Survivorship program including long-term toxicities and quality-of-life development over 10 years in a randomized trial in operable stage III non-small-cell lung cancer (ESPATUE).

Over 40% stage-III non-small-cell lung cancer (NSCLC) patients (pts) experience 5-year survival following multimodality treatment. Nevertheless, little is known about relevant late toxicities and quality-of-life (QoL) in the further long-term follow-up. Therefore, we invited pts from our randomized phase-III trial (Eberhardt et al., Journal of Clinical Oncology 2015) after 10 years from diagnosis to participate within a structured survivorship program (SSP) including follow-up imaging, laboratory parameters, cardio-pulmonary investigations, long-term toxicity evaluations and QoL questionnaires. Of 246 pts initially accrued, 161 were considered potentially resectable following the induction therapy and were randomized (80 to arm A: definitive chemoradiation; 81 to arm B: definitive surgery; 85 not randomized for different reasons; group C). 31 from 37 pts still alive after 10 years agreed to the SSP (13 in A; 12 in B; 6 in C). Clinically relevant long-term toxicities (grade 3 and 4) were rarely observed with no signal favoring any of the randomization arms. Furthermore, available data from the global QoL analysis did not show a signal favoring any definitive locoregional approach (Mean QoL in SSP A pts: 56.41/100, B pts: 64.39/100) and no late decline in comparison to baseline and early 1-year follow-up. This is the first comprehensive SSP of very late survival follow-up reported in stage-III NSCLC treated within a randomized multimodality trial and it may serve as important baseline information for physicians and pts deciding for a locoregional treatment option.

Tumor- and Radiation-Related Complications after Ruthenium-106 Brachytherapy in Small to Medium Uveal Melanomas (Part 1).

PURPOSE: The purpose of this study was to analyze tumor-related complications after ruthenium-106 brachytherapy in patients with uveal melanoma, with respect to local tumor control, insufficient radiation response, enucleation, and metastasis rate. PATIENTS/METHODS AND MATERIALS: This retrospective study included 608 patients treated consecutively with ruthenium-106 brachytherapy between January 2008 and December 2010 at the Department of Ophthalmology, University Hospital Essen. The occurrence of radiation-induced results was analyzed by estimating the risk by applying the Kaplan-Meier method, i.e., the "time to event" analysis. The Cox model test was used for the univariate and multivariate risk factor analyses. The median follow-up was 51 months after primary treatment. RESULTS: Tumor recurrence was found in 21 patients (3.5%) and repeated treatment due to insufficient effect after the initial ruthenium-106 brachytherapy was performed in 40 patients (6.6%). The 5-year cumulative risk of recurrence was 4.0% and that of insufficient effect was 7.3%. Thirteen patients (2.1%) underwent a secondary enucleation; 8 because of a local recurrence and 5 because of severe post-brachytherapy complications. The cumulative enucleation risk was 2.3% after 5 years and 2.9% after 10 years, corresponding to eye preservation of 97.7 and 97.1%, respectively. In forty-two patients (7.2%), metastatic disease was diagnosed during the follow-up. The metastatic rate as calculated by the Kaplan-Meier method was 9.0, and 13.1% at 5 and 10 years, respectively. CONCLUSION: Our study demonstrated that ruthenium-106 brachytherapy is an excellent treatment option for achieving local tumor control and eye preservation in well-selected patients. The metastatic rate is in agreement with that of previous studies analyzing small to medium size uveal melanomas.

Treatment-Related Complications and Functional Results after Ruthenium-106 Brachytherapy in Small to Medium Size Uveal Melanomas (Part 2).

PURPOSE: To analyze the treatment-related complications after ruthenium-106 brachytherapy in patients with uveal melanoma in terms of radiation-induced optic neuropathy, maculopathy and retinopathy, radiation-related vitreous hemorrhage, and retinal detachment, as well as secondary glaucoma and radiogenic cataract. In addition, the course of visual acuity was analyzed. PATIENTS/METHODS AND MATERIALS: This retrospective study included 608 patients treated with ruthenium-106 brachytherapy between January 2008 and December 2010 at the Department of Ophthalmology, University Hospital Essen. The follow-up time was 11 years. The occurrence of the radiation-induced complications was analyzed using the Kaplan-Meier method. Cox regression was used for univariate and multivariate risk factor analyses. Hazard ratios were calculated for each variable. RESULTS: Regarding the complications, 34% (N = 207) of the patients had no reported side effects or complications during follow-up. Radiation optic neuropathy was observed in 18.8% (N = 114) of the patients, with a median time to onset of 16 months (range: 3 - 78 months). Radiation maculopathy occurred in 8.2% (N = 50) after a median time of 17 months (range: 3 - 67 months). Radiation retinopathy was observed in 20.1% (N = 122), with a median time to onset of 21 months (range: 6 - 67 months). Secondary glaucoma developed in 9.7% of the patients (N = 53) and radiogenic cataract in 46.8% (N = 227). Vitreous hemorrhage (11.8%, N = 72) and scleral necrosis (2.1%, N = 13) occurred relatively rarely. CONCLUSION: The observed radiogenic complication rate is comparable with that reported in previous studies.

