Radiotherapy for Hepatocellular Carcinoma

Patients suffering from Hepatitis B and C  infection and, or, alcohol induced liver cirrhosis,  are more prone to develop hepatocellular carcinoma, i.e. liver cancer. Aflatoxin toxicity,   as well as fatty liver, may also make a person more prone to this aggressive cancer, considered among the top few causes of dying due to cancer.

Treatment of this cancer is linked to the general health status of the patient, the health of his liver, the number and size of the cancerous lesions, as well as the presence of the tumour in major vessels, nodes or other organs of the body.

Resection of a part of the liver, or removal of the entire liver, accompanied by transplanting the liver of a donor, has a high chance of resulting in cure. This treatment is, however, generally reserved for patients who  either have a  moderately sized single tumour, or  small tumours  less than 3 in number,  with good general health, and good functional capacity of the liver.

Patients with more extensive tumours, which are still confined to the liver, may undergo local treatments, with a view to controlling the tumour. This is done with the intent of making the  tumour amenable to  surgery  (downstaging), to buy time while the patient is on a waiting list for a donated liver, or, in some situations, as the sole therapy to prolong the life of a patient.

One of the therapies that is used is Trans Arterial Chemo Embolisation (TACE).  Performed by interventional radiologists, TACE involves  insertion of a catheter in the  blood vessel feeding the tumour, instillation of chemotherapy, locally into the tumours, and then closing off the blood supply to the tumour, thus allowing the drug to act locally.

Radiotherapy is the treatment of cancer using X rays. Various sophisticated techniques, that are an integration of advances in  computer software and in treatment machines called linear accelerators, enable safe radiotherapy. Tumours can be targeted better, notwithstanding their irregular shape, proximity to vital organs or movement with respiration or other bodily functions.

Radiotherapy was earlier considered ineffective for liver cancers; improvement in radiotherapy techniques has resulted in improvement in the therapeutic ratio, i.e. the chance of curing the tumour vis a vis the risk of damaging normal organs. With this improvement, high doses of radiotherapy can be administered, leading to  better chances of controlling tumours. Techniques used for this treatment are Intensity Modulated Radiotherapy ( IMRT) and  Volume Modulated Radiotherapy (VMAT), also called RapidArc. These treatments are delivered under image guidance, i.e. the patient is scanned, prior to each radiotherapy session, on the treatment couch itself, for accuracy. This is called Image Guided Radiotherapy ( IGRT). Since, with these mechanisms, the tumour is targeted accurately and the  bowel and normal liver spared well, very high doses of radiotherapy may be delivered in limited number of sessions; this is called Stereotactic Ablative Radiosurgery (SABR) or Stereotactic Body Radiotherapy  ( SBRT).

Stereotactic Ablative Radiosurgery dose colour wash for a lesion in the liver ( outlined in red).

Radiosurgery may be administered as the sole therapy for patients too unwell for surgery. It may also be used as bridge therapy for patients on a waitlist for liver transplant. This has the twin role of preventing progression during the waiting period as well as identifying patients with aggressive tumours that should not be treated with aggressive surgery, anyway.

Another application is as a treatment for patients with a portal vein tumour thrombus ( PVTT). Patient with any vascular involvement are thought to have a poor prognosis. Adding radiotherapy to the treatment protocol, alone , or along with TACE , is thought to improve the outcome for some patients suffering from HCC with PVTT. 

The treatment of HCC using  SABR/SBRT or the more protracted SHORT typically takes 2 - 3 weeks. In case surgery is planned following radiation, it may be performed anytime from 2 weeks to 6 months later.

In conclusion,  surgery is the ideal treatment for HCC. Non surgical options like TACE and SABR/SHORT help prepare patients for surgery as well as offer a possibility of controlling the disease for sometime, in case surgery is not possible.

Modern radiation techniques for treating gynaecological cancers

What are gynecological cancers?­

A. Cancers of the female reproductive organs are called gynecological cancers. Among these are cancer of the body of the uterus (endometrial cancer), opening of the uterus (cancer of cervix), ovary, vagina and vulva.

 Q. What is radiotherapy?

A. Radiotherapy is one of the three methods of treating cancer, the other two being surgery and chemotherapy. Also called radiation or radiation oncology, this modality of cancer treatment involves targeting cancer with x rays or gamma rays and rarely, with  charged particles such as electrons and protons.

Q. What are modern radiation techniques?

A. Modern radiotherapy techniques are treatment methods that consist of computerised  modeling  of patients’ anatomy, software programs that, under direction of a radiation oncologist,  target cancer and protect normal tissues. In addition, synonymous with these techniques is the use of sophisticated hardware, i.e. treatment machines called linear accelerators, which have devices that shape the radiation to match the shape of the tumour. Some advanced linear accelerators also have provision for X rays or CT scans before or during a patient’s treatment session, to ensure accurate focusing of the radiation beam.

