Teletherapy treatment techniques

Here you can know about the teletherapy techniques which is used in radiation therapy. It can also help you to prepare notes on them. You can download it in your PC or laptop to see the gif, it will clear the concept better.

1. RT Subhankar Kar RT Sanu Majumder T eletherapy treatment Techniques

2. Contents Radiotherapy Teletherapy Teletherapy techniques 2DCRT 3DCRT IMRT IGRT VMAT SBRT SRS

3. Radiotherapy Radiation therapy or Radiotherapy is a type of cancer treatment that uses high ionizing radiation doses to kill the cancer cells and shrink tumours. Radiation therapy can be delivered by two types of processes  Brachytherapy T eletherapy

4. Teletherapy Teletherapy is the production of an external beam of gamma rays for the treatment cancer patients at a distance from the radioactive source. Radioactive sources that have been used for teletherapy are Co–60, Ir–192, Cs–137 etc. Teletherapy treatment is useful for the treatment of cancers of head and neck area, ca–breast, ca–lung etc.

5. Teletherapy Techniques Nowadays different types of teletherapy treatment techniques have been used in radiotherapy; such as  2DCRT 3DCRT IMRT IGRT VMAT SBRT SRS

6. 2DCRT Two dimensional conventional radiation therapy (2DCRT) refers to the old techniques of radiation therapy where treatments would be planned by defining a limited number of beams with the boundaries delineated on orthogonal X–rays of the patients. Beam shaping was limited and typically simple square or rectangular beams were used. Although 2D radiotherapy is now rarely used, it still has a role in palliative treatment.

7. 2DCRT 2DCRT treatment can be delivered by using Phoenix machine, Bhabhatron and LINAC machine. 2D image of cranial tumour

8. 3DCRT Three dimensional conformal radiation therapy (3DCRT) is an advanced technique that incorporates the use of imaging technologies to generate 3D images of patient’s tumour and nearby organs and tissues. The goal of 3DCRT is to deliver a conformal dose distribution to tumours, while sparing the surrounding normal structures. It allows for a high level of precision and accuracy in the delivery of radiation treatment.

9. 3DCRT In 3DCRT, the 3D images can be produced by following imaging modalities  Computed tomography (CT) Magnetic resonance Imaging (MRI) Positron emission tomography (PET) PET–CT Field view of 3DCRT cervix cancer

10. IMRT Intensity modulated radiation therapy (IMRT) is an advanced mode of high-precision radiotherapy that uses computer controlled linear accelerators to deliver radiation doses to a malignant tumour. IMRT allows for the radiation dose to conform more precisely to the 3D shape of the tumour by modulating of controlling the intensity of the radiation beam. Treatment is carefully planned by using 3D CT or MRI images of the patient.

11. IMRT By using IMRT higher and more effective radiation doses can safely be delivered to tumours with fewer side effects compared with conventional radiotherapy. Comparison between 2DCRT, 3DCRT and IMRT

12. IGRT Image guided radiation therapy (IGRT) is a type of cancer treatment that employs imaging technologies like PET, MRI and CT to deliver radiation to cancer cells more precisely and safely. IGRT is used to treat all types of cancer but it is particularly ideal for tumours located very close to sensitive structures and organs. It is also used to treat tumours in areas of the body that are prone to movement such as lungs, liver, prostate etc.

13. IGRT The main benefit of IGRT is that it can  Kill the malignancy, using larger doses of radiation. Prevent causing damage to surrounding healthy tissue. Minimize the radiation side effects. CT is equipped with LINAC

14. VMAT Volumetric modulated arc therapy (VMAT) is a radiation therapy technique in which radiation beam continuously rotates isocentrically around the patient. In this technique one or more sectors of a 360  rotation are skipped to reduce the dose to critical normal structures. It is suitable for small, symmetric, deep seated tumours and usually limited to field sizes less than approximately 10 cm in width for the treatment of centrally located tumours.

15. VMAT The prostate, bladder, cervix and pituitary are critical sites that can be treated by using VMAT techniques. Rotation of gantry in VMAT technique

16. SBRT Stereotactic body radiation therapy (SBRT) refers to delivery of highly conformal radiation dose to the target volume by using multiple fractions. It involves the use of image guidance that indicates the exact 3D location of tumours, so that the radiation can be more precisely delivered to cancer cells. This procedure uses many focused radiation beams to treat tumours all over the body.

17. SBRT SBRT is typically used to treat small, early stage lung cancer and the cancer of pancreas, liver, adrenal gland, spine etc. SBRT has shown dramatically better outcomes than conventional radiation therapy as with the help of SBRT, physicians are able to deliver a greater combined dose of radiation over the course of far fewer treatments.

18. SRS Stereotactic radiosurgery (SRS) refers to the precise and focused delivery of a high dose of radiation in a single session which minimizes the damage of healthy tissue. It is not surgery in the traditional sense because there is no incision. Instead, SRS uses 3D imaging to target high doses of radiation to the affected area. This technique uses advanced imaging technologies combined with sophisticated computer guidance to deliver a high dose of photon radiation.

19. SRS SRS has become an increasingly common approach for patients having  Deep brain tumours Pituitary tumours Cancer of eye Tumours in the lung Tumours in the liver Tumours in the spine Cancer of nasal cavity

20. SRS SRS can be delivered in 3 types  i . Cyber knife Cyber knife radiosurgery is a precise, painless, non-invasive radiation treatment where high radiation X–ray beam is delivered from multiple points outside of the patient body. Patient is treating under Cyber knife machine

21. SRS ii. Gamma knife Gamma knife surgery is a computer guided treatment that delivers highly focused radiation to tumours and lesions in the brain. An Elekta’s leksell gamma knife machine

22. SRS iii. X knife X knife is a non-invasive radiation treatment which is able to treat the tumours anywhere in the body in 1–5 fractions. It is also known as LINAC based stereotactic radiosurgery as it uses 6 MV linear accelerator. LINAC based radiosurgery Or X knife