Radiotherapy and Its Side Effects: Chapter 1 - Introduction

PART II

Chapter 1

Introduction (cont'd)

Radiotherapy has been used for both curative and adjuvant cancer treatment for many years. Adjuvant therapy refers to auxiliary/additional treatment for cancer; adjuvant radiotherapy is usually given after surgery or in conjunction with chemotherapy when a potential risk of relapse remains. Radiotherapy can also be given before surgery to reduce the mass of tumor to be removed.

Roughly speaking, 60% of all cancer patients receive radiotherapy, thus, radiotherapy might not be necessary for all cancer cases. For example, according to a scientific report in the New England Journal of Medicine, it was indicated that children with the most common form of leukemia can safely forego radiation therapy if they are treated with chemotherapy regimens tailored to their individual needs. The conclusion was based on a clinical trial involving 498 patients with acute lymphoblastic leukemia.  Nearly 94 percent of the patients were still alive 5 years after treatment, a result that compares favorably with other treatment studies.

An overly simplified schematic representation of how radiation works is shown in Fig. 2.1. Basically, radiation therapy works by damaging the DNA of cancer cells and hampering these cells from replicating. The damage to cancer cells is caused by radiation, which directly or indirectly breaks up the DNA chain. The indirect damage comes from free radicals including hydroxyl radical (HO^·), superoxide  (O₂^-), hydrogen peroxide (H₂O₂), peroxyl (ROO^·) and alkoxyl (RO^·) radicals, collectively called reactive oxygen species (ROS).  

Fig. 2.1   Schematic representation of how radiation works

© Jiajiu Shaw, 2020

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. All contents posted are extracted from the book, "SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY", prepared by Dr. Jiajiu Shaw, Dr. Frederick Valeriote, and Dr. Ben Chen. 

Side Effects of Chemotherapy and Radiotherapy: Preface

     Cancer is a group of diseases with similar characteristics, out-of-control growth of cancer cells. Conventional cancer treatments include surgery, chemotherapy, and radiotherapy. Although technology advancements have made vast improvements in the last two decades or so, there is no perfect treatment for cancer because of its complexity; one of the major issues related to cancer treatment is the unwanted side effects.

In the upcoming series, we will focus on the side effects induced by chemotherapy and radiotherapy. We will briefly introduce chemotherapy and radiotherapy; we will also describe the side effects, current methods to tackle the side effect issue, and how to manage the side effects.

The purpose of this coming series is to help people understand the potential side effects of chemotherapy and radiotherapy. However, it is important for you to know that this blog is not intended to substitute the expertise and judgment of your physicians or other medical practitioners.

Although the upcoming series related to side effects of chemotherapy and radiotherapy can be somewhat technical, people with some technical background in chemistry/biochemistry should be able to read through without much difficulty.

Finally, if this blog is useful for you in any way, please share it with your loved ones and friends.

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. Most of the contents posted are extracted from the following books: (1) IS CANCER IN US, and (2) SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY. 

Methods of Cancer Treatment, Summary

Methods of Cancer Treatment - Summary

So far, we have discussed a number of cancer treatment methods, conventional and novel methods.  Each method has its own advantages and disadvantages.  Although significant progresses have been made in some of them in recent years, it seems like there is no perfect way to treat cancer at the present time.  Why? 

Remember that most cancer cells are mutated and transformed from normal/stem cells through problematic mutations; the problematic mutations could be only one out of many thousands of mutations.  Thus cancer cells are just like brothers/sisters of normal cells and similar in many ways.  This is what makes it so difficult to treat cancer.  In addition, any treatment that contravenes the growth of cancer cells might also affect normal cells, thus resulting in side effects.  Fortunately, modern technologies in surgery, chemotherapy, and radiotherapy have made significant progresses in reducing the side effects (i.e., injuries of normal cells).  

If there is a perfect way and it’s easy to deal with, we wouldn’t have many thousands of scientists in the world working day and night on finding better answers.  The way the world is created by nature, we are going to have a difficult time to find a perfect way to treat cancer.  However, researchers are making progress inch by inch; newer and better methods have been developed in the last 50 years or so and there will be more and more improvements discovered in the coming years to fight against cancer.

In my opinion, stem cell related therapies have the best chance to be among the best methods for treating cancer.  Among them, two strategies are most appealing to me; they are (1) potential treatment by exosomes, and (2) reversing cancer cells back to normal cells.  However, a lot of technical hurdles must be overcome before either can become practical.  In any case, I believe this is an exciting period of time for the research and development of cancer treatment. We are also putting some of our efforts in this general area and hope to make some contributions. 

Although there may not be a perfect therapy for cancer treatment at the present time, there are a few good ways to reduce the risk of getting cancer and/or to slow down cancer growth.  Other than the methods described previously, there are other aspects to consider in order to reduce the chances of getting cancer.  We will talk about these later. 

© Jiajiu Shaw, 2016

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. Although some commercial products, publications, and services are mentioned in this blog, the author does not endorse any specific products, publications, or services.  None of the contents in this blog represents or warrants that any of the products, publications, or services is appropriate or effective for their intended purposes. Readers shall always seek the advice of their physicians or other medical practitioners with any questions regarding personal health or medical conditions and shall be solely responsible for their own decisions and/or actions.

Novel/Unconventional Methods for Cancer Treatment (1)

In addition to the three classic/conventional methods of cancer treatment mentioned before, there are some novel and/or unconventional methods for cancer treatment that are worth mentioning. Some of these methods are being used, although not widely available, and some are still under clinical development and not yet available. Examples of these novel and/or unconventional methods as well as some novel strategies of cancer drugs are briefly described below.

1. Using Electromagnetic Waves to Treat Cancer

Electronic devices that emit some form of electromagnetic waves have been investigated for cancer treatment for a few years. Although there are a number of electronic devices under development as potential devices for cancer treatment, there is only one device recently approved by the FDA for brain tumor treatment. The device is called Optune (by Novacure), which includes a portable electric field generator, transducer arrays, and rechargeable batteries. The device works by creating alternating wave-like electric fields which interact with the dividing cancer cells, therefore, slow down the multiplication of cancer cells.

Clinical studies showed that, when used in combination with temozolomide (the most prescribed brain cancer drug), Optune was effective in treating glioblastoma (brain cancer) and significantly extended patients’ lives. 

All contents posted in this blog are extracted from the book "IS CANCER IN US", available at Amazon.

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. Although some commercial products, publications, and services are mentioned in this blog, the author does not endorse any specific products, publications, or services.  None of the contents in this blog represents or warrants that any of the products, publications, or services is appropriate or effective for their intended purposes. Readers shall always seek the advice of their physicians or other medical practitioners with any questions regarding personal health or medical conditions and shall be solely responsible for their own decisions and/or actions.