MR-LINAC, a New Partner in Radiation Oncology: Current Landscape.

Technological advances in radiation oncology are oriented towards improving treatment precision and tumor control. Among these advances, magnetic-resonance-image-guided radiation therapy (MRgRT) stands out, with technological advances to deliver targeted treatments adapted to a tumor's anatomy on the day while minimizing incidental exposure to organs at risk, offering an unprecedented therapeutic advantage compared to X-ray-based IGRT delivery systems. This new technology changes the traditional workflow in radiation oncology and requires an evolution in team coordination to administer more precise treatments. Once implemented, it paves the way for newer indication for radiation therapy to safely deliver higher doses than ever before, with better preservation of healthy tissues to optimize patient outcomes. In this narrative review, we assess the technical aspects of the novel linear accelerators that can deliver MRgRT and summarize the available published experience to date, focusing on oncological results and future challenges.

Stereotactic body radiation therapy for kidney cancer. Where do we stand?

At present, surgery is still the gold standard for the local treatment of renal cancer. Nonetheless, in several clinical scenarios, stereotactic body radiation therapy (SBRT) also known as stereotactic ablative body radiotherapy (SABR) is emerging as a highly effective ablative technique in fragile patients and those with significant comorbidities, as well as in cases where percutaneous therapy (cryoablation or radiofrequency) is not viable. However, considering the intrinsic radioresistance of renal tumors, the optimal treatment schemes have not been established. In oligometastatic patients, it has been reported that the control of the oligometastases can be a potentially curable approach. Being a technique than can be administered exclusively or in combination with systemic therapy, treatment individualization based on patient characteristics is key. Another scenario under investigation is oligoprogression, where SBRT offers the possibility of delaying further lines of systemic therapy by eliminating subclones of resistant tumor with ablative doses, with the additional opportunity of stimulating the immune system (immunomodulatory role). In this review, we have conducted an analysis of recently published studies that test the role of this technique in different clinical scenarios of this disease. We have found promising results that make SBRT a potent therapeutic approach with low toxicity. We also comment on ongoing studies that will generate the necessary evidence needed for the implementation of this technique in our daily clinical practice.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Prognostic Factors in Locally Advanced Rectal Cancer.

INTRODUCTION: The standard therapy for locally advanced rectal cancer (LARC) is based on neoadjuvant chemoradiotherapy (nCRT) with fluoropyrimidines. There are different biomarkers used as prognostic factors in these tumors. Some studies advocate the use of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as prognostic factors in this clinical scenario. The aim of the study was to evaluate NLR and PLR as prognostic factors of disease-free survival (DFS) and overall survival (OS) and as predictive factors of pathologic complete response (pCR) using Ryan tumor regression scoring system on surgical specimens, in patients with locally advanced rectal adenocarcinoma who received nCRT and radical surgery. METHODS: We retrospectively evaluated patients with locally advanced rectal adenocarcinoma (T3-T4, N1-N3, M0 according to the TNM classification, AJCC 8th edition) who received nCRT based on fluoropyrimidines and radical surgery. Complete blood cell count before nCRT was obtained to calculate NLR and PLR. We made subgroups of patients according to NLR and PLR. We obtained the cut-off point for these ratios based on receiver operating characteristic analysis. We analyzed OS and DFS using the Kaplan-Meier method and Cox proportional hazard models. The relationships between NLR/PLR and pCR, along with other clinical-pathological characteristics, were evaluated by Pearson's χ2 or Fisher's exact test as appropriate. Multivariate analyses were performed using Cox proportional hazard regression models. RESULTS: Between February 2012 and February 2017, 100 consecutive patients were treated according to the reported schedules. Median age was 76 years (68-83). All patients received radiotherapy up to 50.4 Gy and 5-FU-based chemotherapy. 100% completed nCRT and surgery, 38% had elevated basal NLR (cut-off >1.95), and 50% had elevated basal PLR (cut-off >133). After a median follow-up of 72 months (55-88), a lower DFS was obtained in the high NLR subgroup (log-rank, Mantel-Cox 5.165, p = 0.023) and in the high PLR subgroup (log-rank, Mantel-Cox 13.971, p = 0.001). Multivariate analysis showed that PLR (p = 0.006) was a strong significant predictor of DFS. A lower OS was observed in the high NLR and PLR subgroup without significant differences (log-rank, Mantel-Cox 1.245, p = 0.265; 0.578, p = 0.447). No significant differences were obtained in any of the subgroup analysis regarding pCR rates. CONCLUSION: In light of our results, both NLR and PLR could be considered prognostic factors for DFS in patients with LARC that receive treatment with nCRT followed by surgery.

Immunotherapy in Advanced Prostate Cancer: Current Knowledge and Future Directions.

The advent of immunotherapy has revolutionized cancer treatment. Unfortunately, this has not been the case for metastatic castration-resistant prostate cancer (mCRPC), likely due to the heterogeneous and immune-suppressive microenvironment present in prostate cancer. The identification of molecular biomarkers that could predict response to immunotherapy represents one of the current challenges in this clinical scenario. The management of advanced castration-resistant prostate cancer is rapidly evolving and immunotherapy treatments, mostly consisting of immune checkpoint inhibitors combinations, BiTE® (bispecific T-cell engager) immune therapies, and chimeric antigen receptors (CAR) are in development with promising results. This review analyses the current evidence of immunotherapy treatments for mCRPC, evaluating past failures and promising approaches and discussing the directions for future research.