Q. How do modern radiation techniques help in better treatment of cervical cancer?

A. Radiotherapy is the main treatment for cervical cancer, except in very early stages when surgery may be used alone or in combination with radiotherapy.  Various modern radiotherapy techniques ensure safe and effective treatment for this cancer. These are IMRT or RapidArc, to reduce the effects of radiotherapy on normal structures adjacent to the cancer, i.e. small and large bowel, urinary bladder and bone marrow. Another technique, IGRT, which may be used in addition to IMRT / RapidArc, is aimed at ensuring accurate treatment by accounting for, and correcting,  changes in the patients position in reference to the treatment machine, i.e. linear accelerator , as well as changes in the internal organs vis a vis one another. The latter happens because of routine body functions like presence of urine, gas and stool  in the bladder and bowel, respectively.

Q. What is brachytherapy and is there some advance in this method too?

A. Brachytherapy is internal radiotherapy, i.e. insertion of a radiation source into the affected organ, delivering treatment in proximity to the tumour. Traditionally planned using x-rays, image guided brachytherapy is an advance wherein the radiation is directed on the basis of CT or MR scan, ensuring a dramatic improvement in efficacy. This is because x ray based planning incorporate neither  information of patients' anatomy nor that of the volume and extent of the cancer in an individual patient.  I practise  MR based brachytherapy   for cervix and am very satisfied  both with the additional  information that is received by doing an MRI as well as the outcomes achieved.

Q. How are intracavitary and interstitial brachytherapy different from each other. Intracavitary radiotherapy , the more common form of brachytherapy in cervical cancer consists of insertion of hollow applicators into the uterus and cervix using the body's normal passage and then inserting a  radiation source into these hollow applicators. Interstitial radiotherapy is used when the disease extends  farther away from the reach of applicators placed in the uterus and vagina.

Q. What has been the impact of these modern radiotherapy techniques on cure rates in cervical cancer? Is this dependent on the treatment machine?

A. There has been a significant improvement in outcomes even in advanced stages of cervical cancer/ cancer cervix. While the equipment is important, the  knowledge & skill set of the treating radiation oncologist and  meticulous attention to detail  by the treating  team, in each patient, is essential to  ensure correct treatment and extract the best from the treatment machine.

Q. What is the role of modern radiotherapy in endometrial cancer (body of uterus)?

A. Primarily treated with surgery, radiotherapy is used as post operative treatment in nearly all stages. The treatment varies according to the stage of the disease; modern radiation techniques have an important role in preventing recurrence of cancer and reducing side- effects. The treatment may comprise of external beam radiotherapy i.e. IMRT / RapidArc with or without IGRT or may be in the form of brachytherapy for the vagina. In some situations, these may be combined.

Q. What about other gynecological cancers?

A. Cancers of the vagina require radiotherapy.   Cancer of the  vulva, i.e. the external reproductive organs may be treated either with surgery or with a combination of radiotherapy and chemotherapy. The primary cancer is treated, along with lymph glands that lie in the groin. Here too, IMRT helps treat the cancer while sparing  adjacent normal organs.

Radiotherapy is used in special situations in the treatment of cancer of ovary.

Alcohol Consumption & the Risk of Cancer

Q1.  Does consuming alcohol increase the risk of developing cancer?

A1. Yes, consuming alcohol increases the risk of developing cancer. This risk is more in heavy drinkers but significant in all persons who consume alcohol regularly.

Q2. What are the reasons for this increased risk?

A2. The reasons are varied. Some of these reasons are that alcohol increases inflammation in some organs of the body, leads to nutritional deficiency, increases the amount of the female hormone estrogen in the body and causes obesity.Other factors are reduction of the immunity of the body as well as an increase in the harmful effects of tobacco.

Q3. Does this increased risk pertain to some specific cancers and if so, which cancers are these?

A3. Alcohol increases the risk of cancer of the mouth, throat, food-pipe, large intestine, liver and breast.

Q4. Why does alcohol increase the risk of developing cancer of the alimentary tract, i.e.,  throat, food pipe and  intestine.

A4. Alcohol is metabolised into a toxic substance called acetaldehyde which causes inflammation in the alimentary tract.  In addition, it also potentiates the ill effects of tobacco by increasing  the absorption of carcinogens (cancer causing substances).

Q5. Does alcohol increase the risk of cancer of the breast in older women, or is age irrelevant ?

A5. Alcohol increases the level of oestrogen in the body and this in turn leads to an increased risk of breast cancer, irrespective of the age or menopausal status of a woman. The increased risk of breast cancer is also related to obesity and the deficiency  of folates induced by alcohol.

Q6. Alcohol induces cirrhosis of the liver. Is that somehow related to cancer?

A6. Yes, the same inflammatory process that causes cirrhosis of the liver also causes cancer. Liver cancer is one of the most common causes of cancer related death worldwide, though all of this is not related to alcohol.

Q7. How significant is the problem of alcohol related cancer in the Indian context.

A7.Though less significant than countries like China or the developed world, alcohol is an important cause of cancer in Indian men, with over 7 % of cancers in Indian males being attributed to alcohol. Happily, the number of alcohol induced cancers  in Indian women is negligible.

Q8. Does stopping the intake of alcohol help?

A8. Stopping the consumption of alcohol helps but slowly, the risk of developing cancers becoming equivalent to a non drinker in about ten years.