RADIATION THERAPY
Radiation therapy in lung cancer treatment plan
Radiation therapy can be part of lung cancer treatment at any stage, both in non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). It can be used alone or with other treatments.
In non- small cell lung cancer (NSCLC)
Usually, radiation therapy for NSCLC means receiving treatment five days a week for five to seven weeks. But the exact plan can change depending on factors like the type of radiation therapy, the stage and location of the cancer, and the goals of treatment.
The following table shows how SBRT can be used to treat NSCLC based on the location and size of the tumor.
| Total Dose | Total # of Fractions | Size and Location of Lung Tumor |
| 25-34 Gy | 1 | Peripheral, small (<2 cm) tumors, especially >1 cm from chest wall |
| 45-60 Gy | 3 | Peripheral tumors and >1 cm from chest wall |
| 48-50 Gy | 4 | Central or peripheral tumors <4 -5 cm, especially <1 cm from chest wall |
| 50-55 Gy | 5 | Central or peripheral tumors, especially <1 cm from chest wall |
| 60-70 Gy | 8-10 | Central tumors |
In early stage NSCLC ( stages I and IIA with no spread to lymph nodes)
Stereotactic body radiotherapy (SBRT) is often suggested for individuals diagnosed at an early stage (stages I and IIA without lymph node metastases) who either cannot undergo surgery or opt not to. Nevertheless, alternative forms of external beam radiotherapy (EBRT) may also be prescribed. SBRT becomes a consideration for patients facing a high surgical risk, which could be attributed to factors like advanced age or poor lung function. Following surgery, EBRT is advised if margins of the resected cancer indicate the presence of remaining cancer cells.
In locally advanced NSCLC (stages II and III)
For stages II and III lung cancer, radiation therapy is typically combined with concurrent chemotherapy, meaning both treatments are given simultaneously. Surgery may also be considered as an alternative, and often, a combination of surgery and radiation therapy is recommended as part of the treatment plan. However, in cases where the patient cannot endure the potential side effects of receiving radiation and chemotherapy together, we may opt to administer chemotherapy before radiation therapy or use radiation therapy alone.
In advanced/metastatic NSCLC (stage IV)
For stage IV non-small cell lung cancer (NSCLC) with widespread metastases, radiotherapy (external beam radiation therapy (EBRT) and brachytherapy) can help with lung cancer symptoms, including pain or airway obstruction.
Stereotactic body radiation therapy SBRT may be used for oligometastases—when cancer has spread to limited areas.
Patients with brain metastases may undergo stereotactic radiosurgery (SRS), targeting specific metastatic sites. Another option is whole-brain radiation, delivering radiation to the entire brain. Although the comparative advantages of these techniques remain unclear, SRS administration tends to result in fewer side effects.
In certain cases, targeted therapies may be used to treat brain metastases without the need for radiation.
In small cell lung cancer (SCLC)
In limited- stage small cell lung cancer (LS - SCLC)
Patients with limited-stage small cell lung cancer often receive external beam radiotherapy (EBRT) along with chemotherapy – either concurrently or shortly before radiotherapy begins – to completely eliminate the tumor and achieve a long-term cure. This treatment usually involves daily radiation therapy therapy sessions for 6 to 7 weeks or twice-daily sessions for 3 weeks. Both schedules appear to have similar effectiveness in controlling tumors in the long term, with the once-daily option being more convenient. A European study showed that the two schedules have similar side effects and effectiveness.
Patients who respond well to initial treatment may also receive preventive radiation to the brain to avoid brain metastases.
In extensive- stage small cell lung cancer (ES - SCLC)
In patients with extensive-stage small cell lung cancer (ES-SCLC), external beam radiotherapy (EBRT) cannot entirely eliminate all cancer sites. However, it can be given after chemotherapy to better manage disease control in areas expected to recur. Additionally, it may be used to treat the entire brain to lower the chance of brain metastases and related neurological complications. EBRT is also used to relieve symptoms like pain, breathing difficulties, or bleeding that chemotherapy alone cannot alleviate.
