NEED SPECIFICATION DOCUMENT

Sivashyam Sundar A

EE11B103

NEED:

A method to increase the precision and configurability of the Radiofrequency

thermal ablation process in Cancer treatment which will increase the scope of

its application.

OBSERVATION: Radiofrequency thermal ablation (RFA) is a minimally invasive process which is

used to kill the cancer cells in a tumour. The size and location of the tumour is

critical to the process and current technology limits the application of this to a

small range of cancer tumours. RFA expands the medical application of heat,

which for decades has been used as a cautery device to cut tissue.

The following are the basic steps in a RFA process:

The tumours are located with ultrasound, computed tomography (CT), or

magnetic resonance (MR) imaging devices.

Then the patient is essentially turned into an electrical circuit by placing

grounding pads on the thighs.

A small needle-electrode with an insulated shaft and an un-insulated

distal tip is inserted through the skin and directly into the tumour. Ionic

vibration at the needle tip leads to frictional heat.

After 10 to 30 minutes of contact with the tumour, the radiofrequency

energy kills a 2.5- to 5-cm sphere. The dead cells are not removed, but

become scar tissue and eventually shrink.

Please refer to Appendix A for a more detailed procedure of the RFA process.

The primary application of RFA is in the treatment of primary or secondary

liver cancer, primary or secondary lung cancer and kidney cancer. The

application of RFA extends to other types of tumours as well.

The RFA procedure however, has its own limitations. This is because the

current technology cannot be applied in curing tumours of larger radius or

tumours near sensitive tissues. The need aims at developing a better RFA

technology which will help reducing such limitations. The following Disease

State Analysis will be taking into account only Liver cancer as there is more

scope of expansion of the current RFA technology to curing liver cancer

ANATOMY AND PHYSIOLGY: This part will deal with the anatomy and physiology of the Liver.

The liver is the largest solid organ in the body. In adults, the liver can weigh up

to 1.5 kilograms (kg). It is in the upper-right abdomen, just under the rib cage

and below the diaphragm (the thin muscle below the lungs and heart that

separates the chest cavity from the abdomen). The liver is part of the digestive

system.

STRUCTURE:

The liver has 2 main lobes: the larger right lobe and the smaller left lobe. Each

lobe is divided into segments.

The lobes are separated by a band of tissue called the falciform ligament (also

called the broad ligament), which helps attach the liver to the diaphragm.

A layer of connective tissue, called Glisson’s capsule or the capsule, covers the

liver.

BLOOD VESSELS:

Unlike most other organs, the liver has 2 major sources of blood:

Portal vein – carries blood from the digestive system to the liver.

Approximately 75% of the liver’s blood supply comes from the portal

vein.

Hepatic artery – supplies the liver with oxygen-rich blood from the

heart.

Most of the blood is removed from the liver through 3 hepatic veins (the right,

middle and left hepatic veins) found inside the liver.

BILE DUCTS:

The liver, gallbladder and small intestine are connected by a series of thin tubes

called ducts. One function of the liver cells (hepatocytes) is to produce bile. Bile

is a yellow-green fluid that helps digest fat. Bile travels through a series of ducts

in the liver to the small intestine or to the gallbladder for storage. Bile is

collected from the liver in hepatic ducts. Two hepatic ducts leave the liver and

join to form the common hepatic duct. The cystic bile duct leaves the

gallbladder and joins the common hepatic duct to form the common bile duct.

FUNCTION:

The liver performs the following important functions in the body:

Produces bile

Absorbs and uses (metabolizes) bilirubin

Helps the body make blood-clotting (coagulation) factors

Helps the body metabolize fat

Metabolizes protein

Metabolizes carbohydrates

Stores vitamins and minerals

Filters the blood.

PATHOPHYSIOLOGY: Hepatocellular Carcinoma (HCC) is the most common form of liver cancer. The

pathophysiology of the same has been discussed here.

Initially the presence of HBV was linked to the development of HCC but it was

dismissed later. It was discovered then that most cases of hepatocellular

carcinoma developed in patients with underlying cirrhotic liver disease of

various etiologies. Inflammation, necrosis, fibrosis, and ongoing regeneration

characterize the cirrhotic liver and contribute to hepatocellular carcinoma

development.

The disease processes, which result in malignant transformation, include a

variety of pathways, many of which may be modified by external and

environmental factors and eventually lead to genetic changes that delay

apoptosis and increase cellular proliferation.

