Analysis of intra-fractional positioning correction performed by cone beam computed tomography in SBRT treatments

PURPOSE

This study aims to evaluate the positioning correction extracted from Intra-fraction Cone Beam (IF-CBCT) images obtained during Stereotactic Body Radiotherapy (SBRT) treatments, and to assess whether its magnitude justifies its acquisition. In addition, the results obtained in lung, liver, and pancreas SBRTs with two deep inspiration breath-hold systems (DIBH), and for prostate with/without ultrasound (US) monitoring were compared.

METHODS

1449 treatments, performed with two linear accelerators (LINACs) were retrospectively analyzed. DIBH were performed either with a spirometry-based device or a surface-guidance system and one LINAC was equipped with US monitoring system for prostate. Significance tests were used to account for differences between units.

RESULTS

Group systematic error (M) was approximately -0.7 mm for DIBH treatments in superior-inferior (SI) direction with no difference (p > 0.7) between LINACs. Moreover, there was a SI difference of 0.5 mm for prostate treatments (p = 0.008), in favor of the US monitored one. In anterior-posterior (AP) direction, only liver treatments exhibited differences between LINACs, with the spirometer-based system being 0.8 mm inferior (p = 0.003). M<0.4 mm in left-right (LR) direction was found for all locations and LINACs. The spirometer-based system resulted in lower standard deviation of systematic and random errors in most components and locations, with a greater effect observed in liver SBRTs.

CONCLUSIONS

The corrections made with IF-CBCT during SBRT treatments were not negligible. Both DIBH systems were effective in managing respiratory movements. However, the spirometry-based system was slightly more accurate. In addition, US monitoring of the prostate appeared to be useful in reducing target shift.

Formation of intraneuronal iron deposits following local release from nanostructured silica injected into rat brain parenchyma

Nanostructured materials with controllable properties have been used to cage and release various types of compounds. In the present study, iron-loaded nanostructured sol-gel SiO2-Fe materials were prepared and injected into the rat brain to develop a method for gradual iron delivery into the neurons with the aims to avoid acute iron toxicity and develop an animal model of gradual, metal-induced neurodegeneration. Nanoparticles were prepared by the traditional method of hydrolysis and condensation reactions of tetraethyl orthosilicate at room temperature and subsequent heat treatment at 200 °C. FeSO4 was added in situ during the silica preparation. The resulting materials were characterized by UV-VIS and infrared spectroscopies, X-ray diffraction, and N2 adsorption-desorption. An in vitro ferrous sulfate release test was carried out in artificial cerebrospinal fluid as the release medium showing successful ferrous sulfate loading on nanostructured silica and sustained iron release during the test time of 10 h. Male Wistar rats administered with SiO2-Fe nanoparticles in the substantia nigra pars compacta (SNpc) showed significant intraneuronal increase of iron, in contrast to the animals administered with FeSO4 that showed severe neuronal loss, 72 h post-treatment. Both treatments induced lipid fluorescent product formation in the ventral midbrain, in contrast to iron-free SiO2 and PBS-only injection controls. Circling behavior was evaluated six days after the intranigral microinjection, considered as a behavioral end-point of brain damage. The apomorphine-induced ipsilateral turns in the treated animals presented significant differences in relation to the control groups, with FeSO4 administration leading to a dramatic phenotype, compared to a milder impact in SiO2-Fe administrated animals. Thus, the use of SiO2-Fe nanoparticles represents a slow iron release system useful to model the gradual iron-accumulation process observed in the SNpc of patients with idiopathic Parkinson's disease.

Real-world effectiveness and safety of stereotactic body radiotherapy for liver metastases with different respiratory motion management techniques

PURPOSE

Stereotactic body radiotherapy (SBRT) has been firmly established as a treatment choice for patients with oligometastases, as it has demonstrated both safety and efficacy by consistently achieving high rates of local control. Moreover, it offers potential survival benefits for carefully selected patients in real-world clinical settings.

METHODS

Between January 2008 and May 2020, a total of 149 patients (with 414 liver metastases) received treatment. The Active Breathing Coordinator device was used for 68 patients, while respiratory gating was used for 65 and abdominal compression was used for 16 patients. The most common histological finding was colorectal adenocarcinoma, with 37.6% of patients having three or more metastases, and 18% having two metastases. The prescribed dose ranged from 36 to 60 Gy, delivered in 3-5 fractions.

RESULTS

Local control rates at 2 and 3 years were 76.1% and 61.2%, respectively, with no instances of local recurrence after 3 years. Factors negatively impacting local control included colorectal histology, lower prescribed dose, and the occurrence of new liver metastases. The median overall survival from SBRT was 32 months, with the presence of metastases outside the liver and the development of new liver metastases after SBRT affecting survival. The median disease-free survival was 10 months. No substantial differences in both local control and survival were observed between the respiratory motion control techniques employed. Treatment tolerance was excellent, with only one patient experiencing acute grade IV thrombocytopenia and two patients suffering from ≥ grade II chronic toxicity.

CONCLUSION

For radical management of single or multiple liver metastases, SBRT is an effective and well-tolerated treatment option. Regardless of the technology employed, experienced physicians can achieve similarly positive outcomes. However, additional studies are required to elucidate prognostic factors that can facilitate improved patient selection.

Improved clinical utility of preimplantation genetic testing through the integration of ploidy and common pathogenic microdeletions analyses

STUDY QUESTION

Can chromosomal abnormalities beyond copy-number aneuploidies (i.e. ploidy level and microdeletions (MDs)) be detected using a preimplantation genetic testing (PGT) platform?

SUMMARY ANSWER

The proposed integrated approach accurately assesses ploidy level and the most common pathogenic microdeletions causative of genomic disorders, expanding the clinical utility of PGT.

