1.5T MR-Guided Daily Adaptive Radiotherapy: Preliminary Clinical Report of the First 5000 Fractions

PURPOSE/OBJECTIVE(S)

1.5T MR-Linac improves target volume and adjacent OARs visualization, ensuring high precision in radiation treatment delivery. Daily MR-imaging allows on-table adapted planning and real-time intra-fraction imaging without additional exposure to radiation. Our department implemented the first high field MRgRT system in Italy and herein we present the preliminary report of the first 5000 fractions delivered. We aim to describe the clinical implementation, feasibility, toxicity and patient tolerability of daily adapted RT.

MATERIALS/METHODS

Since October 2019, 1.5T MR-Linac has been available in our department. A prospective observational study for the clinical use of 1.5T MR-Linac is currently ongoing in our department: patients affected by prostate adenocarcinoma, pancreatic cancer, oligometastases and patients requiring retreatments were included. Two different workflows were used depending on the OARs daily anatomy: Adapt To Position (ATP) where the reference plan position is adjusted rigidly to match the position of the targets and OARs, and Adapt To Shape (ATS) where a new plan is created to better match the anatomy of the day. Toxicity and quality of life were assessed at baseline and after treatment using the CTCAE v5.0. Patient-reported outcomes of prostate cancer patients were investigated by means IPSS, ICIQ-SF, IIEF-5, EPIC-26, EORTC-QLQ-C30 and PR-25 questionnaires.

RESULTS

Between October 2019 and June 2022, 590 patients with 675 target sites were treated with MR-guided radiation therapy in 5000 total fractions. Median patient age was 70 years (39-86). Among 675 tumor sites, the most frequently treated region was pelvis (n = 549, 81%). The most common diagnosis was prostate cancer (n = 326). On-table adaptive radiation therapy was used at every treatment session: ATP workflow in 63 fractions (1%) and ATS workflow in 4937 fractions (99%), respectively. Median prescribed dose was 35 Gy (20-67.5 Gy) in median 5 fractions (5-30). Mean total treatment time was 43 minutes (20-56). Treatments were well-tolerated and no acute G>3 toxicities were reported. Concerning the PROMS, all questionnaires showed no relevant deterioration between the pre-, post-RT and follow-up evaluations.

CONCLUSION

MR-guided radiation treatment using 1.5T MR-Linac has been successfully implemented into clinical routine at our department. The data reported support an optimal profile of tolerability of daily on-table adaptive radiation therapy in acceptable time slots. These results are confirmed by PROMs.

A multicenter LArge retrospectIve daTabase on the personalization of Stereotactic ABlative Radiotherapy use in lung metastases from colon-rectal cancer: the LaIT-SABR study

INTRODUCTION

stereotactic ablative radiotherapy (SABR) has been shown to increase survival in oligometastatic disease, but local control of colorectal metastases remains poor. We aimed to identify potential predictive factors of SBRT response through a multicenter large retrospective database and to investigate the progression to the polymetastatic disease (PMD).

MATERIAL AND METHODS

the study involved 23 centers, and was approved by the Ethical Committee (Prot. Negrar 2019-ZT). 1033 lung metastases were reported. Clinical and biological parameters were evaluated as predictive for local progression-free survival (FLP). Secondary end-point was the time to the polymetastatic conversion (tPMC).

RESULTS

Two-year FLP was 75.4%. Two-year FLP for lesions treated with a BED <100 Gy, 100-124 Gy, and ≥125 Gy was 76.1%, 70.6%, and 94% (p=0.000). Two-year FLP for lesion measuring ≤10 mm, 10-20 mm, and >20 mm was 79.7%, 77.1%, and 66.6% (p=0.027). At the multivariate analysis a BED ≥125 Gy significantly reduced the risk of local progression (HR 0.24, 95%CI 0.11-0.51; p=0.000). Median tPMC was 26.8 months. Lesions treated with BED ≥125 Gy reported a significantly longer tPMC as compared to lower BED. The median tPMC for patients treated to 1, 2-3 or 4-5 simultaneous oligometastases was 28.5, 25.4, and 9.8 months (p=0.035).

CONCLUSION

The present is the largest series of lung colorectal metastases treated with SABR. The results support the use of SBRT in lung oligometastatic colorectal cancer patients as it might delay the transition to PMD or offer relatively long disease-free period in selected cases. Predictive factors were identified for treatment personalization.

Long-term disease outcome and volume-based decision strategy in a large cohort of multiple brain metastases treated with a mono-isocentric linac-based Stereotactic Radiosurgery technique

PURPOSE

Radiosurgery (SRS) is an effective treatment option for brain metastases (BMs). Long-term results of the first worldwide experience with a mono-isocentric, non-coplanar, linac-based stereotactic technique in the treatment of multiple BMs are reported.

METHODS

patients with multiple BMs, life expectancy > 3 months, and good performance status (≤ 2) were treated with simultaneous SRS with volumetric modulated arc technique. Data were retrospectively evaluated.

RESULTS

172 patients accounting for 1079 BMs were treated at our institution from 2017 to 2020. The median number of treated metastases was 4 (range 2-22). Primary tumor histology was: lung (44.8%), breast (32%), and melanoma (9.4%). The 2-year LPFS was 71.6%, respectively. A biological effective dose (BED) ≥ 51.3 Gy₁₀ correlated with higher local control. Uncontrolled systemic disease and melanoma histology were independent prognostic factors correlated with decreased iPFS. Patients with > 10 BMs had a trend towards shorter iPFS (p = 0.055). 31 patients received multiple SRS courses (2-7) in case of intracranial progression. The median iOS was 22.4 months. Brainstem metastases and total PTV > 7.1 cc correlated with shorter iOS. The 1- and 2-year WBRT-free survival was 83.2% and 61.1%, respectively.

