Lung Cancer - How Can Radio Therapy Help?

As much as you want to avoid, there are things you have no control over. Lung cancer (Bronchogenic Carcinomas) is one such nemesis that can throw life in shambles. The malignant tumour that originates in the lungs slowly spreads onto the other distinct and vital organs as well. Thought to be mostly affecting men who are chain smokers and into severe tobacco consumption, incidences of lung cancer in women are rising at an alarming rate over the past few years. Non-smokers may also be susceptible (to a lesser extent though) to lung cancer.

Lung cancer can be either

• Non-small cell lung cancers: The NSCLC, accounting for ~85% of lung cancer is one of the most common types of lung cancer affecting people, NSCLC may further be divided into
• Adenocarcinoma: This type of NSCLC originates mostly in the peripheral regions of the lungs and may affect (spread) the lymph nodes. Non-smokers and women are mostly at the receiving end (other than the chain smokers).
• Squamous Cell Carcinoma: Also known as Epidermoid Carcinoma, often affects men, epidermoid carcinoma may originate in the tissues that line the bronchial tubes. The lymph nodes are often affected by Epidermoid Carcinoma.
• Large-cell Undifferentiated Carcinoma: The point of origin of large-cell undifferentiated carcinoma is the surface of the lungs. They have a higher probability of spreading to the lymph nodes.
• Bronchioalveolar Carcinoma: Though rare, bronchioalveolar carcinoma originates close to the air sacs.
• Small Cell Lung Cancer (SCLC, accounting for ~25% of the lung cancer): As the name suggests, SCLC is marked by the rapid proliferation of small cells into large malignant tumours. SCLC can move throughout the body (affecting vital organs).

Radiotherapy to treat Lung cancer:
Radiotherapy plays a pivotal role in the treatment of lung cancer. The radiation therapy is mainly of two types

• External beam radiation therapy (EBRT)
• Internal radiation therapy (Brachytherapy)

In external beam radiation therapy, high-energy rays are focused on the cancer cells (thereby resulting in the apoptosis of the cancer cells) externally, from outside the body. EBRT is particularly helpful in the case of Non-small cell lung cancers.

The EBRT may be of the following types

• 3D-CRT (Three-dimensional conformal radiation therapy): An advanced radiation therapy, 3D-CRT accurately marks the position of the cancer cells (using advanced computers). The treatment ensures minimum damage to the other healthy cells and tissues (energy rays are directed at the affected cells from different positions).
• SBRT (Stereotactic body radiation therapy): This is a radiation therapy used in the treatment of NSCLC when it is at a nascent stage.
• IMRT (Intensity-modulated radiation therapy): As the name suggests, in IMRT, the intensity of the radiation reaching the normal tissues and cells can be modulated. Like 3D-CRT, the radiation in IMRT is directed from different angles (for maximum results).
• Internal radiation therapy (Brachytherapy): This type of radiation therapy is generally used to deal with lung cancers that tend to block the airways. In this therapy, the radiation process is carried out through a narrow tube, thereby, shrinking and collapsing the tumour.

The effect, dosage, and duration of radiation therapy depend on the stage and severity of the condition. In some cases, radiation therapy may be given together with chemotherapy. As lung cancer is a systemic disease, so chemotherapy plays an important role, for locally advanced cancer chemoradiotherapy is an option or in sequence, for metastatic disease biological therapy and immunotherapy play a key role these days.