WHAT IS KNOWN ALREADY

Standard methodologies employed in preimplantation genetic testing for aneuploidy (PGT-A) identify chromosomal aneuploidies but cannot determine ploidy level nor the presence of recurrent pathogenic MDs responsible for genomic disorders. Transferring embryos carrying these abnormalities can result in miscarriage, molar pregnancy, and intellectual disabilities and developmental delay in offspring. The development of a testing strategy that integrates their assessment can resolve current limitations and add valuable information regarding the genetic constitution of embryos, which is not evaluated in PGT providing new level of clinical utility and valuable knowledge for further understanding of the genomic causes of implantation failure and early pregnancy loss. To the best of our knowledge, MDs have never been studied in preimplantation human embryos up to date.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort analysis including blastocyst biopsies collected between February 2018 and November 2021 at multiple collaborating IVF clinics from prospective parents of European ancestry below the age of 45, using autologous gametes and undergoing ICSI for all oocytes. Ploidy level determination was validated using 164 embryonic samples of known ploidy status (147 diploids, 9 triploids, and 8 haploids). Detection of nine common MD syndromes (-4p=Wolf-Hirschhorn, -8q=Langer-Giedion, -1p=1p36 deletion, -22q=DiGeorge, -5p=Cri-du-Chat, -15q=Prader-Willi/Angelman, -11q=Jacobsen, -17p=Smith-Magenis) was developed and tested using 28 positive controls and 97 negative controls. Later, the methodology was blindly applied in the analysis of: (i) 100 two pronuclei (2PN)-derived blastocysts that were previously defined as uniformly euploid by standard PGT-A; (ii) 99 euploid embryos whose transfer resulted in pregnancy loss.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The methodology is based on targeted next-generation sequencing of selected polymorphisms across the genome and enriched within critical regions of included MD syndromes. Sequencing data (i.e. allelic frequencies) were analyzed by a probabilistic model which estimated the likelihood of ploidy level and MD presence, accounting for both sequencing noise and population genetics patterns (i.e. linkage disequilibrium, LD, correlations) observed in 2504 whole-genome sequencing data from the 1000 Genome Project database. Analysis of phased parental haplotypes obtained by single-nucleotide polymorphism (SNP)-array genotyping was performed to confirm the presence of MD.

MAIN RESULTS AND THE ROLE OF CHANCE

In the analytical validation phase, this strategy showed extremely high accuracy both in ploidy classification (100%, CI: 98.1-100%) and in the identification of six out of eight MDs (99.2%, CI: 98.5-99.8%). To improve MD detection based on loss of heterozygosity (LOH), common haploblocks were analyzed based on haplotype frequency and LOH occurrence in a reference population, thus developing two further mathematical models. As a result, chr1p36 and chr4p16.3 regions were excluded from MD identification due to their poor reliability, whilst a clinical workflow which incorporated parental DNA information was developed to enhance the identification of MDs. During the clinical application phase, one case of triploidy was detected among 2PN-derived blastocysts (i) and one pathogenic MD (-22q11.21) was retrospectively identified among the biopsy specimens of transferred embryos that resulted in miscarriage (ii). For the latter case, family-based analysis revealed the same MD in different sibling embryos (n = 2/5) from non-carrier parents, suggesting the presence of germline mosaicism in the female partner. When embryos are selected for transfer based on their genetic constitution, this strategy can identify embryos with ploidy abnormalities and/or MDs beyond aneuploidies, with an estimated incidence of 1.5% (n = 3/202, 95% CI: 0.5-4.5%) among euploid embryos.

LIMITATIONS, REASONS FOR CAUTION

Epidemiological studies will be required to accurately assess the incidence of ploidy alterations and MDs in preimplantation embryos and particularly in euploid miscarriages. Despite the high accuracy of the assay developed, the use of parental DNA to support diagnostic calling can further increase the precision of the assay.

WIDER IMPLICATIONS OF THE FINDINGS

This novel assay significantly expands the clinical utility of PGT-A by integrating the most common pathogenic MDs (both de novo and inherited ones) responsible for genomic disorders, which are usually evaluated at a later stage through invasive prenatal testing. From a basic research standpoint, this approach will help to elucidate fundamental biological and clinical questions related to the genetics of implantation failure and pregnancy loss of otherwise euploid embryos.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. S.C., M.F., F.C., P.Z., I.P., L.G., C.P., M.P., D.B., J.J.-A., D.B.-J., J.M.-V., and C.R. are employees of Igenomix and C.S. is the head of the scientific board of Igenomix. A.C. and L.P. are employees of JUNO GENETICS. Igenomix and JUNO GENETICS are companies providing reproductive genetic services.

TRIAL REGISTRATION NUMBER

N/A.

Cell-free DNA analysis in preimplantation genetic testing

Detection of chromosomal aneuploidies and monogenic disorders in preimplantation embryos is essential for selecting the best embryo for transfer during in vitro fertilization (IVF) to achieve a healthy pregnancy. Preimplantation genetic testing (PGT) is typically performed on preimplantation embryos to select a genetically normal embryo for transfer. A trophectoderm (TE) biopsy is necessary for PGT; this is an invasive procedure to the embryo that requires specialized equipment and highly trained embryologists, resulting in high costs associated with IVF treatment. Moreover, the biopsy procedure may increase the likelihood of developing pregnancy complications such as preeclampsia and hypertensive disorders. Therefore, there is a need for non-invasive embryo screening strategies. The presence of cell-free DNA (cfDNA) in the embryo culture medium presents an opportunity to screen for genetic abnormalities. cfDNA is released by embryos in the latter stages of preimplantation development, and its analysis has been proposed as a non-invasive approach for PGT. Here, we review studies reporting concordance rates between cfDNA and TE biopsies, or whole blastocysts (WB), in couples undergoing PGT. Non-invasive PGT results are promising for aneuploidy detection, with some early evidence of successful clinical application. Further research is required to explore its application for the detection of structural rearrangements and monogenic disorders.