Thus HCC occurs predominantly in patients with underlying chronic liver

disease and cirrhosis. The cell(s) of origin are believed to be the hepatic stem

cells, although this remains the subject of investigation.[3] Tumours progress

with local expansion, intrahepatic spread, and distant metastases. Tumours may

present as a single mass lesion or as diffuse growth. The presentation may be

caused in part by mass effect that can lead to obstruction of the biliary system

or anywhere affecting the liver vasculature. Without aggressive surgical

resection, ablative therapy, or liver transplantation, hepatocellular carcinoma

results in liver failure and eventual death.

The staging of liver cancer is done in a lot of ways. There is no universally

accepted system for staging it. The treatment staging procedure is the simple to

understand method and clearly suggests the treatment. The 3 treatment stages

of liver cancer are:

1. Localized, resectable:

There is only one tumour in part of the liver or a limited number of

tumours in only one lobe of the liver.

The cancer is at an early stage and has not spread to other parts of the

body.

The person has good liver function (Child­-Pugh grade A).

2. Locally advanced (regional), unresectable:

The tumour is too large to be removed with surgery.

The tumour has grown into the blood vessels in the liver.

The person has poor liver function.

3. Advanced:

The cancer has spread throughout the liver or to other organs in the

body.

CLINICAL PRESENTATION:

SIGNS AND SYMPTOMS:

Pain in the abdomen

Lump or mass under the ribs

Jaundice

Weight loss

Fatigue

Weakness

Changes to digestion

Change in bowel habits

Malaise

Swelling of the legs and feet (edema)

Hepatic encephalopathy

o confusion

o forgetfulness

o drowsiness

o personality changes

o breath with a sweet or musty odour

o unconsciousness, coma

Portal hypertension

DIAGNOSIS:

Serum AFP would appear to be an attractive option for screening given its low

cost and morbidity. Unfortunately, it is only 40-64% sensitive because many

tumors do not produce AFP at all or only at a very advanced stage. When

elevated, the AFP is 75-91% specific and values greater than 400 ng/mL are

generally considered diagnostic of hepatocellular carcinoma.

The best imaging modality for screening remains the subject of debate.

Ultrasonography offers a relatively inexpensive method of screening.

Ultrasound as a screening method is reported to have 60% sensitivity and 97%

specificity in the cirrhotic population, and it has been demonstrated to be cost

effective.

CLINICAL OUTCOMES:

MORBIDITY:

Often liver cancer is not found until it is at an advanced stage, which can

make it more difficult to treat.

Most liver cancers have a tendency to spread quickly.

An underlying liver disease, such as cirrhosis, can affect survival.

The severity of the desease can be associated with the stage of the disease:

1. Localized, resectable

There are 1 or 2 tumours in 1 lobe of the liver.

These tumours can be removed (resected) by surgery.

2. Locally advanced (regional), unresectable

There are several tumours that have spread to the other lobe or other

parts of the liver and have spread to the lymph nodes.

These tumours are locally advanced and cannot be removed by

surgery.

3. Advanced

1. The cancer has spread to distant organs.

MORTALITY:

Mortality in cancer diagnosis is generally given by the 5-year survival rate

which means the number of people who live 5 years after their cancer is

diagnosed.

1. Localised- 28%

2. Locally advanced- 7%

3. Advanced- 2%

For all stages combined, the relative 5-year survival rate is about 15%

EPIDEMIOLOGY: Liver cancer is the sixth most common cancer worldwide, with more

than 782,000 new cases diagnosed in 2012 (6% of the total).

Liver cancer incidence rates are highest in Eastern Asia and lowest in

South Central Asia

Liver Cancer in developing nations is over twice the incidence of that in

developed countries.

The highest incidence of hepatocellular carcinoma is in East Asia, with

incidence rates in men of 35 per 100,000 population, followed by Africa

and the Pacific Islands.

Liver cancer incidence is strongly related to age, with the highest

incidence rates being in older men and women. In the UK between 2009

and 2011, an average of 43% of cases were diagnosed in men and women

aged 75 and over, and 81% were diagnosed in those aged 65 and over

As far as prevalence is considered, worldwide, it is estimated that there

were more than 613,000 men and women still alive in 2008, up to five

years after their diagnosis.

ECONOMIC IMPACT: Cancer has a huge economic impact worldwide. Every year millions of dollars is

spent n Cancer research, treatment and concessions by the governments.

In 2013 Cancer Research UK spent about 351 Million pounds on research and a

specific 21 Million was spent on providing information for people affected by

cancer.

However much economic details are not available for Liver cancer specifically.

SUMMARY: The report summarised the Disease state of Liver cancer. It is evident that it is

one of the deadliest diseases and a hard and fast treatment method is yet to be

discovered. In fact, this is the case for any cancer type. Hence, the importance

of biomedical device innovation comes into picture.