Usability and usefulness of (electronic) patient identification systems-A cross-sectional evaluation in German-speaking radiation oncology departments.

PURPOSE: Patient misidentification in radiation oncology (RO) is a significant concern due to the potential harm to patient health and the burden on healthcare systems. Electronic patient identification systems (ePIS) are increasingly being used as an alternative or supplement to organizational systems (oPIS). The objective of this study was to assess the usability and usefulness of ePIS and oPIS in German-speaking countries. METHODS: A cross-sectional survey was designed by a group of experts from various professional backgrounds in RO. The survey consisted of 38 questions encompassing quantitative and qualitative data on usability, user experience, and usefulness of PIS. It was available between August and October 2022. RESULTS: Of 118 eligible participants, 37% had implemented some kind of ePIS. Overall, 22% of participants who use an oPIS vs. 10% of participants who use an ePIS reported adverse events in terms of patients' misidentification in the past 5 years. Frequent or very frequent drop-outs of electronic systems were reported by 31% of ePIS users. Users of ePIS significantly more often affirmed a positive cost-benefit ratio of ePIS as well as an improvement of workflow, whereas users of oPIS more frequently apprehended a decrease in staffs' attention through ePIS. The response rate was 8%. CONCLUSION: The implementation of ePIS can contribute to efficient PI and improved processes. Apprehensions by oPIS users and assessments of ePIS users differ significantly in aspects of the perceived usefulness of ePIS. However, technical problems need to be addressed to ensure the reliability of ePIS. Further research is needed to assess the impact of different PIS on patient safety in RO.

Brachytherapy as a curative option for ocular surface squamous neoplasia.

PURPOSE: Ocular surface squamous neoplasia (OSSN) has a high recurrence rate if only treated with surgical excision, especially in cases with positive excision margins. To reduce recurrence, we used brachytherapy after surgical excision for limbal and bulbar lesions in addition to chemotherapy/immunotherapy, cryotherapy, or external beam radiotherapy as adjunctive or primary therapies. METHODS: Nine eyes with isolated OSSN lesions were included in the study. Adjunctive brachytherapy with Ruthenium106-plaques was administered. The follow-up included regular biomicroscopic slit-lamp examination and photo-documentation. Additionally, a staging check for metastasis was performed in cases with squamous cell carcinoma (SCC). RESULTS: The average age of patients at the time of presentation was 66 ± 12 years. Follow-up time was 52.8 ± 44.6 months. The maximal tumour base varied between 3 and 28 mm. SCC was confirmed by histology in all cases. No recurrences were recorded during the follow-up, and organ salvage and eye function preservation were achieved. Radiotherapy-induced complications included secondary glaucoma (n = 1) and scleral melting (n = 1). Other complications, such as radiogenic retinopathy, were not observed. CONCLUSION: Brachytherapy with Ruthenium106-plaques offers an additional option for adjunct treatment of limbal and bulbar OSSN presenting with only a focal spread. Organ salvage can be achieved with a low complication rate and recurrence-free survival. This technique offers globe salvage in patients with tumours involving intraocular infiltration.

Tumor DNA-methylome derived epigenetic fingerprint identifies HPV-negative head and neck patients at risk for locoregional recurrence after postoperative radiochemotherapy.