ESHRE PGT Consortium data collection XXI: PGT analyses in 2018

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN SIZE DURATION

The data for PGT analyses performed between 1 January 2018 and 31 December 2018 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform, which is based on genetic analysis and has been in use since 2016.

PARTICIPANTS/MATERIALS SETTING METHODS

Data on biopsy method, diagnostic technology, and clinical outcome were submitted by 44 centres. Records with analyses for more than one PGT for monogenic disorders (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR), or with inconsistent data regarding the PGT modality, were excluded. All transfers performed within 2 years after the analysis were included, enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2018 covers a total of 1388 analyses for PGT-M, 462 analyses for PGT-SR, 3003 analyses for PGT for aneuploidies (PGT-A), and 338 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 19% in 2016-2017 to 33% in 2018), is status quo for PGT-SR (from 30% in 2016-2017 to 33% in 2018) and has become the most used biopsy stage for PGT-A (from 87% in 2016-2017 to 98% in 2018) and for concurrent PGT-M/SR with PGT-A (96%). The use of comprehensive, whole-genome amplification (WGA)-based diagnostic technology showed a small decrease for PGT-M (from 15% in 2016-2017 to 12% in 2018) and for PGT-SR (from 50% in 2016-2017 to 44% in 2018). Comprehensive testing was, however, the main technology for PGT-A (from 93% in 2016-2017 to 98% in 2018). WGA-based testing was also widely used for concurrent PGT-M/SR with PGT-A, as a standalone technique (74%) or in combination with PCR or FISH (24%). Trophectoderm biopsy and comprehensive testing strategies are linked with higher diagnostic efficiencies and improved clinical outcomes per embryo transfer.

LIMITATIONS REASONS FOR CAUTION

The findings apply to the data submitted by 44 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

The Consortium datasets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTERESTS

The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

P-020 Influence of vanadium and lead in seminal fluid on assisted reproductive techniques

Study question

In recent decades there has been an increase in environmental contaminants than can affect assisted reproduction techniques. We analyze the influence of vanadium (V) and lead (Pb) on these results.

Summary answer

Higher seminal fluid V levels affect fertilization rate (FR). Higher Pb and V levels decrease embryo cleavage rate (CR).

What is known already

Some animal studies have shown that V produces toxicity in the male reproductive system through oxidative stress, and this leads to decreases sperm count and motility, as well increased concentration of abnormal sperm.

Pb is one of the main pollutants and, it accumulates in the male reproductive organs, deteriorates the quality of semen, increases the frequency of spontaneous abortion and male infertility. And it has also been seen that it inhibits sperm functions in vitro, although its mechanism of action is still unknown.

Study design, size, duration

A prospective study was conducted in 102 males, with a mean age of 38.0 ± 5.7, attended successively for initial evaluation, in the Human Reproduction Unit of the Hospital Universitario de Canarias, between february and april 2018, who underwent a semen analysis and metal detection and, subsequently, an IVF/ICSI treatment during years 2019 and 2020 (n = 92). The relationship between the presence of metals and the results of ART has been established.

Participants/materials, setting, methods

We included two groups based on semen parameters: 41 patients with pathological spermiograms (40.2%), while the remaining 61 (59.8%) had a normal semen analysis and constituted the control group.The study of seminal parameters was performed according to the WHO guidelines. The metals analysis was carried out in the Toxicology Area of the Universidad de La Laguna, using the digestion for microwave method. Metal measurement was performed using inductively coupled plasma optical emission spectrometry (ICP-OES).

Main results and the role of chance

In our study we have observed 79.4% of patients have V in semen. Significant differences have been found in the concentration of V in semen (t100=1.988, p = 0.05), is higher in patients who drink alcohol (0.51± 0.40 mg/Kg) than in abstinent patients (0.35± 0.30 mg/Kg).

The group with FR above 75% presented lower V values compared to those with rates below 75% (p = 0.039). Within this last group, 33.3% present V values higher than 0.7 mg / kg compared to 15.8% who present it in the group with FR greater than 75% (OR = 2.67 CI95% 1.01, 7.52; p = 0.048).

A statistical relationship was found between CR and Pb and V. Those who did not reach 100% CR presented higher Pb values (p = 0.052). Of them, 63.6% presented Pb compared to 38.5% in the group reaching 100% division. This same relationship was observed for V, with higher values in the group that did not reach 100% (p = 0.032), and V being present in 90.9% of the samples compared to 79.5% in the group reaching 100%.

Limitations, reasons for caution

The limitation of this study was the volume of semen that could be obtained for the metal detection, only 0.5 ml. This was because the semen sample was used at the same time to make a diagnosis of infertility though a spermiogram

Wider implications of the findings

The determination of metals in semen opens a new field in the study of infertility, and many cases of unknown infertility could due to metal presence or absence in seminal fluid, with the option of performing several treatments to correct these possible anomalies.

Trial registration number

not applicable

P-551 High concordance of the embryonic cell-free DNA with the inner cell mass: impact of blastocyst quality, patient age and mode of fertilization

Study question

Does the embryonic cell-free DNA (cfDNA) in the culture medium represent the chromosomal content of the inner cell mass (ICM)? Which factors impact concordance rates?

Summary answer

There is high ploidy concordance between ICM biopsies and embryonic cfDNA. This value is independent of female age, insemination technique and embryo quality.

What is known already

The existence of embryonic cfDNA in spent blastocyst medium (SBM) has been confirmed in recent studies, opening a new era of possibilities for non-invasive preimplantation genetic testing for aneuploidy (niPGT-A). High concordance rates of cfDNA with trophectoderm (TE) biopsies and with whole blastocysts have been reported. However, the compartment(s) from where this DNA originates remain unclear. Both TE and ICM are potential sources, but, at the moment, the origin of this cfDNA is unknown as well as the mechanisms underlying its secretion into the medium.