TREATMENT OPTIONS: There are a variety of treatment options depending on the stage of liver cancer.

We are considering all the treatment options for primary/secondary liver

cancer because it helps in identifying the gaps and whether or not

improvements in RFA technology will be able to fill them.

OVERVIEW OF TREATMENT OPTIONS:

Methods Procedure Benefits Drawbacks

1)Liver Transplant Done for: 1)Single tumour- 5cm or less 2)5 tumours- 3cm or less 3)Single 7cm tumour which didn’t grow in 6 months

Helpful for people with long term liver damage from alcohol or Hepatitis.

1)Cannot be done for severe cirrhosis 2) if cancer has spread outside the liver transplant will not cure it 3)Finding donors can even take 6 months

2) Liver resection Part of the liver is removed to destroy the cancer cells. The removed tissues can grow back in matter of weeks.

Highly effective for Fibrolamellar Hepatocellular cancer which does not include Cirrhosis

Growth of liver is delayed if cirrhosis is present.

3) Radiofrequency/ Microwave ablation

The treatment uses radio waves/microwave to destroy cancer cells by a minimally invasive procedure

1)It is a very simple process and patients can return to normal selves in a short time. 2)Can be used for any type of liver cancer with tumours of size 3-4 cm

1)Possibility of growing back 2)Possibility of damaging surrounding tissues. 3) Cannot be done for larger tumours

4)Percutaneous Ethanol Injection (PEI)

Alcohol is injected into the tumour to cut off blood supply by dehydrating the tissue.

A fairly simple procedure without much complications

1) Side effects include high temperature fever. 2)Requires more than one session 3)Applicable only for very small tumours

5) Chemoembolization/ Chemotherapy Radioembolization/ Radiotherapy

It will cut off the cancer’s main blood supply with the aid of drugs/radiation. Radioembolization procedures also help destroying cancer cells by radiation.

Works well is preventing the growth and controlling symptoms of cancer

1)Not a standalone treatment procedure. 2) Cannot cure HCC which is the common of liver cancer 3)Radiotherapy is generally not used for liver cancer

CLINICAL TREATMENT PROFILE:

Mechanism of action:

The primary aim Cancer treatment procedures is to kill the cancer cells.

Liver transplant, Resection, RFA, PEI directly kill the cancer cells by the

use of invasive procedures.

PEI and Chemoembolization destroy cancer cells by cutting off the blood

supply to the tumour area.

Indications:

The cancer treatment procedures are generally selected on the basis of

the size of tumours and the spread of the disease.

Older people are not subjected to extreme treatments like surgery but are

often kept under palliative care with the help of Chemotherapy.

Children with Hepatoblastoma, a type of cancer are subject to

Chemotherapy as it works best on them.

Since most adults are diagnosed with cancer at advanced stages about

only 1 in 10 people with liver cancer are subject to surgical methods.

Also, if cirrhosis likely developed because of alcohol is present then

surgical methods cannot be used.

Efficacy:

The outlook for people who are diagnosed in early stages and undergo

liver transplant is the best currently. About 75% of them survive after 5

years from diagnosis.

Overall, only between 1 in 6 people (15%) and 1 in 4 people (25%) live for at

least 5 years after surgery to remove liver cancer (liver resection).

People who have cancers that are less than 3cm across, more than half

(50%) will live for more than 5 years because of procedures like RFA and

PEI.

Safety:

All the treatment procedures almost invariably have side effects.

Liver transplant is too big an operation to survive if the patient is already

very ill. Also, the drugs taken to make the body accept the new liver

damp down the activity of your immune system and reduce its ability to

control the cancer.

Liver resection possibly does not have any special side effects but it has

the usual side effects of a surgery and takes a toll on the patient.

RFA and related technologies may damage the nearby good tissues and a

complete fullstop to the cancer cells may not be guaranteed.

Chemotherapy leads to Sickness, diarrhoea, hair loss or thinning, feeling

tired and run down, sore mouth or mouth ulcers, a drop in blood cells

causing an increased risk of infection, bleeding or bruising, tiredness and

shortness of breath.

Chemoembolization may result in liver failure in patients with moderate

or higher level of Cirrhosis..

TREATMENT LANDSCAPE:

Summary of treatment options:

Risk Benefit analysis:

Treatment Option Benefit Risk

1) Liver Transplant Will get rid of any complication related to liver and has the highest 5 year survival rate among all treatment options.

1)It’s a complicated operation and has its own significant mortality rate 2)Post-operative drugs will dampen the immune system

2)Liver Resection Up to 80% of the liver can be removed and can be grown back.