Biomarkers with relevance for loco-regional therapy are needed in human papillomavirus negative aka HPV(-) head and neck squamous cell carcinoma (HNSCC). Based on the premise that DNA methylation pattern is highly conserved, we sought to develop a reliable and robust methylome-based classifier identifying HPV(-) HNSCC patients at risk for loco-regional recurrence (LR) and all-event progression after postoperative radiochemotherapy (PORT-C). The training cohort consisted of HPV-DNA negative HNSCC patients (n = 128) homogeneously treated with PORT-C in frame of the German Cancer Consortium-Radiation Oncology Group (DKTK-ROG) multicenter biomarker trial. DNA Methylation analysis was performed using Illumina 450 K and 850 K-EPIC microarray technology. The performance of the classifier was integrated with a series of biomarkers studied in the training set namely hypoxia-, 5-microRNA (5-miR), stem-cell gene-expression signatures and immunohistochemistry (IHC)-based immunological characterization of tumors (CD3/CD8/PD-L1/PD1). Validation occurred in an independent cohort of HPV(-) HNSCC patients, pooled from two German centers (n = 125). We identified a 38-methylation probe-based HPV(-) Independent Classifier of disease Recurrence (HICR) with high prognostic value for LR, distant metastasis and overall survival (P < 10-9 ). HICR remained significant after multivariate analysis adjusting for anatomical site, lymph node extracapsular extension (ECE) and size (T-stage). HICR high-risk tumors were enriched for younger patients with hypoxic tumors (15-gene signature) and elevated 5-miR score. After adjustment for hypoxia and 5-miR covariates, HICR maintained predicting all endpoints. HICR provides a novel mean for assessing the risk of LR in HPV(-) HNSCC patients treated with PORT-C and opens a new opportunity for biomarker-assisted stratification and therapy adaptation in these patients.

Long-term follow-up and health-related quality of life among cancer survivors with stage IEA orbital-type lymphoma after external photon-beam radiotherapy: Results from a longitudinal study.

We assessed the long-term outcomes and treatment-related adverse effects of patients with Stage I, "orbital-type" lymphomas that were uniformly treated with photons. All consecutive patients diagnosed with low-grade, Ann Arbor Stage IEA orbital lymphoma treated between 1999 and 2020 at our department were retrospectively reviewed. We excluded patients with exclusive conjunctival involvement, typically treated with en face electrons. In order to quantify radiotherapy related side effects we applied the CTCAE criteria, analyzed changes in visual acuity, quantified dry eye symptoms by use of the Ocular Surface Disease Index (OSDI) score and applied the EORTC QLQ-C30 questionnaire for quality of life (QoL) assessment. In total 66 eyes of 62 patients were irradiated with a median dose of 30.6 Gy. The median follow-up was 43.5 months. The predominant histological subtype were MALT lymphomas. No local failure occurred in this cohort. Of nine outfield relapses, six solely occurred in the contralateral eye. The 5- and 10- years distant progression free survival rates (PFS) were 81.4% and 63.5%. The 5- and 10-years overall survival rates were 85.1% and 71.9% without any tumor related death. Of the acute toxicities none was higher than CTCAE grade 1. The predominant late toxicities were dry eyes (21.2%) of CTCAE Grade <2 and radiation induced cataracts (19.7%). During long-term follow up the average visual acuity did not deteriorate. The global QoL was worst before treatment and improved significantly after 24 months (p = 0.007). External beam radiotherapy of "orbital-type" lymphomas with photons is an effective and gentle treatment option with excellent local control rates. From the high control rates the trend to use slightly lower total doses of 24-27 Gy with conventional fractionation is supported. As non-coplanar radiotherapy techniques improved and total doses can slightly be reduced, the current status of radiotherapy as first line therapy is provided.

ERCC2 gene single-nucleotide polymorphism as a prognostic factor for locally advanced head and neck carcinomas after definitive cisplatin-based radiochemotherapy.

Identifying patients with locally advanced head and neck carcinoma on high risk of recurrence after definitive concurrent radiochemotherapy is of key importance for the selection for consolidation therapy and for individualized treatment intensification. In this multicenter study we analyzed recurrence-associated single-nucleotide polymorphisms (SNPs) in DNA repair genes in tumor DNA from 132 patients with locally advanced head and neck carcinoma (LadHnSCC). Patients were treated with definitive radiotherapy and simultaneous cisplatin-based chemotherapy at six partner sites of the German Cancer Consortium (DKTK) Radiation Oncology Group from 2005 to 2011. For validation, a group of 20 patients was available. Score selection method using proportional hazard analysis and leave-one-out cross-validation were performed to identify markers associated with outcome. The SNPs rs1799793 and rs13181 were associated with survival and the same SNPs and in addition rs17655 with freedom from loco-regional relapse (ffLRR) in the trainings datasets from all patients. The homozygote major rs1799793 genotype at the ERCC2 gene was associated with better (Hazard ratio (HR): 0.418 (0.234-0.744), p = 0.003) and the homozygote minor rs13181 genotype at ERCC2 with worse survival (HR: 2.074, 95% CI (1.177-3.658), p = 0.017) in comparison to the other genotypes. At the ffLRR endpoint, rs1799793 and rs13181 had comparable prognostic value. The rs1799793 and rs13181 genotypes passed the leave-one-out cross-validation procedure and associated with survival and ffLRR in patients with LadHnSCC treated with definitive radiochemotherapy. While findings were confirmed in a small validation dataset, further validation is underway within a prospective biomarker study of the DKTK.