Study design, size, duration

We carried out a prospective study to investigate the concordance of cfDNA with the corresponding TE and ICM biopsies. 141 day-6/7 blastocysts were donated for research after written informed consent signature for the project approved by the Ethics Committee. Embryos underwent TE biopsy and SBM collection in the same PGT-A cycle. ICM biopsy in thawed blastocysts was performed after TE biopsy diagnosis. cfDNA, TE and ICM biopsies were analyzed from January 2019 to November 2021.

Participants/materials, setting, methods

Embryos were cultured in routine conditions up to day 4. They were then washed and transferred to a new 10μl culture medium droplet. On day 6, SBM was collected and frozen at -20 °C; and blastocyst biopsy and vitrification were performed. Subsequently, blastocysts were thawed and ICM biopsy was conducted. All samples were analyzed by NGS (Ion ReproSeq PGS kit, ThermoFisher Scientific) and the results were analyzed with customized algorithms for TE, ICM and cfDNA.

Main results and the role of chance

In combination, the three sample types (cfDNA, ICM and TE) were informative in 81.6% of the blastocysts (115/141).

Considering the ICM as the reference, ploidy concordance (i.e. being both euploid or aneuploid) for cfDNA was 86.1% (99/115) and for TE was 89.6% (103/115), without statistical difference. False positive rates were similar for cfDNA and for TE biopsies (6.1% and 9.6%, respectively), and false negative rates were not significantly different, but higher in cfDNA (7.8%) than in TE (0.9%), due to potential contamination with maternal DNA. Ploidy concordance between embryo cfDNA and TE biopsies was 89.6% (103/115).

When the results were stratified by female age (≤37 or &gt; 37 years), insemination technique (ICSI or IVF), blastocyst expansion degree (expanded, hatching or fully hatched), and ICM/TE quality (A or B), the informativity of the cfDNA was very similar between the different groups and ranged from 83.7% to 100%. Nevertheless, there were subtle differences for ICM-cfDNA ploidy concordance. It was slightly increased for the older female age group (88.3% vs 83.6% female age ≤37) as well as for ICSI (89.7% vs 82.5% in IVF) and for ICM quality B (88.4% vs 80.0% for ICM A). None of those differences reached statistical significance.

Limitations, reasons for caution

When stratifying according to the different criteria, the sample size analyzed was too small to draw strong conclusions. Therefore, more studies, with bigger sample size, are needed to replicate the results.

Wider implications of the findings

The embryonic cfDNA released to the culture medium provides information of the overall blastocyst chromosomal constitution, as suggested by the high ploidy concordance rates reported between ICM and cfDNA. This supports the use of niPGT-A as an alternative to other invasive aneuploidy detection methods that require a biopsy.

Trial registration number

ClinicalTrials.gov. ID NCT03520933

O-042 ESHRE good practice recommendations on chromosomal mosaicism

The implementation of high-resolution genome-wide methods, usually next-generation sequencing-based, in preimplantation genetic testing (PGT), has led to the frequent detection of embryos with chromosomal mosaicism (whole chromosome and/or segmental aberrations). Despite a growing series of papers showing the birth of healthy babies following the transfer of embryos indicating mosaicism on PGT-A analysis - albeit with lower implantation rates and higher miscarriage rates in comparison with euploid embryo transfer - many questions remain, making it difficult to decide on how to handle chromosomally mosaic embryos in the clinic.

A dedicated ESHRE working group developed good practice recommendations on how to manage chromosomal mosaicism in clinical practice. The recommendations were formulated based on the expert opinion of the working group while taking into consideration the published data and outcomes of a survey on current practices in 239 PGT laboratories and ART clinics, mostly within Europe, Asia and America. The recommendations with regards to detection and management of chromosomal mosaicism were developed following the manual for development of ESHRE good practice recommendations with a stakeholder review of the paper on the ESHRE website. In addition to the recommendations, the working group identified missing information and scientific questions, which should guide further research in PGT, with relevance to the occurrence, detection and impact of chromosomal mosaicism.

Trial registration number:

O-041 Data from the ESHRE PGT consortium – year 2020

Study question

Which are the trends shown in data collection XXII of the European Society of Human Reproduction and Embryology (ESHRE) PGT Consortium compared with previous years?

Summary answer

Data collection XXII, year 2020, represents valuable data on PGT activity in (mainly) Europe and reports on the main trends observed, being the further expansion of comprehensive testing technology in PGT-SR and PGT-A.

What is known already

The ESHRE PGT Consortium was set up in 1997 and from that time has been collecting data on PGT and PGT-A. The PGT database comprises the world’s largest collection of PGT / PGT-A data providing a valuable resource for data mining and for following trends in PGT practice. So far, up to the year 2015, data collections were carried out in a retrospective data way, from 2016 onwards a prospective cycle-by-cycle data collection was in place.

Study design, size, duration

As the nature of PGT/ PGT-A treatments has changed significantly over the last years and IVF cycle management and genetic analysis techniques are getting more complex, ESHRE uses an online data collection system in which data are collected prospectively from oocyte retrieval to analysis, embryo transfer and pregnancy / live birth. Data are collected cycle by cycle on a voluntary basis.

Participants/materials, settings, method

For the 2020 data, individual centres (37) from 20 countries directly entered the data into the PGT database through software developed by ESHRE. Data were analysed at ESHRE headquarters and include all aspects of PGT/PGT-A cycles.

Main results and the role of chance

The Consortium has analysed the PGT analyses (n = 2809) performed in 2020. The indications for PGT included inherited chromosomal abnormalities (n = 331 analyses), monogenic disorders (n = 987 analyses), aneuploidy testing for infertility (n = 1417 analyses) or combinations of the above (n = 74 analyses). In addition, 704 clinical pregnancies and 335 deliveries have been analysed in detail. The methods used for biopsy were polar body (2%), cleavage stage biopsy (20%) and blastocyst biopsy (78%), showing a further increase of blastocyst biopsy compared to 2019. The methodology used for diagnosis is what is evolving most over the last years, with data set XXII (2020) showing around 4% of FISH, 28% of PCR and 68% of WGA. Within WGA 95% of the analysis were done using NGS, in 4% of the cases SNP arrays were used and in 1% array-CGH was used. The overall clinical pregnancy rate is about 25% per analysis. The baby data show that it is difficult for most centres to have a detailed follow-up.

