Regression of all untreated lesions in multifocal low-grade meningioma following fractionated stereotactic radiotherapy-abscopal effect or spontaneous regression? : Case report and review of the literature.

PURPOSE: Abscopal effects have been reported predominantly in metastatic cancers, indicating a radiographic response in a lesion that has not been included in the radiotherapy target volume. The response is interpreted as a humoral immune response to radiotherapy-generated tumour-specific antigens. In this case study, we present the first histologically confirmed multifocal low-grade meningioma with spontaneous regression of all other lesions after conventionally fractionated stereotactic radiotherapy (RT). CASE REPORT: Two localisations, right frontal and right spheno-orbital, were resected at the time of the initial diagnosis in a 66-year-old woman. RT was performed 1 year later to a progressive occipital lesion at the cerebral falx. RESULTS: Regular magnetic resonance imaging (MRI) showed slightly decreasing tumour volume in untreated lesions 1 year after RT and continued during further follow-up. Up to > 7 years after treatment, MRI demonstrated an almost complete response of all initial lesions. Two prior reports with meningioma were published in one patient with an atypical meningioma after conventionally fractionated RT and another patient with an intracranial meningiomatosis after radiosurgery. CONCLUSION: This case study supports the concepts of treating only progressive or symptomatic meningioma lesions locally and careful regular MRI surveillance for further assessment. Potential active interventions to trigger an abscopal effect are currently not known. Further research of this beneficial effect for our patients should be supported.

Long-Term Comparative Study on the Local Tumour Control of Different Ablation Technologies in Primary and Secondary Liver Malignancies.

Purpose: To evaluate local tumour control (LTC) by local ablation techniques (LAT) in liver malignancies. Materials and methods: In patients treated with LAT between January 2013 and October 2020 target lesions were characterised by histology, dimensions in three spatial axes, volume, vascularisation and challenging (CL) location. LAT used were: Radiofrequency Ablation (RFA), Microwave Ablation (MWA), Cryoablation (CRYO), Electrochemotherapy (ECT), and Interstitial Brachytherapy (IBT). Results: 211 LAT were performed in 155 patients. Mean follow-up including MRI for all patients was 11 months. Lesions treated with ECT and IBT were significantly larger and significantly more often located in CL in comparison to RFA, MWA and CRYO. Best LTC (all data for 12 months are given below) resulted after RFA (93%), followed by ECT (81%), CRYO (70%), IBT (68%) and MWA (61%), and further, entity-related for HCC (93%), followed by CRC (83%) and BrC (72%), without statistically significant differences. LTC in hypovascular lesions was worse (64%), followed by intermediate (82% p = 0.01) and hypervascular lesions (92% p = 0.07). Neither diameter (<3 cm: 81%/3−6 cm: 74%/>6 cm: 70%), nor volume (<10 cm3: 80%/10−20 cm3: 86%/>20 cm3: 67%), nor CL (75% in CL vs. 80% in non CL) had a significant impact on LTC. In CL, best LTC resulted after ECT (76%) and IBT (76%). Conclusion: With suitable LAT, similarly good local tumour control can be achieved regardless of lesion size and location of the target.

Radiomics for prediction of radiation-induced lung injury and oncologic outcome after robotic stereotactic body radiotherapy of lung cancer: results from two independent institutions.

