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Radiotherapy has been an integral part of cancer treatment for decades now. It plays a crucial role along with surgery and chemotherapy in managing many common as well as complex cancers. With advancement in technology, radiotherapy today has become one of the most precise treatment methods available for cancer with minimal side effects. Let’s understand more about this important treatment approach and how it is helping cancer patients.
What is Radiotherapy?
Radiotherapy, also known as radiation therapy, involves using high-energy beams such as X-rays, gamma rays, electron beams, protons or other charged particles to destroy cancer cells and shrink tumors. The radiotherapy beams are targeted accurately only at the area containing cancer cells with the help of sophisticated computer planning techniques and modern radiation machines. The main aim of radiotherapy is to eliminate cancer cells while sparing surrounding normal tissues as much as possible.
Types of Radiotherapy
Radiotherapy is commonly delivered in the following forms:
– External Beam Radiotherapy (EBRT): It involves delivery of high-energy radiation beams from outside the body through a machine called a linear accelerator. EBRT is the most common type used for treating over 90% of cancer patients requiring radiotherapy. It can be delivered in many ways according to the tumor site and stage.
– Brachytherapy: It involves implanting radioactive material directly into the tumor area or its vicinity. The radioactive sources are placed inside thin tubes or catheters. Brachytherapy delivers a very high dose of radiation precisely to the tumor while sparing surrounding healthy tissues. Cancers of cervix, prostate, breast, skin are common sites treated with brachytherapy.
– Intraoperative Radiotherapy (IORT): As the name suggests, it involves delivery of a single high dose of radiation to the tumor bed during cancer surgery before the surgical area is closed. This type of treatment is utilized for certain breast cancers and some soft tissue sarcomas.
– Proton Beam Therapy: It employs beams of protons rather than X-rays to treat tumors. Protons deposit most of their energy at a certain depth in tissues rather than exiting the body, therefore allowing delivery of higher radiation doses to the tumor with less exposure to nearby normal tissues. Proton therapy is useful for treating head & neck, lung, prostate and other abdominal/pelvic cancers, especially in children.
Role in Cancer Management
Radiotherapy plays an indispensable role in the management of cancer patients at various stages:
– Curative or radical intent: It is used with potentially curative intent in combination with surgery for high-risk early stage cancers like head & neck, breast, prostate, rectal cancers which are at higher risk of recurrence. Radiotherapy helps eliminate any residual cancer cells.
– Palliative intent: Radiotherapy is frequently utilized for palliation of symptoms in advanced or metastatic cancers by treating painful bone or soft tissue metastases, obstructed passages etc. It significantly improves quality of life for such patients.
– Adjuvant/Neoadjuvant intent: Radiotherapy given before or after cancer surgery is called neoadjuvant or adjuvant radiotherapy respectively. It helps destroy any subclinical cancer spread or reduces risk of recurrence and improves survival outcomes in multiple cancers.
Technological Advancements
Over the past few decades, radiotherapy techniques and machines have become highly advanced due to incorporation of modern technologies such as:
– Intensity-Modulated Radiation Therapy (IMRT): It delivers non-uniform radiation doses to the target area using various beam intensities. IMRT allows sculpting the high dose region closely to the tumor shape while avoiding adjacent critical structures.
– Image Guided Radiation Therapy (IGRT): Advanced imaging like CT, cone beam CT or MRI is integrated into the treatment process for precise patient positioning and tumor localization each time before treatment delivery. This ensures radiation is targeted accurately.
– Stereotactic Radiosurgery/Ablative Radiotherapy (SRS/SABR): It employs multiple convergent radiation beams with steep dose gradients to deliver ablative radiation doses to tumors in 1-5 fractions instead of conventional 30-40 fractions. SRS/SABR is utilized for brain, lung, liver, spine and other oligometastatic tumors.
– Particle Therapy: Advanced particle therapy centers offer proton or heavy ion beam radiotherapy for select cancers with improved dose distribution compared to photons and less potential long term side effects.
– Personalized predictive modeling: Developments in radiomics and artificial intelligence are enabling more personalized treatment approaches through predictive modeling of tumor response and toxicity risks.
Future Prospects
With ongoing research in physics, biology and computational sciences, radiotherapy is all set to make further leaps in the coming years through technologies like:
– FLASH Radiotherapy: Delivery of ultra-high dose rates in fraction of seconds may overcome tumor biology limitations and allow safe dose escalation with minimal damage to normal tissues.Clinical trials are in progress.
– MR-Linacs: Integration of MRI scanners with linear accelerators allows treatment adaptation based on daily tissue changes and functional imaging for ultimate customization and precision.
– In vivo dosimetry: Real-time in-vivo tracking of radiation delivery through volumetric imagers, MOSFET detectors or prompt gamma monitoring may detect errors instantaneously and ensure complete accuracy.
– Proton Arc Therapy: Continuous 360 degree couch rotation during proton beam delivery will enable faster treatments with highly conformal dose distributions and patient comfort.
Thus, with relentless innovations, radiotherapy is all set to revolutionize cancer care even further both in terms of treatment effectiveness as well as patient experience in the next decade.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