Limitations, reasons for caution

The findings apply to the 37 participating centres and may not represent worldwide trends in PGT. Data were collected prospectively, but details of the follow-up on PGT pregnancies and babies born were limited.

Wider implications of the findings

The ESHRE PGD Consortium continues its activities as an important forum for PGT practitioners to share data and exchange experiences. The information extracted from the data collections helps to monitor quality issues in PGT and survey the introduction and effectiveness of new PGT technologies and methods.

Trial registration number

Could pulmonary low-dose radiation therapy be an alternative treatment for patients with COVID-19 pneumonia? Preliminary results of a multicenter SEOR-GICOR nonrandomized prospective trial (IPACOVID trial)

PURPOSE

To evaluate the efficacy and safety of lung low-dose radiation therapy (LD-RT) for pneumonia in patients with coronavirus disease 2019 (COVID-19).

MATERIALS AND METHODS

Inclusion criteria comprised patients with COVID-19-related moderate-severe pneumonia warranting hospitalization with supplemental O2 and not candidates for admission to the intensive care unit because of comorbidities or general status. All patients received single lung dose of 0.5 Gy. Respiratory and systemic inflammatory parameters were evaluated before irradiation, at 24 h and 1 week after LD-RT. Primary endpoint was increased in the ratio of arterial oxygen partial pressure (PaO2) or the pulse oximetry saturation (SpO2) to fractional inspired oxygen (FiO2) ratio of at least 20% at 24 h with respect to the preirradiation value.

RESULTS

Between June and November 2020, 36 patients with COVID-19 pneumonia and a mean age of 84 years were enrolled. Seventeen were women and 19 were men and all of them had comorbidities. All patients had bilateral pulmonary infiltrates on chest X‑ray. All patients received dexamethasone treatment. Mean SpO2 pretreatment value was 94.28% and the SpO2/FiO2 ratio varied from 255 mm Hg to 283 mm Hg at 24 h and to 381 mm Hg at 1 week, respectively. In those who survived (23/36, 64%), a significant improvement was observed in the percentage of lung involvement in the CT scan at 1 week after LD-RT. No adverse effects related to radiation treatment have been reported.

CONCLUSIONS

LD-RT appears to be a feasible and safe option in a population with COVID-19 bilateral interstitial pneumonia in the presence of significant comorbidities.

Low-dose radiation therapy for hand osteoarthritis: shaking hands again?

BACKGROUND

Hand osteoarthritis (HOA) is one of the most common causes of pain and functional disability in western countries and there is still no definitive cure. Low-dose radiation therapy (LDRT) has anti-inflammatory properties that have shown to be effective in the symptomatic relief of various degenerative musculoskeletal disorders. We designed a clinical protocol using LDRT for symptomatic HOA and present results and tolerance in the first 100 patients included.

MATERIALS AND METHODS

Between April 2015 and March 2021, 100 patients with a median age of 60 were treated. Fifty-seven patients suffering from proximal/distal interphalangeal joint pain, 40 patients with thumb arthritis, 2 patients with radiocarpal joint affection and 1 patient with metacarpophalangeal joint pain were enrolled. LDRT comprised of 6 fractions of 0.5-1 Gy on every other day up to a total dose of 3-6 Gy. Clinical response was evaluated according to the visual analog scale (VAS) for pain level and the von Pannewitz score (VPS) for joint functionality. Any patients not achieving subjective adequate pain relief after 8 weeks of treatment were offered a second identical LDRT course.

RESULTS

With a median follow-up of 10.5 months (range 7.55-12.45), 94% reported an improvement in the pain, with a significant reduction in the VAS level after 3, 6 and 12 months (p < 0.001). Sixty-three patients needed a second course of treatment at a median time interval of 12 weeks (range 9-14). The mean VAS score before treatment was 8 (range 3-10). After treatment, it was 5 (range 1-10). After 3, 6 and 12 months, the mean VAS scores were 4 (range 0-9), 3 (range 0-9) and 3.5 (range 0-9), respectively. Seventy patients reported functionality improvements after LDRT according to the von Pannewitz score. No acute or late complications were observed.

CONCLUSION

LDRT appears to be safe and useful for HOA and is associated with good rates of pain relief and functionality improvements. However, further studies are necessary to confirm these promising results.

O-009 Data from the ESHRE PGT consortium – year 2019

Study question

Which are the trends shown in data collection XXI of the European Society of Human Reproduction and Embryology (ESHRE) PGT Consortium compared with previous years?

Summary answer

Data collection XXI, year 2019, represents valuable data on PGT activity in (mainly) Europe and reports on the main trends observed, being the further expansion of comprehensive testing technology in PGT-SR and PGT-A.

What is known already

The ESHRE PGT Consortium was set up in 1997 and from that time has been collecting data on PGT and PGT-A. The PGT database comprises the world’s largest collection of PGT / PGT-A data providing a valuable resource for data mining and for following trends in PGT practice. So far, up to the year 2015, data collections were carried out in a retrospective data way, from 2016 onwards a prospective data collection was in place.

Study design, size, duration

As the nature of PGT/ PGT-A treatments has changed significantly over the last years and IVF cycle management and genetic analysis techniques are getting more complex, ESHRE uses an online data collection system in which data are collected prospectively from oocyte retrieval to analysis, embryo transfer and pregnancy / live birth. Data are collected cycle by cycle on a voluntary basis.