Impact of EBUS-TBNA in addition to [18F]FDG-PET/CT imaging on target volume definition for radiochemotherapy in stage III NSCLC.

PURPOSE/INTRODUCTION: [18F]FDG-PET/CT is the standard imaging-technique for radiation treatment (RT) planning in locally advanced non-small cell lung cancer (NSCLC). The purpose of this study was to examine the additional value of endobronchial-ultrasound transbronchial needle aspiration (EBUS-TBNA) to standard PET/CT for mediastinal lymph-node (LN) staging and its impact on clinical target volume (CTV). MATERIALS AND METHODS: All consecutive patients with primary stage III NSCLC who underwent [18F]FDG-PET/CT and EBUS-TBNA prior to RT were analyzed from 12/2011 to 06/2018. LN-stations were assessed by an expert-radiologist and a nuclear medicine-physician. CTV was evaluated by two independent radiation oncologists. LNs were grouped with increasing distance along the lymphatic chains from primary tumor into echelon-1 (ipsilateral hilum), echelon-2 (LN-station 7 and ipsilateral 4), and echelon-3 (remaining mediastinum and contralateral hilum). RESULTS: A total of 675 LN-stations of which 291 were positive for tumor-cells, were sampled by EBUS-TBNA in 180 patients. The rate of EBUS-positive LNs was 43% among all sampled LNs. EBUS-positivity in EBUS-probed LNs decreased from 85.8% in echelon-1 LNs to 42.4%/ 9.6% in echelon-2/ -3 LNs, respectively (p < 0.0001, Fisher's exact test). The false discovery rate of PET in comparison with EBUS results rose from 5.3% in echelon-1 to 32.9%/ 69.1% in echelon-2/ -3 LNs, respectively (p < 0.0001, Fisher's exact test). Sensitivity and specificity of FDG-PET/CT ranged from 85 to 99% and 67 to 80% for the different echelons. In 22.2% patients, EBUS-TBNA finding triggered changes of the treated CTV, compared with contouring algorithms based on FDG-avidity as the sole criterion for inclusion. CTV was enlarged in 6.7% patients due to EBUS-positivity in PET-negative LN-station and reduced in 15.5% by exclusion of an EBUS-negative but PET-positive LN-station. CONCLUSION: The false discovery rate of [18F]FDG-PET/CT increased markedly with distance from the primary tumor. Inclusion of systematic mediastinal LN mapping by EBUS-TBNA in addition to PET/CT has the potential to increase accuracy of target volume definition, particularly in echelon-3 LNs. EBUS-TBNA is recommended as integral part of staging for radiochemotherapy in stage III NSCLC.

Estimation of radiation exposure of children undergoing superselective intra-arterial chemotherapy for retinoblastoma treatment: assessment of local diagnostic reference levels as a function of age, sex, and interventional success.

PURPOSE: This study aims to determine local diagnostic reference levels (LDRLs) of intra-arterial chemotherapy (IAC) procedures of pediatric patients with retinoblastoma (RB) to provide data for establishing diagnostic reference levels (DRLs) in pediatric interventional radiology (IR). METHODS: In a retrospective study design, LDRLs and achievable dose (AD) were assessed for children undergoing superselective IAC for RB treatment. All procedures were performed at the flat-panel angiography systems (I) ArtisQ biplane (Siemens Healthineers) and (II) Allura Xper (Philips Healthcare). Patients were differentiated according to age (A1: 1-3 months; A2: 4-12 months; A3: 13-72 months; A4: 73 months-10 years; A5: > 10 years), sex, conducted or not-conducted chemotherapy. RESULTS: 248 neurointerventional procedures of 130 pediatric patients (median age 14.5 months, range 5-127 months) with RB (68 unilateral, 62 bilateral) could be included between January 2010 and March 2020. The following diagnostic reference values, AD, and mean values could be determined: (A2) DRL 3.9 Gy cm2, AD 2.9 Gy cm2, mean 3.5 Gy cm2; (A3) DRL 7.0 Gy cm2, AD 4.3 Gy cm2, mean 6.0 Gy cm2; (A4) DRL 14.5 Gy cm2, AD 10.7 Gy cm2, mean 10.8 Gy cm2; (A5) AD 8.8 Gy cm2, mean 8.8 Gy cm2. Kruskal-Wallis-test confirmed a significant dose difference between the examined age groups (A2-A5) (p < 0.001). There was no statistical difference considering sex (p = 0.076) and conducted or not-conducted chemotherapy (p = 0.627). A successful procedure was achieved in 207/248 cases. CONCLUSION: We report on radiation exposure during superselective IAC of a pediatric cohort at the German Retinoblastoma Referral Centre. Although an IAC formally represents a therapeutic procedure, our results confirm that radiation exposure lies within the exposure of a diagnostic interventional procedure. DRLs for superselective IAC are substantially lower compared with DRLs of more complex endovascular interventions.

