Addressing challenges in low-income and middle-income countries through novel radiotherapy research opportunities.

Although radiotherapy continues to evolve as a mainstay of the oncological armamentarium, research and innovation in radiotherapy in low-income and middle-income countries (LMICs) faces challenges. This third Series paper examines the current state of LMIC radiotherapy research and provides new data from a 2022 survey undertaken by the International Atomic Energy Agency and new data on funding. In the context of LMIC-related challenges and impediments, we explore several developments and advances-such as deep phenotyping, real-time targeting, and artificial intelligence-to flag specific opportunities with applicability and relevance for resource-constrained settings. Given the pressing nature of cancer in LMICs, we also highlight some best practices and address the broader need to develop the research workforce of the future. This Series paper thereby serves as a resource for radiation professionals.

Clinical factors and major pathological response after neoadjuvant chemoimmunotherapy in potentially resectable lung squamous cell carcinoma.

Objective: Major pathological response (MPR) helps evaluate the prognosis of patients with lung squamous cell carcinoma (LUSC). However, the clinical factors that affect the achievement of MPR after neoadjuvant chemoimmunotherapy (NCIO) in patients with LUSC remain unclear. This study aimed to explore the clinical factors affecting the MPR after NCIO in patients with potentially resectable LUSC. Methods: This retrospective study included patients with stage IIB-IIIC LUSC who underwent surgical resection after receiving NCIO at a center between March 2020 and November 2022. In addition to the postoperative pathological remission rate, sex, age, body mass index (BMI), smoking history, TNM stage, hematological and imaging test results, and other indicators were examined before NCIO. According to the pathological response rate of the surgically removed tumor tissue, the patients were split into MPR and non-MPR groups. Results: In total, 91 LUSC patients who met the study's eligibility criteria were enrolled: 32 (35%) patients in the non-MPR group and 59 (65%) in the MPR group, which included 43 cases of pathological complete remission (pCR). Pre-treatment lymphocyte level (LY) (odds ratio [OR] =5.997), tumor burden (OR=0.958), N classification (OR=15.915), radiographic response (OR=11.590), pulmonary atelectasis (OR=5.413), and PD-L1 expression (OR=1.028) were independently associated with MPR (all P < 0.05). Based on these six independent predictors, we developed a nomogram model of prediction having an area under the curve (AUC) of 0.914 that is simple to apply clinically to predict the MPR. The MPR group showed greater disease-free survival (DFS) than the non-MPR group, according to the survival analysis (P < 0.001). Conclusion: The MPR rate of NCIO for potentially resectable LUSC was 65%. LY, tumor burden, N classification, radiographic response, pulmonary atelectasis, and PD-L1 expression in patients with LUSC before NCIO were the independent and ideal predictors of MPR. The developed nomogram demonstrated a good degree of accuracy and resilience in predicting the MPR following NCIO, indicating that it is a useful tool for assuring customized therapy for patients with possibly resectable LUSC.

Survival Outcome Analysis of Stereotactic Body Radiotherapy and Immunotherapy (SBRT-IO) versus SBRT-Alone in Unresectable Hepatocellular Carcinoma.

Introduction: While combination of stereotactic body radiotherapy (SBRT) and immunotherapy are promising, their efficacy and safety have not been compared with SBRT-alone in patients with unresectable hepatocellular carcinoma (HCC). Methods: This retrospective study included 100 patients with nonmetastatic, unresectable HCC in two hospitals. Eligible patients had tumor nodules ≤3 and Child-Pugh liver function score of A5 to B7. Seventy patients received SBRT-alone, and 30 patients underwent combined SBRT and immunotherapy (SBRT-IO). Overall survival (OS), time to progression (TTP), overall response rate (ORR), and toxicity were analyzed. We adjusted for the potential confounding factors using propensity score matching. Results: The median tumor size was 7.3 cm (range, 2.6-18 cm). Twenty-five (25%) of patients had vascular invasion. Before propensity score matching, the 1-year and 3-year OS rate was 89.9% and 59.8% in the SBRT-IO group and 75.7% and 42.3% in SBRT-alone group (p = 0.039). After propensity score matching (1:2), 25 and 50 patients were selected from the SBRT-IO and SBRT-alone group. The 1-year and 3-year OS was 92.0% and 63.9% in the SBRT-IO group versus 74.0% and 43.3% in the SBRT-alone group (p = 0.034). The 1-year and 3-year TTP was better in SBRT-IO group (1-year: 68.9% vs. 58.9% and 3-year: 61.3% vs. 32.5%, p = 0.057). The ORR of 88% (complete response [CR]: 56%, partial response [PR]: 22%) in SBRT-IO arm was significantly better than 50% (CR: 20%, PR: 30%) in the SBRT-alone arm (p = 0.006). Three patients (12%) developed ≥grade 3 immune-related treatment adverse events (n = 2 hepatitis, n = 1 dermatitis) leading to permanent treatment discontinuation. Conclusion: Adding immunotherapy to SBRT resulted in better survival with manageable toxicities. Prospective randomized trial is warranted.

Radiotherapy for small cell lung cancer in current clinical practice guidelines.

Several guidelines including radiotherapy recommendations exist worldwide for the treatment of small cell lung cancer (SCLC). To evaluate the differences in radiotherapy recommendations we conducted a systematic review. PubMed and the sites of medical societies were searched for SCLC guidelines published in either English, Chinese, or Dutch. This was limited to January 2018 till February 2021 to only include up-to-date recommendations. Data was extracted and compared regarding the guideline's development method and radiotherapy recommendations. Eleven guidelines were identified (PubMed n=4, societies n=7) from Spain (n=1), Canada (n=1), America (n=3), United Kingdom (n=1), the Netherlands (n=1), and China (n=3), respectively. Nine guidelines assessed the strength of evidence (SOE) and specified the strength of recommendation (SOR), although methods were different. The major radiotherapy recommendations are similar although differences exist in thoracic radiotherapy (TRT) dose, time, and volume. Controversial areas are TRT in resected stage I-IIA (pN1), prophylactic cranial irradiation (PCI) in resected as well as unresected stage I-IIA, stereotactic body radiation therapy (SBRT) in unresected stage I-IIA, PCI time, and PCI versus magnetic resonance imaging (MRI) surveillance in stage IV. The existence of several overlapping guidelines for SCLC treatment indicates that guideline development is (unnecessarily) repeated by different organizations or societies. Improvement could be made by better international collaboration to avoid duplicating unnecessary work, which would spare a lot of time and resources. Efforts should be made to work together on controversial or unknown fields.

The role of stereotactic body radiotherapy in hepatocellular carcinoma: guidelines and evidences.

Hepatocellular carcinoma (HCC) is a common malignancy with high mortality rates. While surgery can be curative in early-stage disease, 80% of patients cannot undergo surgical resection. Stereotactic body radiotherapy (SBRT), an emerging, non-invasive, precision treatment, has shown promising results across various stages of HCC and has thus been adopted in practice to varying degrees around the world. This article aims to review current guideline recommendations on SBRT, clinical evidence, and outcome comparisons with other local treatment modalities. Attempts are also made to compare the differences in clinical trials between Asian and Western countries.