Participants/materials, settings, method

For the 2019 data, individual centres (31) from 19 countries directly entered the data into the PGT database through software developed by ESHRE. Data were analysed at ESHRE headquarters and include all aspects of PGT/PGT-A cycles.

Main results and the role of chance

The Consortium has analysed the PGT analyses (n = 2735) performed in 2019. The indications for PGT included inherited chromosomal abnormalities (n = 253 analyses), monogenic disorders (n = 1105 analyses), aneuploidy testing for infertility (n = 1111 analyses) or combinations of the above (n = 266 analyses). In addition, 662 clinical pregnancies and 216 deliveries have been analysed in detail. The methods used for biopsy were polar body (2%), cleavage stage biopsy (35%) and blastocyst biopsy (61%; comparable with data from 2018). The methodology used for diagnosis is what is evolving most over the last years, with data set XXI (2019) showing around 7% of FISH, 37% of PCR and 55% of WGA. Within WGA 90.6% of the analysis were done using NGS, in 4.4% cases SNP arrays were used and in 2.4% array-CGH was used. The overall clinical pregnancy rate is about 24% per analysis. The baby data show that it is difficult for most centres to have a detailed follow-up.

Limitations, reasons for caution

The findings apply to the 31 participating centres and may not represent worldwide trends in PGT. Data were collected prospectively, but details of the follow-up on PGT pregnancies and babies born were limited.

Wider implications of the findings

The ESHRE PGD Consortium continues its activities as an important forum for PGT practitioners to share data and exchange experiences. The information extracted from the data collections helps to monitor quality issues in PGT and survey the introduction and effectiveness of new PGT technologies and methods.

P-536 Pre-selected for an award: Validation of a Next Generation Sequencing (NGS) workflow integrating simultaneous analysis of ploidy, microdeletions and de novo monogenic diseases for expanded preimplantation genetic testing (PGT)

Study question

Can major de novo genetic and chromosomal abnormalities (i.e., ploidy, microdeletions) be effectively tested on a single embryo biopsy specimen using an integrated NGS approach?

Summary answer

The integrated NGS workflow provided high accuracy for multilevel chromosome and genetic abnormalities analysis based on single biopsies expanding PGT informativity to de novo conditions.

What is known already

Current NGS-based methodologies employed in PGT for aneuploidy (PGT-A) do not detect embryo ploidy level nor frequent pathogenic de novo microdeletions below resolution limits. Moreover, despite their considerable incidence and adverse pregnancy outcomes, de novo mutations causing severe dominant monogenic fetal structural defects (FSD) are not investigated during PGT. The development of a single biopsy specimen-based PGT-A sequencing strategy that integrates ploidy and de novo microdeletions/mutations assessment would significantly widen PGT-A diagnostic scope and technical capabilities. This comprehensive approach would provide additional valuable genetic information of unquestionable clinical utility to further refine embryo selection process among those showing euploid profiles.

Study design, size, duration

Chromosomal conditions were validated using 24 embryo rebiopsies and 5 cell lines with both known ploidy level and known microdeletions (-4p; -8q; -1p; -22q; -5p; -15q; -11q). Genotyping for monogenic conditions was validated using 5 genomic DNA samples (33pg/µl) carrying known pathogenic Single Nucleotide Variants (SNVs) in COL1A1, SOS1, PTPN11, TSC2 and FGFR2 genes. To assess technical performance across identified SNPs, genotyping accuracy was evaluated on 17 samples from 5 embryos and 2 cell lines.

Participants/materials, setting, methods

Thirty-two de novo dominant monogenic conditions with FSD and strong gene-disease relationship were tested using a multiplex PCR panel with sequencing for the genes’ whole coding region. Eight common microdeletions ( &lt; 10Mb) syndromes (Wolf-Hirshorn, Langer-Geidion, 1p36 deletion, De George, Cri-du-Chat, Prader-Willy/Angelman, Jacobsen) were tested using B-allelic frequency (BAF) of 356 highly polymorphic Single Nucleotide Polymorphisms (SNPs). These SNPs were also used for ploidy assessment. Library preparation and sequencing were performed on the IonTorrent S5 (ThermoFisher).

Main results and the role of chance

Blinded NGS data analysis confirmed the ploidy status in all (19) samples with known constitution (8 diploids, 7 polyploids, 4 haploids). Specifically, the proportion of heterozygote calls (BAF 40%-60%) was 60.9% (95%CI:47.6-72.8) for diploid samples and &lt; 1% for haploid samples(P &lt; 0.001). All polyploid samples showed a typical splitting of BAF among 3 experimental ranges (20-40%,40%-60%,60-80%): 34.1%,18.2% and 47.7%, respectively. For microdeletions, all interstitial SNPs genotyped showed a loss of heterozygosity (LOH) as expected. The analysis of positive controls consisting of 20 blastocyst rebiopsies and 3 cell lines (-4p: n = 3; -8q: n = 4; -1p: n = 5; -22q: n = 3; -5p: n = 2; -15q: n = 4; -11q: n = 2), allowed to accurately characterize 6 out of the 7 microdeletions (18/23 samples). In particular, all interstitial SNPs genotyped showed a LOH, while diploid controls showed an overall heterozygosity of 30.9% (average number of hetSNP x deletion = 9/28). Only the very small telomeric 1p36 region failed to properly amplify. For monogenic conditions, sequencing analysis of 5 positive gDNA controls confirmed the presence of 4 known SNVs, whilst only 1 did not achieve the minimum coverage for variant calling. Moreover, 4 additional de novo SNVs detected by sequencing analysis in the gene panel on 8 blastocyst rebiopsies were all confirmed by qPCR/Taqman assays.

Limitations, reasons for caution

Positive controls were not available for all genes and microdeletions included in the panel. Moreover, inefficient amplification has affected some target regions and further optimization will be required. However, analytical performance on technical and biological replicates were highly promising for the tested conditions both cell lines and trophectoderm biopsies.