Scleral necrosis after brachytherapy for uveal melanoma: Analysis of risk factors.

BACKGROUND: Radiation-induced scleral necrosis (RISN) is a rare, but a serious complication of brachytherapy for uveal melanoma. We aimed at analysing the incidence, timing and risk factors associated with development of RISN in a large institutional series. METHODS: All consecutive cases with brachytherapy for uveal melanoma treated by the Departments of Ophthalmology and Radiotherapy at University Hospital Essen between 1999 and 2016 were eligible. Development of RISN during the post-treatment follow-up was recorded. A 1:2 propensity score matched case-control study was performed for the evaluation of the prognostic value of different tumour- and treatment-associated parameters. RESULTS: RISN was documented in 115 (2.9%) of 3960 patients with uveal melanoma included in the final analysis, and occurred at the mean 30.3 months (range: 1.26-226 months) after brachytherapy. In the whole cohort, younger age (p = 0.042), plaque type (p = 0.001) and ciliary body involvement (p < 0.0001) were independently associated with the RISN occurrence. In the case-control study, multivariable weighted proportional hazard analysis discovered the association of the following additional tumour- and treatment-associated characteristics with RISN: posterior tumour margin anterior to equatorial region (p = 0.0003), extraocular tumour extension (p = <0.0001), scleral contact dose (p = <0.0001), conjunctival dehiscence after therapy (p = 0.0001), disinsertion of the superior rectus muscle (p = 0.001) and the glaucoma medication (p = 0.014). CONCLUSIONS: Our study confirms RISN as a rare complication, which might occur even years later after the brachytherapy for uveal melanoma. Alongside with scleral dose five other tumour and therapy related factors predict the risk of RISN after brachytherapy for uveal melanoma were established.

Patterns of cervical lymph node metastasis in supraglottic laryngeal cancer and therapeutic implications of surgical staging of the neck.

PURPOSE: Accurate therapeutic management of the neck is a challenge in patients with supraglottic laryngeal cancer. Nodal metastasis is common at all disease stages, and treatment planning relies on clinical staging of the neck, for both surgical and non-surgical treatment. Here, we compared clinical and surgical staging results in supraglottic carcinoma patients treated with primary surgery to assess the accuracy of pre-therapeutic clinical staging and guide future treatment decisions. METHODS: Retrospective analysis of clinical, pathological, and oncologic outcome data of 70 patients treated with primary surgery and bilateral neck dissection for supraglottic laryngeal cancer. Patients where clinical and pathological neck staging results differed, were identified and analyzed in detail. RESULTS: On pathologic assessment, patients with early stage (pT1/2) primaries showed cervical lymph node metastases in 55% (n = 17/31) of cases, compared to 67% (n = 26/39) of patients with pT3/4 tumors. In 24% (n = 17/70) of all patients, cN status differed from pN status, resulting in an upstaging in 16% of cases (n = 11/70) and a downstaging in 9% (n = 6/70) of cases. 14% of patients with cN0 status had occult metastases (n = 5/30). As assessed by a retrospective tumor board, in case of a non-surgical treatment approach, the inaccurate clinical staging of the neck would have led to an over- or undertreatment of the neck in 20% (n = 14/70) of all patients. CONCLUSION: Our data re-emphasize the high cervical metastasis rates of supraglottic laryngeal cancer across all stages. Inaccurate clinical staging of the neck is common and should be taken into consideration when planning treatment.

Spatial and dosimetric evaluation of residual distortions of prostate and seminal vesicle bed after image-guided definitive and postoperative radiotherapy of prostate cancer with endorectal balloon.

