The Role of Radiotherapy
According to estimates by the Global Cancer Observatory, the number of cancer patients is growing worldwide: more than 18 million people were diagnosed with various types of malignant tumors in 2018. But in parallel with the increase in the number of cases, new drugs are emerging, the results are improving, the experience of doctors is steadily improving, and clinical trials come with clear evidence of the effectiveness of oncology therapies. Among these, radiotherapy is one of the most dynamic areas in oncology, with multiple benefits for patients. Radiation experts are an important part of multidisciplinary teams that successfully treat cancers, even in advanced stages, with metastases. One of the best specialists in Turkiye and the world in radiotherapy is Prof. Dr. Ufuk Abacioglu. Over the past 25 years, the top physician has treated thousands of patients and today applies the latest radiotherapy technologies in ACIBADEM hospitals. Prof. Dr. Ufuk Abacioglu further explains the role of radiotherapy in treating cancers and how modern technologies succeed in increasing the life expectancy of cancer patients.
What are the main objectives of radiotherapy in oncology treatment?
Prof. Dr. Ufuk Abacioglu: Radiotherapy and surgery are local treatments, unlike chemotherapy, targeted therapies and immunotherapy that are systemic treatments. Many people think that if they are diagnosed with cancer, they will do chemotherapy, which is not the case in all patients. Most of the benefits in treating cancers have local therapies. Of the 100 patients diagnosed with cancer, 20 percent will be treated only by surgery, and 15 percent will be treated only by radiotherapy. Chemotherapy will only be given in 2-3 percent of cases. Combining these methods will increase the chances of successfully treating a cancer. In addition, with a 10 percent technology upgrade, the radiotherapy treatment success rate improves by 15-16.5 percent. Imagine what good outcomes we can achieve with only a few improvements in local therapies in the treatment of cancer at the population level.
What is the effect of radiotherapy on tumors and how does disease condition condition the success of the therapy?
Prof. Dr. Ufuk Abacioglu: Many people ask us what radiotherapy does: stops tumor development, has any palliative effect? The answer depends on how radiotherapy and irradiation doses we give to patients. If we give an ablative dose, in a safe fraction, in radiosurgery for example, then we actually remove the tumor. This means total tumor mass eradication without leaving any tumor cells on the spot. This is the purpose of radical radiotherapy. Let’s take the example of a lung cancer patient in Stage 1 with peripheral lung localization with a 2 cm. tumor, subject to an ablative radiotherapy in 3 or 5 fractions. In more than 90 percent of cases, treatment will be a success, meaning no residual cells will remain. After post-treatment imaging investigations, signs of irradiation at the tumor site may be observed, but they will not show functional changes, side effects, or other symptoms. The effect is similar to surgery, but with less risk and cost than surgery. In case of lung cancer surgery, patients may experience postoperative pain for 6 months due to chest incisions. Even in minimally invasive surgery, there are risks before and after surgery. Before we apply a treatment, we evaluate each case and decide which of the patients will be better with surgery, and whom we can apply radiotherapy to and whom we will apply a combination of oncological therapies to.
What types of cancer benefit most from radiotherapy?
Prof. Dr. Ufuk Abacioglu: At present, radiotherapy can be applied in a wide variety of cancers. In almost any type of cancer, radiotherapy is recommended, but it depends on the stage and the condition of the patient. In our department, we have many patients with breast cancer who do radiotherapy after surgery. We also have many lung cancer patients, these two types of cancer being the most common. These patients are treated for primary tumors, but also for metastases. In medical practice, we have many patients with brain tumors that we treat by stereotactic radiosurgery. We apply therapy in one fraction and we treat areas affected by metastases. We also treat primary brain tumors with radiotherapy.
What is the radiotherapist’s role in the cancer treatment team?
Prof. Dr. Ufuk Abacioglu: Radiotherapists are part of the multidisciplinary oncology team and each physician has his role. There are three major branches: surgery, oncology radiotherapy and medical oncology, but besides these, there is the diagnostic group, radiology, nuclear medicine, the medical and clinical research group. The team also includes physicists, technicians, we all work together in oncology teams.
Do you apply radiotherapy before surgery?
Prof. Dr. Ufuk Abacioglu: Yes. For example, it is recommended in rectal tumors: we are talking about a standard treatment that has been applied fopr long. Studies over the past 20 years have shown that if we apply radiotherapy to rectal cancer before surgery, treatment outcomes are better than with post-operative radiotherapy. So, for patients with localized advanced rectal cancer, we apply radiotherapy combined with chemotherapy before surgery, then wait for a while, thepatient is operated, and then, if necessary, is given neoadjuvant chemotherapy. And if we have some patients where the cancer advances no more, 5 radiotherapy fractions can be applied and then the patients can be operated within a few days.
