From the Guidelines
Radiotherapy is a crucial component in the treatment of small cell lung cancer (SCLC), with specific indications based on disease stage and patient factors, and concurrent chemoradiotherapy is the standard of care for limited-stage SCLC, as recommended by the most recent guidelines 1.
Indications for Radiotherapy in SCLC
The indications for radiotherapy in SCLC include:
- Limited-stage SCLC, where concurrent chemoradiotherapy is the standard of care, typically delivering 45 Gy in 30 twice-daily fractions or 60-70 Gy in once-daily fractions, starting with the first or second cycle of chemotherapy 1
- Extensive-stage SCLC, where consolidative thoracic radiotherapy (30 Gy in 10 fractions) is indicated for patients who respond to systemic therapy, as it reduces local recurrence and modestly improves survival 1
- Prophylactic cranial irradiation (PCI) at 25 Gy in 10 fractions is recommended for patients with both limited and extensive disease who achieve a good response to initial therapy, as it significantly reduces brain metastases risk and improves overall survival 1
Timing and Dose of Radiotherapy
The optimal timing of concurrent radiotherapy has been studied extensively, and it is recommended to start chest radiotherapy within 30 days after the beginning of chemotherapy 1. The dose of radiotherapy also varies, with twice-daily radiotherapy (1.5 Gy twice-daily, 30 fractions) showing superior 5-year overall survival compared to once-daily radiotherapy (1.8 Gy, 25 fractions) 1.
Chemotherapy Regimen
The chemotherapy regimen used in conjunction with radiotherapy is typically cisplatin and etoposide, with standard dosing being used, that is, cisplatin 60-80 mg/m2 once on day 1 and etoposide 100-120 mg/m2 once on days 1,2, and 3 of an every 3-week cycle 1.
From the Research
Indications of Radiotherapy in Lung Small Cell Lung Cancer
- Radiotherapy (RT) is a crucial component in the management of small cell lung cancer (SCLC), particularly in limited-stage disease (LS-SCLC) where it is used in conjunction with chemotherapy 2, 3, 4.
- In LS-SCLC, the standard initial therapy is concurrent chemoradiotherapy (CRT), typically with an etoposide and platinum-based regimen, and hyperfractionated twice daily (BID) RT or conventional daily (QD) RT 2.
- Prophylactic cranial irradiation (PCI) is indicated in LS-SCLC patients who have experienced a good response to CRT, as it reduces the risk of brain metastases and improves overall survival 2, 3, 4, 5.
- In extensive-stage SCLC (ES-SCLC), radiotherapy has a role in palliating chest symptoms, and PCI can reduce the risk of brain metastases and improve overall survival in responding patients 2, 3, 4.
- The optimal dose and schedule of thoracic RT, as well as the role of thoracic RT in ES-SCLC, are still being investigated in ongoing clinical trials 2, 4, 5.
- Technological advances have allowed for safer delivery of radiotherapy with reduced toxicities, making it an essential component in the multimodality management of SCLC 5.
- Discussion at multidisciplinary team meetings is important to ensure that radiotherapy is considered and offered to appropriate patients 5.
Specific Radiotherapy Regimens
- Hyperfractionated accelerated radiation therapy (HART) with cisplatin/etoposide chemotherapy has been shown to be feasible and effective in LS-SCLC patients, with a median survival time of 24 months 6.
- Twice daily (BID) RT remains the standard of care in LS-SCLC, although conventional daily (QD) RT is now a viable alternative supported by randomized evidence 2.
- Whole brain radiotherapy is well established for the treatment of brain metastases, but evidence is accumulating for the use of stereotactic radiosurgery 5.