PURPOSE: To quantify daily residual deviations from the planned geometry after image-guided prostate radiotherapy with endorectal balloon and to evaluate their effect on the delivered dose distribution. METHODS: Daily kV-CBCT imaging was used for online setup-correction in six degrees of freedom (6-dof) for 24 patients receiving definitive (12 RTdef patients) or postoperative (12 RTpostop patients) radiotherapy with endorectal balloon (overall 739 CBCTs). Residual deviations were evaluated using several spatial and dosimetric variables, including: (a) posterior Hausdorff distance HDpost (=maximum distance between planned and daily CTV contour), (b) point Pworst with largest HDpost over all fractions, (c) equivalent uniform dose using a cell survival model (EUDSF ) and the generalized EUD concept (gEUDa with parameter a = -7 and a = -20). EUD values were determined for planned ( EUD SF plan ), daily ( EUD SF ind ), and delivered dose distributions ( EUD SF accum ) for plans with 6 mm (=clinical plans) and 2 mm CTV-to-PTV margin. Time series analyses of interfractional spatial and dosimetric deviations were conducted. RESULTS: Large HDpost values ≥ 12.5 mm (≥15 mm) were observed in 20/739 (5/739) fractions distributed across 7 (3) patients. Points Pworst were predominantly located at the posterior CTV boundary in the seminal vesicle region (16/24 patients, 6/7 patients with HDpost  ≥ 12.5 mm). Time series analyses revealed a stationary white noise characteristic of HDpost and relative dose at Pworst . The EUDSF difference between planned and accumulated dose distributions was < 5.4% for all 6-mm plans. Evaluating 2-mm plans, EUDSF deteriorated by < 10% (<5%) in 75% (58.5%) of the patients. EUD SF accum was well described by the median value of the EUD SF ind distribution. PTV margin calculation at Pworst yielded 8.8 mm. CONCLUSIONS: Accumulated dose distributions in prostate radiotherapy with endorectal balloon are forgiving of considerable residual distortions after 6-dof patient setup if they are observed in a minority of fractions and the median value of EUD SF ind determined per fraction stays within 95% of prescribed dose. Common PTV margin calculations are overly conservative because after online correction of translational and rotational errors only residual deformations need to be included. These results provide guidelines regarding online navigation, margin optimization, and treatment adaptation strategies.

Dosimetric impact of the positioning variation of tumor treating field electrodes in the PriCoTTF-phase I/II trial.

PURPOSE: The aim of the present study based on the PriCoTTF-phase I/II trial is the quantification of skin-normal tissue complication probabilities of patients with newly diagnosed glioblastoma multiforme treated with Tumor Treating Field (TTField) electrodes, concurrent radiotherapy, and temozolomide. Furthermore, the skin-sparing effect by the clinically applied strategy of repetitive transducer array fixation around their center position shall be examined. MATERIAL AND METHODS: Low-dose cone-beam computed tomography (CBCT) scans of all fractions of the first seven patients of the PriCoTTF-phase I/II trial, used for image guidance, were applied for the dosimetric analysis, for precise TTField transducer array positioning and contour delineation. Within this trial, array positioning was varied from fixation-to-fixation period with a standard deviation of 1.1 cm in the direction of the largest variation of positioning and 0.7 cm in the perpendicular direction. Physical TTField electrode composition was examined and a respective Hounsfield Unit attributed to the TTField electrodes. Dose distributions in the planning CT with TTField electrodes in place, as derived from prefraction CBCTs, were calculated and accumulated with the algorithm Acuros XB. Dose-volume histograms were obtained for the first and second 2 mm scalp layer with and without migrating electrodes and compared with those with fixed electrodes in an average position. Skin toxicity was quantified according to Lyman's model. Minimum doses in hot-spots of 0.05 cm2 and 25 cm2 ( Δ D0.05cm 2 , Δ D25cm 2 ) size in the superficial skin layers were analyzed. RESULTS: Normal tissue complication probabilities (NTCPs) for skin necrosis ranged from 0.005% to 1.474% (median 0.111%) for the different patients without electrodes. NTCP logarithms were significantly dependent on patient (P < 0.0001) and scenario (P < 0.0001) as classification variables. Fixed positioning of TTField arrays increased skin-NTCP by a factor of 5.50 (95%, CI: 3.66-8.27). The variation of array positioning increased skin-NTCP by a factor of only 3.54 (95%, CI: 2.36-5.32) (P < 0.0001, comparison to irradiation without electrodes; P = 0.036, comparison to irradiation with fixed electrodes). NTCP showed a significant rank correlation with D25cm2 over all patients and scenarios (rs  = 0.76; P < 0.0001). CONCLUSION: Skin-NTCP calculation uncovers significant interpatient heterogeneity and may be used to stratify patients into high- and low-risk groups of skin toxicity. Array position variation may mitigate about one-third of the increase in surface dose and skin-NTCP by the TTField electrodes.

