What is the treatment for radiation-induced organizing pneumonia in a patient undergoing ongoing chemotherapy?

From the Guidelines

Treatment of radiation-induced organizing pneumonia (RIOP) in patients undergoing chemotherapy typically involves corticosteroids while continuing cancer treatment if possible, with the standard approach being oral prednisone at 0.5-1 mg/kg/day for 1-2 weeks, followed by a slow taper over 2-3 months, as recommended by recent guidelines 1. The use of corticosteroids is supported by evidence from studies on radiation pneumonitis, which suggests that anti-inflammatory therapy with corticosteroids is effective in reducing symptoms and improving outcomes 1. Key considerations in the management of RIOP include:

• The use of oral prednisone at a dose of 0.5-1 mg/kg/day, typically 40-60 mg daily, for 1-2 weeks, followed by a slow taper over 2-3 months 1
• The consideration of inhaled corticosteroids, such as budesonide 800 mcg twice daily, for patients who cannot tolerate systemic steroids due to chemotherapy complications 1
• The importance of supportive care, including oxygen therapy if hypoxemia is present, and prophylaxis against steroid-related complications, such as PCP prophylaxis with trimethoprim-sulfamethoxazole and bone protection with calcium/vitamin D supplements
• The need to pause radiation therapy to the affected lung area until improvement occurs, while chemotherapy can usually continue during RIOP treatment unless severe respiratory compromise exists
• The importance of close monitoring with pulmonary function tests and imaging during treatment, as recommended by recent studies 1.

From the Research

Radiation-Induced Organizing Pneumonia Treatment

• Radiation-induced organizing pneumonia (RIOP) is an inflammatory lung disease that can occur after irradiation, and its management should be symptom-oriented 2.
• Corticosteroids are effective in treating RIOP, but they can lead to frequent relapses, and their use should be limited to severe symptoms 2, 3, 4.
• The duration of steroid therapy can be long due to frequent relapses, and tapering the dose of corticosteroids may lead to relapse 4.
• Steroid treatment has been shown to increase the recurrence of RIOP, and the median duration of RIOP was significantly longer in patients who received steroid therapy compared to those who did not 5.

Ongoing Chemotherapy

• There is no direct evidence in the provided studies on the treatment of RIOP in patients undergoing ongoing chemotherapy.
• However, it is mentioned that the use of corticosteroids should be limited to severe symptoms from the perspective of cancer treatment, suggesting that chemotherapy may be a consideration in the management of RIOP 2.
• One study reported a case where a patient was on prednisone and azathioprine throughout the course of radiation therapy, but still developed radiation-induced lung injury, including bronchiolitis obliterans organizing pneumonia (BOOP) 6.

Treatment Options

• Corticosteroids, such as prednisolone and methylprednisolone, are commonly used to treat RIOP, and they can lead to rapid clinical and radiological improvement 3, 6, 4.
• The dose of corticosteroids should be slowly tapered over a period of ≥6 months to minimize the risk of relapse 4.
• Non-steroid treatment options may be considered, as they have been shown to result in fewer relapses and a shorter duration of RIOP compared to steroid therapy 5.