How do you subsequently monitor the outcome of radiotherapy? What are the imaging techniques you use?
Prof. Dr. Ufuk Abacioglu: Depending on location and type of cancer, we have various imaging options: CT, PET-CT, magnetic resonance. The first follow-up evaluation is 3 months after the end of the therapy. If the patient was diagnosed with the help of PET-CT technology, we expect 3 months to evaluate the metabolic response. But there are tumors that respond later to treatment, and we can wait six months or even a year. For example, benign tumors occurring at the cerebral level respond later. Of course, patients are carefully monitored, but the results may appear later. Generally, patients with cancers are evaluated periodically, 3 months, 2 years, then 6 months, up to 5 years after treatment, and then annually, 5 years after the end of therapy. Patient health monitoring is a lasting one, perhaps for the whole of life.
Do new technologies allow you to shorten the radiotherapy period?
Prof. Dr. Ufuk Abacioglu: The therapy period may be shorter for many patients. Take the example of prostate cancer. In the case of a localized cancer, radiotherapy lasts for 8 weeks. So, the patient came for two months for 40 treatment fractions. Today, in some patients, we can apply the treatment in 5 fractions, which implies a radically beneficial change for the patient. The patient only comes for two weeks, the toxicity is very low, and the results are similar. There are studies done over the past 5 years that compared the results of two-month treatments with the shortest, five-stage treatments. And this research continues to observe what the long-term results are. In some patients, the number of fractions and the treatment period may be reduced. I think that in the future there will be more and more patients treated with a smaller number of fractions.
What are the most successful cases you have had, if you are considering the stage of the disease, the size of the tumor? And how do you define success?
Prof. Dr. Ufuk Abacioglu: Long-term survival is the primary focus in oncology. Therefore, we look first at this. And then we evaluate the effectiveness of local disease control through radiotherapy. But the quality of life and other aspects such as neurocognitive impairment are other things that we have to take into account. For example, we can apply a treatment that will prevent new metastases, but that will not prolong life and affect neurocognitive function. Under these circumstances, we should not apply the treatment. We’ve just defined whole brain irradiation for patients with brain metastases. In the past, we applied full brain irradiation to these patients. Today, we only irradiate metastasis in most cases. As for the best results, surely these are recorded for small tumors. Let me give you an example of a larynx cancer at the onset. We can treat these patients successfully in 95 percent of cases, and the disease does not recur. Or we can successfully radiate nasopharyngeal cancer, even in situations where it is spread out. There are many localizations where we have good results.
The success of radiotherapy can be influenced by the presence of diseases such as diabetes or cardiovascular disease?
Prof. Dr. Ufuk Abacioglu: Of course, the comorbidities – as we call them, the diseases that make patients suffer, in addition to cancer, can restrict our treatments and even prevent us from planning radiotherapy in some cases. Some conditions may even get worse if your body is undergoing radiotherapy. Nowadays, we see more and more cases of cancer due to the increase in life expectancy, one of the risk factors for malignancies being the advanced age. And these elderly patients still have at least 2-3 other diseases besides cancer. In addition, obesity is common and increases the risk of diabetes, hypertension and cardiovascular problems. And these patients’ diseases can prevent us from applying oncology therapies. So, we always have to take into account the patient’s affections. Unfortunately, we can not always apply oncology treatment due to associated diseases that greatly reduce the chances of success of oncology therapies.
What can you do about the side effects of radiotherapy, such as necrosis? Are they still present despite the advanced technology?
Prof. Dr. Ufuk Abacioglu: The risk of adverse effects is much lower than in the past, but it exists. That’s why we need to find the right time to apply radiotherapy. If a patient has a tumor and already has necrosis or risk of necrosis, we should not reduce the radiation dose because the necrosis is already there. Necrosis means a tissue that does not oxygenate well, which is more resistant to radiotherapy, and then higher doses should be applied to these situations. If we do not apply radiotherapy, there is a risk of death due to the progression of the disease. I have cases of necrosis, fistula or other complications, but at the beginning of treatment, I explain to patients that they have a high risk of death due to illness without treatment. And then they accept radiotherapy knowingly and willingly. But compared to the past, the risk of side effects is lower.
Is Turkiye currently one of the most powerful countries in the world in treating cancer?
Prof. Dr. Ufuk Abacioglu: We are in a good spot, we have developed a lot over the last 20 years, we have performant hospitals, radiotherapy departments, we have the latest technologies and we adapt quickly to these new technologies. It is important to have the technology, but it is even more important to know how to use it and improve the treatment given to patients. And we are trying to do all these things in Turkiye. In addition, we collaborate with doctors around the world and radiotherapy researchers.