OBJECTIVES: To generate and validate state-of-the-art radiomics models for prediction of radiation-induced lung injury and oncologic outcome in non-small cell lung cancer (NSCLC) patients treated with robotic stereotactic body radiation therapy (SBRT). METHODS: Radiomics models were generated from the planning CT images of 110 patients with primary, inoperable stage I/IIa NSCLC who were treated with robotic SBRT using a risk-adapted fractionation scheme at the University Hospital Cologne (training cohort). In total, 199 uncorrelated radiomic features fulfilling the standards of the Image Biomarker Standardization Initiative (IBSI) were extracted from the outlined gross tumor volume (GTV). Regularized models (Coxnet and Gradient Boost) for the development of local lung fibrosis (LF), local tumor control (LC), disease-free survival (DFS) and overall survival (OS) were built from either clinical/ dosimetric variables, radiomics features or a combination thereof and validated in a comparable cohort of 71 patients treated by robotic SBRT at the Radiosurgery Center in Northern Germany (test cohort). RESULTS: Oncologic outcome did not differ significantly between the two cohorts (OS at 36 months 56% vs. 43%, p = 0.065; median DFS 25 months vs. 23 months, p = 0.43; LC at 36 months 90% vs. 93%, p = 0.197). Local lung fibrosis developed in 33% vs. 35% of the patients (p = 0.75), all events were observed within 36 months. In the training cohort, radiomics models were able to predict OS, DFS and LC (concordance index 0.77-0.99, p < 0.005), but failed to generalize to the test cohort. In opposite, models for the development of lung fibrosis could be generated from both clinical/dosimetric factors and radiomic features or combinations thereof, which were both predictive in the training set (concordance index 0.71- 0.79, p < 0.005) and in the test set (concordance index 0.59-0.66, p < 0.05). The best performing model included 4 clinical/dosimetric variables (GTV-Dmean, PTV-D95%, Lung-D1ml, age) and 7 radiomic features (concordance index 0.66, p < 0.03). CONCLUSION: Despite the obvious difficulties in generalizing predictive models for oncologic outcome and toxicity, this analysis shows that carefully designed radiomics models for prediction of local lung fibrosis after SBRT of early stage lung cancer perform well across different institutions.

Interstitial single fraction brachytherapy for malignant pulmonary tumours.

PURPOSE: Interstitial brachytherapy for pulmonary tumours is an alternative to stereotactic radiotherapy, allowing high conformity despite it being an invasive technique. The aim of the study was the analysis of dose distribution, toxicity and tumour response rates. METHODS: In the years 2014-2019, 27 patients with pulmonary tumours received 36 interstitial brachytherapies with Ir-192: 11 patients with non-small cell lung cancer, 16 patients with pulmonary metastases of other entities. RESULTS: Patients were treated with a median (interquartile range) prescription dose of 20 (20-26) Gy in a single fraction. Mean lung dose to the ipsilateral lung was 2.8 (1.6-4.7) Gy. Maximum doses to the heart, oesophagus, thoracic wall and spinal cord were 2.4 (1.8-4.6) Gy, 2.0 (1.2-6.2) Gy, 12.6 (8.0-18.2) Gy and 1.5 (0.6-3.9) Gy. Median survival after treatment was 15 months, with a 1- and 2­year local control of 84% and 60%. Median overall survival after initial cancer diagnosis was 94 months; 2 years following brachytherapy, 75% of patients with colorectal cancer vs. 37% with other histologies were alive; p = 0.14. In 69% (n = 25), brachytherapy could be performed without acute complications. A self-limiting bleeding occurred in 8% (n = 3), fever in 3% (n = 1), pneumothorax in 17% (n = 6), and pulmonary failure in 3% (n = 1). Patients with > 20 Gy in 95% of planning target volume had higher pneumothorax rates needing intervention (31% vs. 5%, p = 0.04). CONCLUSIONS: Interstitial brachytherapy for pulmonary tumours is a highly conformal therapy with minimal doses to the organs at risk. For the majority of patients, treatment can be performed without relevant complications in a single fraction with a satisfactory local control.

Low risk of contralateral lymph node recurrence in lateralized head and neck carcinoma after postoperative ipsilateral radiotherapy.

