One of them is a relatively new method of radiotherapy, Stereotactic Body Radiation Therapy (SBRT), a method that has come to significantly change the data in radiotherapy and has already become an important ally in the fight against cancer – alone or in combination with other treatments.
Stereotaxy is a non-invasive, bloodless and patient-friendly, but radical treatment that is applied to various areas of the body. It consists in the administration of radiation with absolute accuracy in tumors of size ≤ 5-3 cm).
The hallmark of stereotactic body radiotherapy is the administration of a single therapeutic dose of radiation or a few fractionated high doses of radiation (up to 5), right at the site of the tumor with a sharp drop in dose around it. Administration of high doses of radiation causes damage to the vessels that supply the tumor, causing the apoptosis of cancer cells. Therefore, stereotactic radiotherapy is considered a tumor ablative effect.
Accuracy
Never before has radiotherapy been able to target a tumor with such precision. In fact, specific techniques, such as Image Guided Radiotherapy-IGRT (image-guided radiotherapy), Surface Guided Radiotherapy-SGRT and the use of patient immobilization systems, ensure maximum targeting accuracy and safety.
In areas of the body (such as organs) that can not be immobilized, the DIBH (Deep Ispiration Breath Hold) technique comes to offer significant help. With the help of special equipment, the patient can control his breathing during irradiation.
In this way, we not only confirm the accuracy of the body position and the repeatability of the treatment, but we can also control the movement of the tumor during the treatment. Thus, the radiation is delivered to the nearest millimeter, leaving the surrounding normal tissues intact.
Differences from conventional radiotherapy
The usual duration of SBRT includes 1-5 treatments over a period of up to two weeks and not on a daily basis. This is a significant advantage of SBRT over conventional external beam radiotherapy, in which the dose is given daily for several weeks.
With SBRT, the treatment time is significantly reduced, as well as the patient’s movements, while it is possible for the patient to return more quickly to additional therapeutic treatments (immunotherapy, chemotherapy).
The administration of much higher doses of radiation in a much shorter period of time is comparatively more effective in tumors with increased radiation resistance (sarcoma, kidney cancer, melanoma).
Delivering a high dose of radiation directly to the tumor also improves cure rates, in a way that to date could not be achieved with conventional radiotherapy.
The results of SBRT are in many cases comparable to those of resection surgeries.
Indications
Modern studies have shown the benefit of stereotactic radiotherapy in the treatment of early lung and prostate cancer (early-intermediate stage), gastrointestinal cancers (pancreas, liver), tumors in the spine, but also in hepatic metastases. in the context of oligometastatic disease.
Current studies show significant benefits in early breast and kidney cancer as well.
Advantages
In summary, SBRT:
• It is painless for the patient and non-invasive.
• It is extremely short. It can be completed in up to 5 treatments of 15 minutes, compared to conventional radiotherapy regimens, which last 6-7 weeks and include daily treatments.
• Immediately improves clinical symptoms (eg pain), allows good local control of the disease, reducing the risk of a subsequent recurrence and can under certain conditions offer a complete cure.
• The patient during the treatment maintains the daily rhythms and after the end of the treatment returns immediately to his daily life, personal, social and professional. During and after SBRT, the patient maintains a good quality of life.
• Due to the small radiation field, radiation exposure of the surrounding healthy tissues is avoided.
Conditions
The application of stereotactic radiotherapy is very demanding and requires specialization and experience from the Radiotherapist – Oncologist, but also from all the scientific staff (radiophysicists, technologists) who will undertake the case. A highly technologically advanced radiation delivery system is also required. That is why it should be done in Highly Specialized Centers.
The Center for Radiation Oncology (KAO) of HYGEIA, in its more than 25 years of operation is the most modern and fully equipped center in Greece and one of the best in Europe. The Center has, apart from the last four (4) Generation Linear Accelerators and the state-of-the-art High Dose Brachytherapy unit, the only γ-Knife radiosurgical machine in Greece.
Writes:
George Kritselis Radiotherapist – Oncologist
Associate of the HYGEIA Radiation Oncology Center
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