Wider implications of the findings

This study demonstrates that the integration of genotyping and chromosomal analyses can be efficiently achieved in the same NGS workflow. This approach can be employed to expand PGT diagnostic scope to conditions undetectable in parents due to their de novo onset, or that are below the standard PGT-A resolution.

Trial registration number

N/A

Valenciano JA, Jimene. Almazan J, Baù D, Rubio C, Bles. Jarque D, Simòn C, Capalbo A. P–536 Validation of a Next Generation Sequencing (NGS) workflow integrating simultaneous analysis of ploidy, microdeletions and de novo monogenic diseases for expanded preimplantation genetic testing (PGT)

Study question

Can major de novo genetic and chromosomal abnormalities (i.e., ploidy, microdeletions) be effectively tested on a single embryo biopsy specimen using an integrated NGS approach?

Summary answer

The integrated NGS workflow provided high accuracy for multilevel chromosome and genetic abnormalities analysis based on single biopsies expanding PGT informativity to de novo conditions.

What is known already

Current NGS-based methodologies employed in PGT for aneuploidy (PGT-A) do not detect embryo ploidy level nor frequent pathogenic de novo microdeletions below resolution limits. Moreover, despite their considerable incidence and adverse pregnancy outcomes, de novo mutations causing severe dominant monogenic fetal structural defects (FSD) are not investigated during PGT. The development of a single biopsy specimen-based PGT-A sequencing strategy that integrates ploidy and de novo microdeletions/mutations assessment would significantly widen PGT-A diagnostic scope and technical capabilities. This comprehensive approach would provide additional valuable genetic information of unquestionable clinical utility to further refine embryo selection process among those showing euploid profiles.

Study design, size, duration

Chromosomal conditions were validated using 24 embryo rebiopsies and 5 cell lines with both known ploidy level and known microdeletions (–4p; –8q; –1p; –22q; –5p; –15q; –11q). Genotyping for monogenic conditions was validated using 5 genomic DNA samples (33pg/µl) carrying known pathogenic Single Nucleotide Variants (SNVs) in COL1A1, SOS1, PTPN11, TSC2 and FGFR2 genes. To assess technical performance across identified SNPs, genotyping accuracy was evaluated on 17 samples from 5 embryos and 2 cell lines.

Participants/materials, setting, methods

Thirty-two de novo dominant monogenic conditions with FSD and strong gene-disease relationship were tested using a multiplex PCR panel with sequencing for the genes’ whole coding region. Eight common microdeletions (&lt;10Mb) syndromes (Wolf-Hirshorn, Langer-Geidion, 1p36 deletion, De George, Cri-du-Chat, Prader-Willy/Angelman, Jacobsen) were tested using B-allelic frequency (BAF) of 356 highly polymorphic Single Nucleotide Polymorphisms (SNPs). These SNPs were also used for ploidy assessment. Library preparation and sequencing were performed on the IonTorrent S5 (ThermoFisher).

Main results and the role of chance

Blinded NGS data analysis confirmed the ploidy status in all (19) samples with known constitution (8 diploids, 7 polyploids, 4 haploids). Specifically, the proportion of heterozygote calls (BAF 40%–60%) was 60.9% (95%CI:47.6–72.8) for diploid samples and &lt;1% for haploid samples(P &lt; 0.001). All polyploid samples showed a typical splitting of BAF among 3 experimental ranges (20–40%,40%–60%,60–80%): 34.1%,18.2% and 47.7%, respectively. For microdeletions, all interstitial SNPs genotyped showed a loss of heterozygosity (LOH) as expected. The analysis of positive controls consisting of 20 blastocyst rebiopsies and 3 cell lines (–4p: n = 3; –8q: n = 4; –1p: n = 5; –22q: n = 3; –5p: n = 2; –15q: n = 4; –11q: n = 2), allowed to accurately characterize 6 out of the 7 microdeletions (18/23 samples). In particular, all interstitial SNPs genotyped showed a LOH, while diploid controls showed an overall heterozygosity of 30.9% (average number of hetSNP x deletion=9/28). Only the very small telomeric 1p36 region failed to properly amplify. For monogenic conditions, sequencing analysis of 5 positive gDNA controls confirmed the presence of 4 known SNVs, whilst only 1 did not achieve the minimum coverage for variant calling. Moreover, 4 additional de novo SNVs detected by sequencing analysis in the gene panel on 8 blastocyst rebiopsies were all confirmed by qPCR/Taqman assays.

Limitations, reasons for caution

Positive controls were not available for all genes and microdeletions included in the panel. Moreover, inefficient amplification has affected some target regions and further optimization will be required. However, analytical performance on technical and biological replicates were highly promising for the tested conditions both cell lines and trophectoderm biopsies.

Wider implications of the findings: This study demonstrates that the integration of genotyping and chromosomal analyses can be efficiently achieved in the same NGS workflow. This approach can be employed to expand PGT diagnostic scope to conditions undetectable in parents due to their de novo onset, or that are below the standard PGT-A resolution.

Trial registration number

N/A

O-237 A non-invasive approach for aneuploidy analysis in clinical miscarriages

Study question

Is maternal cell-free DNA (cfDNA) testing a feasible alternative to the analysis of the product of conception (POC) in clinical miscarriages?

Summary answer

This study demonstrates that genome-wide cfDNA testing in the maternal bloodstream constitutes a reliable tool to analyse chromosome aneuploidies in clinical miscarriages.

What is known already

It is well established that 50-70% of clinical miscarriages are caused by numerical chromosomal anomalies (aneuploidies), mostly trisomies. To date, conventional cytogenetic and advanced molecular techniques are used for the analysis of POC to identify the genetic cause of miscarriage, providing valuable information for genetic counselling. However, both approaches are based in the direct analysis of the abortive tissue, which entails several limitations due to the risk of culture failure and/or maternal cell contamination. To solve these drawbacks, maternal cfDNA testing emerges as a promising alternative due to the accumulated evidence.