Brachytherapy for Peripheral Retinal Capillary Haemangioblastoma in von Hippel-Lindau Disease. / Brachytherapie peripherer retinaler kapillärer Hämangioblastome beim Von-Hippel-Lindau-Syndrom.

AIM: To report our experience with 106ruthenium-brachytherapy of peripheral capillary haemangioblastomas in patients with von Hippel-Lindau disease. DESIGN: Retrospective case series. METHODS: A total of 53 haemangioblastomas, treated with 106ruthenium-brachytherapy, were included in our study. The applied radiation dose, visual outcome, angioma activity, need for vitreoretinal surgery and incidence of secondary complications such as macular oedema, secondary glaucoma, vitreous haemorrhage, and epiretinal gliosis were assessed. RESULTS: All treated eyes could be preserved. In 11 patients (20.8%), single brachytherapy did not achieve complete inactivation of the tumour. 31% developed macular oedema postoperatively. Tractional retinal detachment developed in 23.8%, and epiretinal gliosis was observed in 2.4% of patients. Vitreoretinal surgery was necessary in 50% of all treated eyes. At the end of the follow-up, 40.5% of all treated eyes achieved visual acuity (VA) of 0.6 or better, and one third reached a VA of less than 0.1. Mean irradiation dose to the tumour apex was 144 Gy. Higher apex doses correlated with better tumour control of irradiated haemanigoblastomas and lower complication rates. CONCLUSIONS: Brachytherapy of peripheral retinal capillary haemangioblastomas is an effective treatment modality. Higher irradiation doses seem to lead to more successful treatment.

Pretreatment metabolic tumour volume in stage IIIA/B non-small-cell lung cancer uncovers differences in effectiveness of definitive radiochemotherapy schedules: analysis of the ESPATUE randomized phase 3 trial.

PURPOSE: According to the ACRIN 6668/RTOG 0235 trial, pretreatment metabolic tumour volume (MTV) as detected by 18F-fluorodeoxyglucose PET/CT is a prognostic factor in patients with stage III non-small-cell lung cancer (NSCLC) after definitive radiochemotherapy (RCT). To validate the prognostic value of MTV in patients with stage III NSCLC after RCT, we analysed mature survival data from the German phase III trial ESPATUE. METHODS: This analysis included patients who were staged by PET/CT and who were enrolled in the ESPATUE trial, a randomized study comparing definitive RCT (arm A) with surgery (arm B) after induction chemotherapy and RCT in patients with resectable stage IIIA/IIIB NSCLC. Patients refusing surgery and those with nonresectable disease were scheduled to receive definitive RCT. MTV was measured using a fixed threshold-based approach and a model-based iterative volume thresholding approach. Data were analysed using proportional hazards models and Kaplan-Meier survival functions. RESULTS: MTV as a continuous variable did not reveal differences in survival between the 117 patients scheduled to receive definitive RCT and all 169 enrolled patients who underwent pretreatment PET/CT (p > 0.5). Five-year survival rates were 33% (95% CI 17-49%) in patients scheduled for definitive RCT with a high MTV (>95.4 ml) and 32% (95% CI: 22-42%) in those with a low MTV. The hazard ratio for survival was 0.997 (95% CI 0.973-1.022) per 10-ml increase in MTV and the slope was significantly shallower than that in the ACRIN 6668/RTOG 0235 trial (random effects model, p = 0.002). There were no differences in MTV size distributions between the ACRIN and ESPATUE trials (p = 0.97). CONCLUSION: Patients with stage III NSCLC and a large MTV in whom definitive RCT had a particularly good survival in the ESPATUE trial. Treatment individualization according to MTV is not supported by this study. The ESPATUE and ACRIN trials differed by the use of cisplatin-containing induction chemotherapy and an intensified radiotherapy regimen that were particularly effective in patients with large MTV disease.

Talazoparib enhances resection at DSBs and renders HR-proficient cancer cells susceptible to Polθ inhibition.