PURPOSE: The role of postoperative irradiation to contralateral non-involved neck nodes in lateralized carcinoma of the head and neck is not clear. The contralateral neck failure rate in head and neck carcinoma treated postoperatively with ipsilateral neck irradiation only was evaluated. METHODS: Patients with carcinoma of the oral cavity, oropharynx, or hypopharynx without midline extension treated between 1990 and 2016 were analyzed. After tumor resection and neck dissection (ND), radiotherapy was given to the primary tumor site and ipsilateral neck. High-risk patients additionally received concurrent chemotherapy. Freedom from contralateral neck recurrence (FCNR), locoregional control rate (LRC), overall survival (OS), and disease-free survival (DFS) were evaluated. RESULTS: 197 patients (median age 60.7 years, 66.5% males, 52.8% oropharyngeal carcinomas) were analyzed. Complete resection (R0) was achieved in 85.8% of cases. Ipsilateral ND was performed in all patients and contralateral ND in 144 patients (73.1%). Concurrent chemotherapy was given to 59 patients (30.0%). After a median follow-up of 45.5 months, OS and DFS of all patients were 73.6% and 70.9% at 5 years, respectively. A total of 45 patients (22.8%) suffered from a locoregional recurrence, lymph node metastases of the contralateral neck developed in 12 patients (6.1%) only. There was no significant difference in contralateral nodal failure rate with or without performance of contralateral ND. CONCLUSION: Regional failure of the contralateral neck was low after surgery and ipsilateral neck irradiation in head and neck carcinomas without midline extension, supporting evidence that contralateral neck radiotherapy can safely be omitted in selected cases.

Radiomic analysis of planning computed tomograms for predicting radiation-induced lung injury and outcome in lung cancer patients treated with robotic stereotactic body radiation therapy.

OBJECTIVES: To predict radiation-induced lung injury and outcome in non-small cell lung cancer (NSCLC) patients treated with robotic stereotactic body radiation therapy (SBRT) from radiomic features of the primary tumor. METHODS: In all, 110 patients with primary stage I/IIa NSCLC were analyzed for local control (LC), disease-free survival (DFS), overall survival (OS) and development of local lung injury up to fibrosis (LF). First-order (histogram), second-order (GLCM, Gray Level Co-occurrence Matrix) and shape-related radiomic features were determined from the unprocessed or filtered planning CT images of the gross tumor volume (GTV), subjected to LASSO (Least Absolute Shrinkage and Selection Operator) regularization and used to construct continuous and dichotomous risk scores for each endpoint. RESULTS: Continuous scores comprising 1-5 histogram or GLCM features had a significant (p = 0.0001-0.032) impact on all endpoints that was preserved in a multifactorial Cox regression analysis comprising additional clinical and dosimetric factors. At 36 months, LC did not differ between the dichotomous risk groups (93% vs. 85%, HR 0.892, 95%CI 0.222-3.590), while DFS (45% vs. 17%, p < 0.05, HR 0.457, 95%CI 0.240-0.868) and OS (80% vs. 37%, p < 0.001, HR 0.190, 95%CI 0.065-0.556) were significantly lower in the high-risk groups. Also, the frequency of LF differed significantly between the two risk groups (63% vs. 20% at 24 months, p < 0.001, HR 0.158, 95%CI 0.054-0.458). CONCLUSION: Radiomic analysis of the gross tumor volume may help to predict DFS and OS and the development of local lung fibrosis in early stage NSCLC patients treated with stereotactic radiotherapy.

Risk-adapted robotic stereotactic body radiation therapy for inoperable early-stage non-small-cell lung cancer.