Study design, size, duration

This was a retrospective study conducted in a reference genetic laboratory from January to December 2020. Before carrying out the foetal tissues collection that precludes the POC analysis, a blood sample was drawn to evaluate possible aneuploidies by cfDNA testing. Using NGS+STR POC results as the gold standard, results derived from both studies were compared to assess the percentage of concordance and the cases of non-informativeness (foetal fraction (FF) &lt;2%), false positives, and false negatives.

Participants/materials, setting, methods

A total of 12 cases were included in the study. cfDNA testing in the mother’s blood was performed by using Illumina’s technology platform. Genetic testing for POC was done using an NGS technology (Thermo Fisher Scientific, USA) for 24 chromosome aneuploidy screening. Short-tandem repeat (STR) analysis allowed us to detect or rule out maternal cell contamination (MCC) and some types of polyploidies.

Main results and the role of chance

The non-informative rate for both analysis techniques was 9.1% (1 out of 12 cases: 1 low FF for cfDNA testing and maternal cell contamination for POC analysis). The median cfDNA FF was 9.0%. Using the molecular POC analysis as gold standard, the concordance rate between both studies was 90.0% (9 out of 10 cases;1 monosomy X, 1 trisomy (T) 21, 1 T22, 1 T11 and 5 patients with no alteration detected). No mosaics or structural rearrangements were identified by either of the two analysis techniques. The only discordant result was a case in which cytogenetics of POCs identified a triploidy. This discordancy is expected since triploidies are outside the scope of cfDNA testing. Also, foetal sex was correctly assigned in all informative cases. The sensibility and specificity of the study were estimated at 80.0 (4/5) and 100.0% (6/6), respectively. Statistics analysis suggested that no significant difference was found between both techniques regarding the aneuploidy detection ability (P=0.5). These promising results indicate that genome-wide cfDNA-based screening provides a non-invasive approach for determining whether foetal aneuploidy could explain the loss in patients experiencing early o recurrent pregnancy loss (RPL).

Limitations, reasons for caution

The sample size prevents drawing more significant conclusions regarding the diagnosis power similarity between both testing techniques. Therefore, a larger cohort will be essential to improve confirm the cfDNA testing performance. Current cfDNA testing technology fails in polyploidy identification, which is a potential cause of pregnancy loss.

Wider implications of the findings

CfDNA testing could be an alternative to POC analysis in clinical miscarriage. If optimized, cfDNA testing could be used contingently with the molecular POC analysis in cases where maternal cell contamination is present. As a result, the overall success rate in the POC program could be substantially improved.

Trial registration number

NA

Zamora R, Gome. Rodríguez J, Paz S, Hardisso. d. l. Torre A, Gutierrez A, Rubio C, Hess-Medler S. P–059 Association between seminal levels of Fe and semen quality

Study question

The detection of metals in semen offers a new field in the study of male infertility.

Summary answer

Normozoospermia is associated with higher amounts of Fe. In males with pathological spermiogram, the percentage of men with Fe in semen was lower than expected.

What is known already

Increased levels of Fe in human semen appear to have a significant correlation with male fertility, suggesting that Fe in human seminal plasma has an important factor in male reproductive function. Fe acts as an antioxidant being a co-factor of catalasa, which protects sperm. On the other hand, elevated Fe levels are associated with sperm damage and continues to increase the lipid peroxidation that will affect the plasma membrane and the sperm motility. Most authors associate Fe with sperm motility and higher estimated fertility potential, based on standard semen parameters in fertile men, which are associated with lower levels of Fe.

Study design, size, duration

A prospective study was carried out in 102 men in a Reproduction unit in Tenerife, from February to April 2018 as a part on an epidemiologic study of environmental contaminants and male reproduction. The participant were categorized into two groups, according to the results of semen analysis following the World Health Organization guidelines: the pathological and the normal semen group that constituted the control group. The metal was determined in semen samples.

Participants/materials, setting, methods

Semen quality and levels of Fe were measured in seminal plasma on a total of 102 men attended successively, for the initial infertility evaluation, The collected samples were used for both semen analysis following the World Health Organization (WHO) guidelines and metal detection and carried out using a Makler® counting chamber (Irvine Scientific, CA) and for metals, were determined by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) in semen samples.

Main results and the role of chance

The percentage of males with the presence of Fe was 97.1% and the average level were 0.6283 mg/Kg. When analyzing the relationship between the spermiogram parameters with the levels of Fe in the semen, significant differences were found. All men with a normal sperm analysis presented Fe in semen, but among men diagnosed with altered spermiogram, the percentage of men with Fe in semen (92.7%) was lower than expected (97%) (χ2 128 1 =4.59; p = 0.032). As for the concentration of Fe in spermiogram in the first quartile (25% lower), measuring 0.33 mg/Kg, more pathological samples were found than expected (X2 133 2 =6.921; p = 0.031) having a higher probability of being more pathological (52% vs 31.4%). On the other hand, men with pathological sperm concentration, have higher levels of Fe, in the fourth quartile (0.61 mg/kg), with more frequency than expected (90.6% vs 97%) (χ2 136 1 =6.48; p = 0.011). The association between BMI and the presence of Fe was statistically significant. In obese males (BMI ≥30.0 kg/m2), the percentage of men with Fe in semen (80%) was lower than expected (97%) (χ2 42 2 =11.302; p = 0.001).

Limitations, reasons for caution

The limitation of this study was the volume of semen that could be obtained for metal detection, only 0.8 mL. because the collected samples were used for both semen analysis and metal detection.

Wider implications of the findings: The determination of metals in semen opens a new field in the study of male infertility and many cases of unknown infertility could be due to metal presence or absence in semen, with the option of performing treatments.

Trial registration number

Not applicable