What does "Advanced" mean in 2023? reflecting on 10 years of the ESTRO advanced Skills in modern radiotherapy course.

The roles and responsibilities of radiation therapists (RTTs) are many and varied. Professional expectations are influenced by the technology available, as well as the level of autonomy RTTs have in their daily practice. This professional range requires RTTs to possess a unique set of ever evolving skills, posing challenges from an educational perspective. Teaching these "advanced skills" has been the ambition the ESTRO Advanced Skills in Modern Radiotherapy course. In the 10th year of this course, the Faculty look back and reflect on how our programme has evolved and what it has achieved.

ESTRO clinical practice guideline: Stereotactic body radiotherapy for spine metastases.

BACKGROUND AND PURPOSE: Recent progress in diagnostics and treatment of metastatic cancer patients have improved survival substantially. These developments also affect local therapies, with treatment aims shifting from short-term palliation to long-term symptom or disease control. There is consequently a need to better define the value of stereotactic body radiotherapy (SBRT) for the treatment of spinal metastases. METHODS: This ESTRO clinical practice guideline is based on a systematic literature review conducted according to PRISMA standards, which formed the basis for answering four key questions about the indication and practice of SBRT for spine metastases. RESULTS: The analysis of the key questions based on current evidence yielded 22 recommendations and 5 statements with varying levels of endorsement, all achieving a consensus among experts of at least 75%. In the majority, the level of evidence supporting the recommendations and statements was moderate or expert opinion, only, indicating that spine SBRT is still an evolving field of clinical research. Recommendations were established concerning the selection of appropriate patients with painful spine metastases and oligometastatic disease. Recommendations about the practice of spinal SBRT covered technical planning aspects including dose and fractionation, patient positioning, immobilization and image-guided SBRT delivery. Finally, recommendations were developed regarding quality assurance protocols, including description of potential SBRT-related toxicity and risk mitigation strategies. CONCLUSIONS: This ESTRO clinical practice guideline provides evidence-based recommendations and statements regarding the selection of patients with spinal metastases for SBRT and its safe implementation and practice. Enrollment of patients into well-designed prospective clinical trials addressing clinically relevant questions is considered important.

Efficacy and safety of SBRT for spine metastases: A systematic review and meta-analysis for preparation of an ESTRO practice guideline.

BACKGROUND AND PURPOSE: Advances in characterizing cancer biology and the growing availability of novel targeted agents and immune therapeutics have significantly changed the prognosis of many patients with metastatic disease. Palliative radiotherapy needs to adapt to these developments. In this study, we summarize the available evidence for stereotactic body radiotherapy (SBRT) in the treatment of spinal metastases. MATERIALS AND METHODS: A systematic review and meta-analysis was performed using PRISMA methodology, including publications from January 2005 to September 2021, with the exception of the randomized phase III trial RTOG-0631 which was added in April 2023. Re-irradiation was excluded. For meta-analysis, a random-effects model was used to pool the data. Heterogeneity was assessed with the I2-test, assuming substantial and considerable as I2 > 50 % and I2 > 75 %, respectively. A p-value < 0.05 was considered statistically significant. RESULTS: A total of 69 studies assessing the outcomes of 7236 metastases in 5736 patients were analyzed. SBRT for spine metastases showed high efficacy, with a pooled overall pain response rate of 83 % (95 % confidence interval [CI] 68 %-94 %), pooled complete pain response of 36 % (95 % CI: 20 %-53 %), and 1-year local control rate of 94 % (95 % CI: 86 %-99 %), although with high levels of heterogeneity among studies (I2 = 93 %, I2 = 86 %, and 86 %, respectively). Furthermore, SBRT was safe, with a pooled vertebral fracture rate of 9 % (95 % CI: 4 %-16 %), pooled radiation induced myelopathy rate of 0 % (95 % CI 0-2 %), and pooled pain flare rate of 6 % (95 % CI: 3 %-17 %), although with mixed levels of heterogeneity among the studies (I2 = 92 %, I2 = 0 %, and 95 %, respectively). Only 1.7 % of vertebral fractures required surgical stabilization. CONCLUSION: Spine SBRT is characterized by a favorable efficacy and safety profile, providing durable results for pain control and disease control, which is particularly relevant for oligometastatic patients.

Thorough design and pre-trial quality assurance (QA) decrease dosimetric impact of delineation and dose planning variability in the STRICTLUNG and STARLUNG trials for stereotactic body radiotherapy (SBRT) of central and ultra-central lung tumours.

