Bilateral radiation recall pneumonitis during immunotherapy for an advanced renal cell carcinoma: A challenging case enhances the need for a multidisciplinary approach

Radiation recall pneumonitis from immune checkpoint inhibitors after extra pulmonary radiation

Radiation recall is an unpredictable, poorly understood inflammatory reaction within the confines of previously irradiated tissue that occurs following exposure to a systemic agent. In this article, we will focus on a subcategory of radiation recall, called radiation recall pneumonitis (RRP), precipitated by immune checkpoint inhibitors (ICI). Historically, RRP can develop weeks to years after radiation treatment to the lung, most commonly after receiving certain chemotherapeutic agents, but more recently has been recognized in association with immunotherapy agents (ICIs). Up until now, RRP following exposure to ICIs has been described in patients who have received radiation to the lung itself. Here we present three cases of RRP in patients who received radiation to areas adjacent to the lung parenchyma, and developed pulmonary infiltrates in an area adjacent to the radiation field while on ICI therapy. Since ICI induced RRP is treatable and steroid sensitive, early recognition and treatment are important.

Safety and efficacy of radiotherapy/chemoradiotherapy combined with immune checkpoint inhibitors for non-small cell lung cancer: A systematic review and meta-analysis

Background

It is now widely accepted that radiotherapy (RT) can provoke a systemic immune response, which gives a strong rationale for the combination of RT and immune checkpoint inhibitors (ICIs). However, RT is a double-edged sword that not only enhances systemic antitumor immune response, but also promotes immunosuppression to some extent. Nevertheless, many aspects regarding the efficacy and safety of this combination therapy remain unknown. Therefore, a systematic review and meta-analysis was performed in order to assess the safety and efficacy of RT/chemoradiotherapy (CRT) and ICI combination therapy for non-small cell lung cancer (NSCLC) patients.

Methods

PubMed and several other databases were searched (according to specific criteria) to find relevant studies published prior to the 28th of February 2022.

Results

3,652 articles were identified for screening and 25 trials containing 1,645 NSCLC patients were identified. For stage II-III NSCLC, the one- and two-year overall survival (OS) was 83.25% (95% confidence interval (CI): 79.42%-86.75%) and 66.16% (95% CI: 62.3%-69.92%), respectively. For stage IV NSCLC, the one- and two-year OS was 50% and 25%. In our study, the pooled rate of grade 3-5 adverse events (AEs) and grade 5 AEs was 30.18% (95% CI: 10.04%-50.33%, I2: 96.7%) and 2.03% (95% CI: 0.03%-4.04%, I2: 36.8%), respectively. Fatigue (50.97%), dyspnea (46.06%), dysphagia (10%-82.5%), leucopenia (47.6%), anaemia (5%-47.6%), cough (40.09%), esophagitis (38.51%), fever (32.5%-38.1%), neutropenia (12.5%-38.1%), alopecia (35%), nausea (30.51%) and pneumonitis (28.53%) were the most common adverse events for the combined treatment. The incidence of cardiotoxicity (0%-5.00%) was low, but it was associated with a high mortality rate (0%-2.56%). Furthermore, the incidence of pneumonitis was 28.53% (95% CI: 19.22%-38.88%, I2: 92.00%), grade ≥ 3 pneumonitis was 5.82% (95% CI: 3.75%-8.32%, I2: 57.90%) and grade 5 was 0%-4.76%.

Conclusion

This study suggests that the addition of ICIs to RT/CRT for NSCLC patients may be both safe and feasible. We also summarize details of different RT combinations with ICIs to treat NSCLC. These findings may help guide the design of future trials, the testing of concurrent or sequential combinations for ICIs and RT/CRT could be particularly useful to guide the treatment of NSCLC patients.

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

Radiation recall pneumonitis triggered by an immune checkpoint inhibitor following re-irradiation in a lung cancer patient: a case report

Background

Radiation recall pneumonitis (RRP) is unpredictable but associated with severe radiation damage in previously irradiated fields. Chemotherapy and targeted drugs have been reported to contribute to RRP. Here we report a case of a patient with non-small cell lung cancer (NSCLC) who developed RRP following administration of immune checkpoint inhibitor (ICI) 18 months after the end of re-irradiation.

Case presentation

A 69-year-old man received adjuvant chemoradiotherapy post-operatively. He underwent thoracic re-irradiation for oligometastatic NSCLC. On second recurrence, pembrolizumab combined with nab-paclitaxel were administered. After six months, he developed symptoms of persistent cough and dyspnea, with consistent pneumonitis on CT images. The clinical time frame and significant radiographic evidence raised suspicion for RRP. Symptoms resolved after steroids.

Conclusions

RRP is a rare occurrence. Patients undergoing immunotherapy after prior irradiation may be at increased risk of this rare radiation pneumonitis.