IJRadiation therapy for recurrent hydatid cyst of the pelvic bone: a case report.

BACKGROUND: Hydatid disease usually affects the liver, but can also extend to other locations, such as the bones. In these cases, complete resection of the bone is considered the only curative approach. However, this is rarely feasible, and patients are left with benzimidazoles as their only option. In this context, there is an evident need for alternative treatments that can improve results. We present the case of a patient with a treatment-refractory hydatid cyst of the bone, who successfully underwent radiotherapy (RT). CASE SUMMARY: A 64-year-old woman was diagnosed with a hydatid cyst of the bone in the sacroiliac joint that caused her sciatalgia and paresthesia. She underwent treatment with albendazole and surgery, and was treated with further doses of albendazole after relapsing six months later. After 2 years, she required a new resection, achieving a stable disease for 2 more years. At this point, she began to suffer from more intense pain (visual analogue scale 6/10). Given that further surgery was no longer feasible, she underwent radiotherapy (54 Gy in 27 fractions). No treatment-related toxicity was observed. At 1 month after radiotherapy, the pain had completely disappeared; 9 months later, the patient remains asymptomatic. The titer of anti-Echinococcus-granulosus antibodies and the absolute volume of eosinophils decreased after treatment with radiotherapy. The cyst remains radiologically stable. CONCLUSION: Although further studies are needed, radiotherapy seems to be effective for hydatid cysts that are refractory to other treatments.

Immunoradiotherapy as An Effective Therapeutic Strategy in Lung Cancer: From Palliative Care to Curative Intent.

Lung cancer is one of the main causes of cancer-related mortality worldwide. Over the years, different therapeutic modalities have been adopted depending on tumor stage and patient characteristics, such as surgery, radiotherapy (RT), and chemotherapy. Recently, with the development of immune-checkpoint inhibitors (ICI), the treatment of metastatic and locally advanced non-small cell lung cancer (NSCLC) has experienced a revolution that has resulted in a significant improvement in overall survival with an enhanced toxicity profile. Despite this paradigm shift, most patients present some kind of resistance to ICI. In this setting, current research is shifting towards the integration of multiple therapies, with RT and ICI being one of the most promising based on the potential immunostimulatory synergy of this combination. This review gives an overview of the evolution and current state of the combination of RT and ICI and provides evidence-based data that can improve patient selection. The combination in lung cancer is a safe therapeutic approach that improves local control and progression-free survival, and it has the potential to unleash abscopal responses. Additionally, this treatment strategy seems to be able to re-sensitize select patients that have reached a state of resistance to ICI, further enabling the continuation of systemic therapy.

Stereotactic ablative radiotherapy for oligometastatic breast cancer in elderly patients.

Breast cancer (BC) is the principal cause of cancer-related death in women. Metastatic patients are usually treated with a systemic therapy, but clinical results are limited. Oligometastatic subjects can benefit from high-precision radiotherapy techniques to potentially achieve a complete response. Currently, there is limited evidence of stereotactic ablative radiotherapy (SABR) treatments in elderly oligometastatic cancer patients. A review of the medical literature was performed in PubMed database to assess the current role of SABR in the treatment of breast oligometastases in elderly patients. SABR represents a feasible and safe therapeutic approach in oligometastatic elderly BC patients. Further studies are required to establish the optimum patient selection and treatment scheme.

Stereotactic Ablative Radiotherapy Combined with Immune Checkpoint Inhibitors Reboots the Immune Response Assisted by Immunotherapy in Metastatic Lung Cancer: A Systematic Review.

Background: Immune checkpoint inhibitors (ICI) have represented a revolution in the treatment of non-small-cell lung cancer (NSCLC). To improve these results, combined approaches are being tested. The addition of stereotactic ablative radiotherapy (SABR) to ICI seems promising. A systematic review was performed in order to assess the safety and efficacy of SABR-ICI combination. Material and Methods: MEDLINE databases from 2009 to March 3, 2019 were reviewed to obtain English language studies reporting clinical outcomes of the combination of ICI-SABR in NSCLC. 18 out of the 429 initial results fulfilled the inclusion criteria and were selected for review. Results: Eighteen articles, including six prospective studies, describing 1736 patients treated with an ICI-SABR combination fulfilled the selection criteria. The reported mean rates for local control and distant/abscopal response rates were 71% and 41%, respectively. Eleven studies reported progression-free survival and overall survival, with a mean of 4.6 and 12.4 months, respectively. Toxicity rates were consistent with the ones attributable to ICI treatment alone. Conclusions: The ICI-SABR combination has a good safety profile and achieves high rates of local control and greater chances of obtaining abscopal responses than SABR alone, with a relevant impact on PFS. More studies are needed to improve patient selection for an optimal benefit from this approach.