INTRODUCTION: SBRT of central lung tumours implies significant risk of toxicity. We are initiating two phase II trials prescribing 56 Gy/eight fractions to PTV, allowing for dose escalation of GTV. We prioritize organs at risk (OAR) constraints over target coverage, making the treatment plans very sensitive to OAR delineation variations. The aim of this study is to quantify the dosimetric impact of contouring variations and to provide a thorough description of pre-trial quality assurance to be used in upcoming trials to provide consistent clinical care. MATERIALS AND METHODS: Delineation: Seven physicians delineated OAR in three rounds, with evaluations in-between. For each patient case, seven treatment plans, repeatedly using each of the OAR structure sets from the seven physicians, were made and compared to evaluate the dosimetric effect of delineation variability. Treatment planning: Treatment plans for seven cases were made at six departments in two rounds, with discussion in-between. RESULTS: OAR delineation variation between centres resulted in high variabilities in OAR dose for simulated plans and led to potential overdosage of the lobar bronchus (constraint: D0.03cc < 45 Gy), with maximum doses ranging between 58 Gy (first round), and 50 Gy (third round). For mediastinal tissue, the constraint (D0.03cc < 45 Gy) was violated for the majority of the delineations in all three rounds, with maximum doses of 84 Gy (first round), and 72 Gy (third round).For the treatment planning study, the range of the standard deviation for GTV mean dose was 12.8-18.5 Gy (first round) and 2.8-3.5 Gy (second round). CONCLUSIONS: Even small variations in OAR delineation led to high OAR overdosage. The study demonstrates the importance of having extensive QA procedures in place before initiating clinical trials on dose escalation in SBRT.

Effects of isoflurane anesthesia and pilocarpine on rat parotid saliva flow.

The purpose of this study was to investigate the effects of isoflurane on unstimulated and pilocarpine-stimulated parotid saliva secretion. Ten male Sprague-Dawley rats weighing 350-400 g were randomized into two groups, and the saliva flow rate and lag phase were measured at two doses of isoflurane in a crossover study design. Increasing the isoflurane concentration from 1% to 2% was associated with a 19% decrease in saliva secretion rate, and the lag to saliva secretion was increased by 155%. To clarify whether the effect of isoflurane (1.5%) on the parotid flow varied with stimulus intensity, we measured the parotid flow induced by seven different doses of pilocarpine on sham-irradiated rats and rats irradiated with single doses of 15 Gy. A maximal pilocarpine response was obtained with 1.5 mg/kg in both irradiated and sham-irradiated rats; however, the parotid flow of the irradiated rats was 50% slower than that of the sham-irradiated rats. In conclusion, 1.5% isoflurane was found to be a good compromise between proper anesthesia and isoflurane-induced inhibition of saliva secretion. Pilocarpine induces saliva secretion in a dose-dependent matter, with supra-maximal stimulation achieved using 1.5 mg/kg.

Evaluation of dose to cardiac structures during breast irradiation.

OBJECTIVE: Adjuvant radiotherapy for breast cancer can lead to late cardiac complications. The highest radiation doses are likely to be to the anterior portion of the heart, including the left anterior descending coronary artery (LAD). The purpose of this work was to assess the radiation doses delivered to the heart and the LAD in respiration-adapted radiotherapy of patients with left-sided breast cancer. METHODS: 24 patients referred for adjuvant radiotherapy after breast-conserving surgery for left-sided lymph node positive breast cancer were evaluated. The whole heart, the arch of the LAD and the whole LAD were contoured. The radiation doses to all three cardiac structures were evaluated. RESULTS: For 13 patients, the plans were acceptable based on the criteria set for all 3 contours. For seven patients, the volume of heart irradiated was well below the set clinical threshold whereas a high dose was still being delivered to the LAD. In 1 case, the dose to the LAD was low while 19% of the contoured heart volume received over 20 Gy. In five patients, the dose to the arch LAD was relatively low while the dose to the whole LAD was considerably higher. CONCLUSION: This study indicates that it is necessary to assess the dose delivered to the whole heart as well as to the whole LAD when investigating the acceptability of a breast irradiation treatment. Assessing the dose to only one of these structures could lead to excessive heart irradiation and thereby increased risk of cardiac complications for breast cancer radiotherapy patients.