BACKGROUND AND PURPOSE: The PARP inhibitor (PARPi), Talazoparib (BMN673), effectively and specifically radiosensitizes cancer cells. Radiosensitization is mediated by a shift in the repair of ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) toward PARP1-independent, alternative end-joining (alt-EJ). DNA polymerase theta (Polθ) is a key component of this PARP1-independent alt-EJ pathway and we show here that its inhibition can further radiosensitize talazoparib-treated cells. The purpose of the present work is to explore mechanisms and dynamics underpinning enhanced talazoparib radiosensitization by Polθ inhibitors in HR-proficient cancer cells. METHODS AND MATERIALS: Radiosensitization to PARPis, talazoparib, olaparib, rucaparib and veliparib was assessed by clonogenic survival. Polθ-proficient and -deficient cells were treated with PARPis and/or with the Polθ inhibitors ART558 or novobiocin. The role of DNA end-resection was studied by down-regulating CtIP and MRE11 expression using siRNAs. DSB repair was assessed by scoring γH2AX foci. The formation of chromosomal abnormalities was assessed as evidence of alt-EJ function using G2-specific cytogenetic analysis. RESULTS: Talazoparib exerted pronounced radiosensitization that varied among the tested cancer cell lines; however, radiosensitization was undetectable in normal cells. Other commonly used PARPis, olaparib, veliparib, or rucaparib were ineffective radiosensitizers under our experimental conditions. Although genetic ablation or pharmacological inhibition of Polθ only mildly radiosensitized cancer cells, talazoparib-treated cells were markedly further radiosensitized. Mechanistically, talazoparib shunted DSBs to Polθ-dependent alt-EJ by enhancing DNA end-resection in a CtIP- and MRE11-dependent manner - an effect detectable at low, but not high IR doses. Chromosomal translocation analysis in talazoparib-treated cells exposed to Polθ inhibitors suggested that PARP1- and Polθ-dependent alt-EJ pathways may complement, but also back up each other. CONCLUSION: We propose that talazoparib promotes low-dose, CtIP/MRE11-dependent resection and increases the reliance of irradiated HR-proficient cancer cells, on Polθ-mediated alt-EJ. The combination of Polθ inhibitors with talazoparib suppresses this option and causes further radiosensitization. The results suggest that Polθ inhibition may be exploited to maximize talazoparib radiosensitization of HR-proficient tumors in the clinic.

Prospects for online adaptive radiation therapy (ART) for head and neck cancer.

BACKGROUND: The aim of the present study is to examine the impact of kV-CBCT-based online adaptive radiation therapy (ART) on dosimetric parameters in comparison to image-guided-radiotherapy (IGRT) in consecutive patients with tumors in the head and neck region from a prospective registry. METHODS: The study comprises all consecutive patients with tumors in the head and neck area who were treated with kV-CBCT-based online ART or IGRT-modus at the linear-accelerator ETHOS™. As a measure of effectiveness, the equivalent-uniform-dose was calculated for the CTV (EUDCTV) and organs-at-risk (EUDOAR) and normalized to the prescribed dose. As an important determinant for the need of ART the interfractional shifts of anatomic landmarks related to the tongue were analyzed and compared to the intrafractional shifts. The latter determine the performance of the adapted dose distribution on the verification CBCT2 postadaptation. RESULTS: Altogether 59 consecutive patients with tumors in the head-and-neck-area were treated from 01.12.2021 to 31.01.2023. Ten of all 59 patients (10/59; 16.9%) received at least one phase within a treatment course with ART. Of 46 fractions in the adaptive mode, irradiation was conducted in 65.2% of fractions with the adaptive-plan, the scheduled-plan in the remaining. The dispersion of the distributions of EUDCTV-values from the 46 dose fractions differed significantly between the scheduled and adaptive plans (Ansari-Bradley-Test, p = 0.0158). Thus, the 2.5th percentile of the EUDCTV-values by the adaptive plans amounted 97.1% (95% CI 96.6-99.5%) and by the scheduled plans 78.1% (95% CI 61.8-88.7%). While the EUDCTV for the accumulated dose distributions stayed above 95% at PTV-margins of ≥ 3 mm for all 8 analyzed treatment phases the scheduled plans did for margins ≥ 5 mm. The intrafractional anatomic shifts of all 8 measured anatomic landmarks were smaller than the interfractional with overall median values of 8.5 mm and 5.5 mm (p < 0.0001 for five and p < 0.05 for all parameters, pairwise comparisons, signed-rank-test). The EUDOAR-values for the larynx and the parotid gland were significantly lower for the adaptive compared with the scheduled plans (Wilcoxon-test, p < 0.001). CONCLUSIONS: The mobile tongue and tongue base showed considerable interfractional variations. While PTV-margins of 5 mm were sufficient for IGRT, ART showed the potential of decreasing PTV-margins and spare dose to the organs-at-risk.