CONCLUSION

Long-term results in a large patient population treated with a mono-isocentric, dedicated technique demonstrated its effectiveness and safety also in the case of multiple courses. The shortened treatment time and the possibility to safely spare healthy brain tissue allows the safe treatment of patients with a large number of metastases and to deliver multiple courses of SRS. In selected cases, the administration of WBRT can be delayed.

Diabetic retinopathy in well-controlled type 2 diabetes: Role of glycaemic memory

AIMS

As diabetic retinopathy (DR) can occur even in well-controlled patients with type 2 diabetes (T2D), our study sought to determine whether it might be related to 'glucose memory' by evaluating patients' HbA1c over previous years and their skin autofluorescence (SAF).

METHODS

In 334 patients with T2D and HbA1c levels≤8%, their available values of HbA1c from previous years were collected, and their SAF measured by an advanced glycation end-product (AGE) reader. Binary logistic regression analysis was then used to correlate DR with previously recorded HbA1c levels and to SAF, with adjustment for DR risk factors [age, gender, BMI, duration of diabetes, arterial hypertension, diabetic kidney disease (DKD), blood lipid levels and statin treatment].

RESULTS

Our patients were mostly men (58.4%) aged 63±10years, with a duration of diabetes of 13±10years and HbA1c=7.1±0.7%. Of these patients, 84 (25.1%) had DR, which was associated with longer duration of diabetes and greater prevalence of DKD. A total of 605 HbA1c values from previous years were collected for time periods -4±3 months (n=255), -16±4months (n=152), -30±4months (n=93) and -62±26 months (n=105). After adjustment, the association between DR and having an HbA1c higher than the median was significant only for the oldest previous HbA1c values: OR=6.75, 95% CI: 1.90-23.90. Moreover, SAF values were higher in those with DR [2.95±0.67 arbitrary units (AU)] vs 2.65±0.65 AU with no DR (P<0.01) and were also associated with the oldest previous HbA1c values (P<0.01).

CONCLUSION

Our study found that 25.1% of our well-controlled T2D patients had DR, which was related to both their HbA1c levels from 5years prior to study admission and their SAF values, a marker of glucose memory.

2,4,6-Triphenylphosphinine and 2,4,6-triphenylposphabarrelene revisited: synthesis, reactivity and coordination chemistry

Important aspects of the synthesis, reactivity and coordination chemistry of 2,4,6-triphenylphosphinine and 2,4,6-triphenylphosphabarrelene have been revisited.

Bracing for scoliosis in 2014: state of the art

Bracing is currently the primary method for treating moderate idiopathic scoliosis (IS) during the developmental phase of growth. Following a lengthy debate, during which researchers and authors questioned the role of bracing in the treatment of IS due to inconsistent evidence, the Bracing in Adolescent Idiopathic Scoliosis Trial study have provided a high level of evidence to the value of bracing and may have convinced most of those who were skeptic. However, although some guidelines have been published, there remains no standard for constructing scoliosis orthoses and no standard treatment protocol. The Scoliosis Research Society criteria were established to provide a framework by which to research bracing and adolescent idiopathic scoliosis, and the Society on Scoliosis Orthopedic and Rehabilitation Treatment criteria were published to guarantee a minimum level of expertise for MDs and CPOs involved in the brace treatment. However, very few contemporary papers follow both sets of criteria, and the extensive variety of braces makes it difficult to determine if one is superior to another. The aim of this paper is to provide an overview of state-of-the-art brace treatment, highlighting commonly used braces and their history, biomechanical concept, and results, as reported in published literature. Specific focus is placed on European (i.e., Chêneau and derivatives, Dynamic Derotating, Lyon, PASB, Sforzesco, TLI, TriaC) and North American (i.e. Boston, Charleston, Milwaukee, Providence, Rosenberger, SpineCor, Wilmington) designs. Details about different building techniques are also reported, along with recently developed tools that are designed to monitor compliance.

Actual evidence in the medical approach to adolescents with idiopathic scoliosis

Idiopathic scoliosis (IS) is a three-dimensional deformity of the spine and trunk. The most common form involve adolescents. The prevalence is 2-3% of the population, with 1 out of 6 patients requiring treatment of which 25% progress to surgery. Physical and rehabilitation medicine (PRM) plays a primary role in the so-called conservative treatment of adolescents with IS, since all the therapeutic tools used (exercises and braces) fall into the PRM domain. According to a Cochrane systematic review there is evidence in favor of bracing, even if it is of low quality. Recently, a controlled prospective trial including a randomised arm gave more strength to this conclusion. Another Cochrane review shows that there is evidence in favor of exercises as an adjunctive treatment, but of low quality. Three meta-analysis have been published on bracing: one shows that bracing does not reduce surgery rates, but studies with bracing plus exercises were not included and had the highest effectiveness; another shows that full time is better than part-time bracing; the last focuses on observational studies following the Scoliosis Research Society (SRS) criteria and shows that not all full time rigid bracing are the same: some have the highest effectiveness, others have less than elastic and nighttime bracing. Two very important RCTs failed in recruitment, showing that in the field of bracing for scoliosis RCTs are not accepted by the patients. Consensuses by the international Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT) show that there is no agreement among experts either on the best braces or on their biomechanical action, and that compliance is a matter of clinical more than patients' behavior (there is strong agreement on the management criteria to achieve best results with bracing). A systematic review of all the existing studies shows effectiveness of exercises, and that auto-correction is their main goal. A systematic review shows that there are no studies on manual treatment. The SOSORT Guidelines offer the actual standard of conservative care.