Week Surgery model was carried out a seven-years retrospective study (2000-2006) among Veneto Region public hospitals. Results suggest that week surgery model can be considered a valid and achievable alternative organisation compared to conventional hospitalization: 61% of patient undenrwent elective surgery were discharged in less than 5 days.

[Discharge against medical advice in Veneto Region]

Discharge against medical advice (DAMA) may put patients at risk of adverse health outcomes and often generate hospital readmission. A retrospective case-control study (2000-2004) of all DAMA in Veneto Region hospitals was carried out to determine the baseline characteristics of patients who leaves hospital. During the 5-years study period, the overall DAMA rates were 0.8 from ordinary hospitalization and 0.2 from daily. Prediction of patients at risk of DAMA may be possible with several defined variables and this analysis represent an instrument that should facilitate the development of successful strategies to reduce DAMA for high-risk patients.