Symptom relief, prognostic factors, and outcome in patients receiving urgent radiation therapy for superior vena cava syndrome : A single-center retrospective analysis of 21 years' practice.

PURPOSE: Superior vena cava syndrome (SVCS) often results from external vessel compression due to tumor growth. Urgent symptom-guided radiotherapy (RT) remains a major treatment approach in histologically proven, rapidly progressive disease. Despite several publications, recent data concerning symptom relief and oncological outcome as well as potential confounders in treatment response are still scarce. METHODS: We performed a retrospective single-center analysis of patients receiving urgent RT between 2000 and 2021 at the University Medical Center Göttingen. Symptom relief was evaluated by CTCAE score during the RT course. Effects of variables on symptom relief were assessed by logistic regression. The impact of parameters on overall survival (OS) was evaluated using Kaplan-Meier plot along with the log-rank test and by Cox regression analyses. Statistically significant (p-value < 0.05) confounders were tested in multivariable analyses. RESULTS: A total of 79 patients were included. Symptom relief was achieved in 68.4%. Mean OS was 59 days, 7.6% (n = 6) of patients showed long-term survival (> 2 years). Applied RT dose > 39 Gy, clinical target volume (CTV) size < 387 ml, concomitant chemotherapy, and completion of the prescribed RT course were found to be statistically significant for OS; applied RT dose and completion of the prescribed RT course were found to be statistically significant for symptom relief. CONCLUSION: Symptom relief by urgent RT for SVCS was achieved in the majority of patients. RT dose and completion of the RT course were documented as predictors for OS and symptom relief, CTV < 387 ml and concomitant chemotherapy were predictive for OS.

And Yet It Moves: Clinical Outcomes and Motion Management in Stereotactic Body Radiation Therapy (SBRT) of Centrally Located Non-Small Cell Lung Cancer (NSCLC): Shedding Light on the Internal Organ at Risk Volume (IRV) Concept.

The internal organ at risk volume (IRV) concept might improve toxicity profiles in stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC). We studied (1) clinical aspects in central vs. peripheral tumors, (2) the IRV concept in central tumors, (3) organ motion, and (4) associated normal tissue complication probabilities (NTCPs). We analyzed patients who received SBRT for NSCLC (clinical aspects, n = 78; motion management, n = 35). We found lower biologically effective doses, larger planning target volume sizes, higher lung doses, and worse locoregional control for central vs. peripheral tumors. Organ motion was greater in males and tall patients (bronchial tree), whereas volume changes were lower in patients with a high body mass index (BMI) (esophagus). Applying the IRV concept (retrospectively, without new optimization), we found an absolute increase of >10% in NTCPs for the bronchial tree in three patients. This study emphasizes the need to optimize methods to balance dose escalation with toxicities in central tumors. There is evidence that organ motion/volume changes could be more pronounced in males and tall patients, and less pronounced in patients with higher BMI. Since recent studies have made efforts to further subclassify central tumors to refine treatment, the IRV concept should be considered for optimal risk assessment.