The era of radiation in treatment of lung cancer

THE TREATMENT METHODS FOR LUNG CANCER, ONE OF THE MOST COMMON CANCER TYPES, CONTINUE TO DEVELOP FURTHER WITH EACH PASSING DAY. THE DEVELOPMENTS IN THE FIELD OF RADIATION ONCOLOGY ARE PARTICULARLY HELPFUL IN ACHIEVEMENT OF SUCCESSFUL RESULTS IN ELIMINATION OF TUMORS AND EXTENSION OF SURVIVAL TIMES.

Throughout the world, lung cancer is the first disease to come to the mind when the word “cancer” is mentioned. In this disease, which ranks the highest in terms of mortality rates, early diagnosis and effective treatment has critical importance. The treatment can involve surgery, chemotherapy and radiotherapy. This disease is divided into two subtypes: small cell lung cancer and non-small cell cancer.

Since there is a possibility of spreading and metastasizing to distant organs in small cell lung cancer, systemic treatments are more prominent in handling of this subtype. Radiotherapy and surgery can only be used when the disease is limited inside the body. Non-small cell lung cancer patients, who form a larger group than that of small cell lung cancer patients, require treatment according to the stage of the disease. Professor Mehmet Ufuk Abacıoğlu, a radiation oncologist at Acıbadem Altunizade Hospital, states that radiotherapy is particularly beneficial for early-stage cases, in which patients have lung tumors that are not too large and that have not spread to the mediastinal lymph nodes between the two lungs or other distant areas.

“Surgery and stereotactic radiotherapy are applied with similar aims in mind. However, the decision on the choice of treatment method for a specific patient should be made with a multidisciplinary approach.”

NEW APPROACHES IN RADIOTHERAPY

Each passing day brings promising developments in treatment of cancer. The latest innovation in the field of radiation oncology enables application of higher doses with more effect and less side effects in the early stage! Stating that there are two treatment options for a patient with a lung tumor of 3 cm in Stage 1 or 2 without the presence of metastasis, Professor Abacıoğlu shares with us the following information: “In the said condition, the lung lobe with the tumor is removed or, if the patient is not suitable for surgery due to dysfunction in lungs, other disorders that accompany cancer or anesthesia risk, a radiation therapy of three to eight sessions is applied. At the end of this therapy, the possibility of completely eliminating the tumor, preventing tumor growth, or shrinking the tumor is over 90%. This means that the results radiation therapy yields are very good, almost as good as those of surgery, which is the golden standard.”

SURGERY IS NOT THE ONLY SOLUTION!

Stating that the new radiotherapy method, which is used in cases where surgery is not possible, can also be an option for patients suitable for surgical treatment when the research on the subject receives approval in the upcoming days, Professor Abacıoğlu describes the method referred to as stereotactic body radiotherapy as follows: “Application of radiotherapy with the existing technologies required for large areas to be subjected to radiation. Since this made effects on the surrounding tissues unavoidable, the dose of radiation to be applied had to be limited. In any case, when applying radiotherapy for lung tumors, the organ that is under the greatest risk is the lung itself due to its high sensitivity to radiation. Surrounding organs and structures such as the esophagus, heart, arteries, chest wall, ribs and the spinal cord also require for the dose to be limited. With stereotactic body radiotherapy, however, it is possible to apply high doses of radiation on a single, confined area while protecting other areas.

SIDE EFFECTS ARE REDUCED

In the past, patients experienced problems such as shortness of breath, dry cough and fever in the early or late period due to the tissue damage in the lung after radiotherapy on the organ. The new method minimizes these side effects. For instance, swallowing difficulties which followed radiotherapy on tumors close to the esophagus have become much less frequent these days. The method is very effective in protection of the esophagus. Furthermore, the image-guided radiotherapy method involves production of images while the patient is on the table and ensures radiation with better-than-millimetric precision. Professor Abacıoğlu says, “The application speed in new technology devices is so fast that even the doses that are considered to be very high can be applied in a few minutes and the duration a patient spends on the therapy table is reduced”, and continues as follows: “This also reduces the possibility of movement during the application and ensures for the treatment to be performed as perfectly as possible. The treatments in the past, which took 15 to 60 minutes, images had to be produced over and over again due to the difficulties experienced in keeping patients lying on their back without the slightest movement. Now, however, the treatment is over in 10 to 15 minutes, including the time in which the patient enters and leaves the room”.

HEALTHY TISSUES CAN BE PRESERVED DESPITE HIGH DOSES

In periods following the early stage, the standard treatment involves application of chemotherapy and radiotherapy together. Stating that intensity-modulated radiation therapy is used in such cases, Professor Abacıoğlu says, “The target area does not consist of only the tumor in the lung but also includes the other lymph nodes. When the purpose is to apply radiation on both the lymph nodes and the tumor at the same time while protecting the surrounding tissues, intensity-modulated radiation therapy comes to the rescue. During the treatment, the device rotates 360 or 180 degrees around the patient and radiation beams are applied with use of constantly moving, very thin leaves. These moving leaves allow beams to reach the patient when they detect the tumor and block the beams when they detect normal tissue. Therefore, despite application of higher doses, it is possible to preserve healthy tissues. The most important advantage lies in the fact that since side effects are reduced, radiotherapy and chemotherapy can be applied together without need for intervals.

DIFFERENT TUMORS THAT METASTASIZE ARE ALSO TARGETED

The stereotactic body radiation therapy can be used for lung metastasis cases as well. In the past, presence of metastases that resisted systemic treatment required surgical removal of tumors first. Sometimes the patients underwent many surgeries or even had a part of their lungs removed. Stating that it is now possible to achieve success by applying radiation only on the necessary areas and avoiding damage to the lungs, Professor Mehmet Ufuk Abacıoğlu says, “Even in case of a bone sarcoma considered to be radiation-resistant such as an osteosarcoma, similarly successful results can be achieved through application of high radiation doses on a confined area. Many of our patients apply to us when their metastases have progressed. This method makes it possible for metastases to be taken under control via application of radiation on only the affected areas. However, it should be noted that the method yields positive results when it is used for metastases of limited number and size which are not too close to critical structures”.