PURPOSE: To evaluate efficacy and toxicity of stereotactic body radiation therapy (SBRT) with CyberKnife® (Accuray, Sunnyvale, CA, USA) in a selected cohort of primary, medically inoperable early-stage non-small cell lung cancer (NSCLC) patients. METHODS: From 2012 to 2016, 106 patients (median age 74 years, range 50-94 years) with primary NSCLC were treated with SBRT using CyberKnife®. Histologic confirmation was available in 87 patients (82%). For mediastinal staging, 92 patients (87%) underwent 18F-fluorodeoxyglucose positron-emission tomography (18-FDG-PET) and/or endobronchial ultrasound (EBUS)-guided lymph node biopsy or mediastinoscopy. Tumor stage (UICC8, 2017) was IA/B (T1a-c, 1-3 cm) in 86 patients (81%) and IIA (T2a/b, 3-5 cm) in 20 patients (19%). Depending on tumor localization, three different fractionation schedules were used: 3 fractions of 17Gy, 5 fractions of 11Gy, or 8 fractions of 7.5 Gy. Tracking was based on fiducial implants in 13 patients (12%) and on image guidance without markers in 88%. RESULTS: Median follow-up was 15 months (range 0.5-46 months). Acute side effects were mild (fatigue grade 1-2 in 20% and dyspnea grade 1-2 in 17%). Late effects were observed in 4 patients (4%): 3 patients developed pneumonitis requiring therapy (grade 2) and 1 patient suffered a rib fracture (grade 3). In total, 9/106 patients (8%) experienced a local recurrence, actuarial local control rates were 88% (95% confidence interval, CI, 80-96%) at 2 years and 77% (95%CI 56-98%) at 3 years. The median disease-free survival time was 27 months (95%CI 23-31 months). Overall survival was 77% (95%CI 65-85%) at 2 years and 56% (95%CI 39-73%) at 3 years. CONCLUSION: CyberKnife® lung SBRT which allows for real-time tumor tracking and risk-adapted fractionation achieves satisfactory local control and low toxicity rates in inoperable early-stage primary lung cancer patients.

Prognostic impact of human papillomavirus status, survivin, and epidermal growth factor receptor expression on survival in patients treated with radiochemotherapy for very advanced nonresectable oropharyngeal cancer.

BACKGROUND: The influence of human papillomavirus (HPV) status on survival for patients with very advanced inoperable oropharyngeal SCC treated with radiochemotherapy (RCT) was studied. METHODS: Patients received either 69.2 Gy with concomitant boost (ccb) or 70 Gy conventionally fractionated (cf), weekly paclitaxel 40 mg/m(2), and carboplatin area under the concentration-time curve (AUC) 1. Tumor was analyzed for the presence of high-risk HPV-DNA using polymerase chain reaction (PCR) and direct DNA sequencing. p16-expression, survivin, and epidermal growth factor receptor (EGFR) expression were evaluated by immunohistochemistry and influence on survival was calculated. RESULTS: Of 52 patients, 25.0% were HPV positive and 75.0% HPV negative. The 2-year progression-free survival (PFS) was 70.1% for p16-positive patients and 37.1% for p16-negative patients (p = .005). The 3-year overall survival (OS) rate was 43.9% for all patients and did not significantly differ between the groups. Neither survivin nor EGFR expression influenced PFS or OS significantly. CONCLUSIONS: HPV status influences PFS in patients with advanced, nonresectable tumor stages but not OS. Additional risk factors seem to have a stronger influence on survival than HPV status.

Definitive radiochemotherapy of advanced head and neck cancer with carboplatin and paclitaxel : a phase II study.

PURPOSE: To report outcome and toxicity of concurrent radiochemotherapy with carboplatin and paclitaxel in advanced squamous cell carcinomas of the oropharynx and hypopharynx. PATIENTS AND METHODS: Advanced inoperable carcinomas of the oropharynx and hypopharynx were treated with either hyper-fractionated, accelerated radiotherapy (50.0 Gy/2.0 with concomitant boost to 69.2 Gy/1.6) or conventional fractionated radiotherapy (70.2-72 Gy/1.8) concurrent with paclitaxel 40 mg/m2 and carboplatin AUC 1 weekly for 6 weeks. Acute and long-term toxicity was measured according to WHO- and CTC-criteria. RESULTS: A total of 84 patients were included between 2000 and 2008. Median follow-up time of patients alive was 36 months. Conventionally fractionated radiotherapy was given to 16 patients, while 68 patients were treated with concomitant boost. Finally, 88.1% of patients received full dose paclitaxel. Acute mucositis ≥ grade 3 was present in 51.2% of patients, while 6% of patients experienced ≥ grade 3 leucopenia and thrombopenia. A supportive gastric feeding tube was implanted in 89.1% of patients. Overall survival after 2 years was 46.3%, progression-free survival after 2 years was 41.0%. There was no significant survival difference between the different radiotherapy protocols. CONCLUSION: Concomitant carboplatin and paclitaxel is feasible and effective in advanced carcinomas of the head and neck.