Liver failure is likely in people with cirrhosis

Liver Cancer

Hepatoblastoma in kids

Chemotherapy along with surgical aid

Preliminary

Stage

Without Cirrhosis

Tumour of any size

Liver Resection

In combination with surgery/other treatments

Chemotherapy

With Cirrhosis

Single tumour tumour < 5 cm or multiple tumours

with < 3 cm

Liver Transplant

Tumour < 3-4 cm

RFA

Tumour < 2cm

PEI

Advanced Stage

Palliative care using

Chemo-therapy/embolization

Radioembolization

3)RFA/Microwave ablation Minimally invasive procedure with very low complications

Side effects like necrosis, pain and fever.

4)PEI Can be done just by using ultrasound and has very less complications

High fever and pain

5)Chemoembolization/ Chemotherapy

Keeps growth under control Can result in liver failure

Cost/benefit analysis:

Cost

Benefit

Liver

Transplant

Liver

Resection

RFA, PEI

Chemo therapy

The cost benefit analysis considers the utility provided by the treatment and the

relative cost.

As can be seen in the table, though Liver Resection is limited to patients with no

or low cirrhosis, it is more effective than RFA when performed.

GAP ANALYSIS:

From the analysis of treatment options we not the following points:

There is no definitive method for advance stages of liver cancer

RFA methods are limited to sites which are not critical tissues and the

maximum radius of tumour that can be ablated is 5 cm.

Surgery methods though have higher benefits, are complicated

procedures and a good health condition is needed which de facto is not

present in a cancer patient.

One major advantage of RFA procedure is that it neither has limitations on the

health condition of the patients nor on presence of other complications. Rather

it is limited by the size and site of the tumour. The collateral damage done

because of RFA include the tissue surrounding the tumour.

This can be cured by RFA

This cannot be treated by RFA as the tumour has grown

on the blood vessel

Thus, by increasing the accuracy of RFA technology we can extend the range of

application of the process, thereby providing a providing treatment to tumours

larger sizes for patients who cannot undergo other procedures

STAKEHOLDER ANALYSIS: The stakeholder analysis is done taking into account the benefits/costs the

stakeholders will face if the need is achieved.

CYCLE OF CARE:

Patient

Primary Physician

Diagonostic Procedures

Hepatologist

Stage 1(RFA, PEI, surgery)

Radiologist

Surgeon

Stage 2(Surgery)

Surgeon

Stage 3(Surgery, Chemotherapy)

Surgeon

Oncologist

Stage 4 (Chemotherapy)

Oncologist

Gastroenterologist

FLOW OF MONEY:

OUTCOMES OF STAKE HOLDER ANALYSIS:

Stake Holder Perceived benefit Primary Cost Net Effect

1)Patient 1)Increased chance of survival 2)Better definitive treatment option 3)Cost minimization

Nil Highly positive

2)Relatives 1)Lesser confusion in choosing a treatment option 2)Minimized costs 3)No long periods of hospitalization so less care is needed

Nil Positive

3)Primary physician Better care of the patient

Nil Positive

4)Radiologist 1)More patients 2)Easier technology

Pressure on the radiologist may increase but not significantly

Positive

5)Surgeons Lesser cases of liver transplants meaning lesser demand for liver. Hence needy patients can easily be cured by surgery .

Fall in number of patients

Negative

6) Oncologist Nil Drop in number of chemotherapy patients but not significantly

Slightly negative

7) Equipment providers

A new opportunity for sales, marketing and portfolio expansion

More investment, R&D Positive

8) Insurance Company Lower hospitalization and treatment cost

1) Including newer services covered under insurance 2) Disatisfaction of customers

Positive

9)Facility Provider 1)First in the market distinction 2)More patients

Installing of new equipment and training costs

Neutral

MARKET ANALYSIS:

MARKET SIZE AND SEGMENTATION:

The worldwide market for liver cancer is big and growing. Here are the key

stats accounting for the market.

Incidence:

More than 700,000 people are diagnosed with liver cancer each year.

Liver cancer accounts for 600,000 deaths worldwide each year.

More than 95% of people diagnosed with liver cancer are 45 years of age

or older.

4,348 people in the UK were diagnosed with liver cancer in 2011.

There were 4,514 deaths from liver cancer in the UK in 2012.

Prevalance (for population in UK):

1 Year Prevalence 5 Year Prevalence 10 Year Prevalence

Male 709 1,380 1,727

Female 404 728 899

Persons 1,113 2,108 2,626

The following graphs show some segmented statistics for Liver cancer:

MARKET DYNAMICS:

The market for RFA systems is dominated by BioMed giants like Boston

Scientific, Stryker, Covidien, Angiodynamics. The development of an advanced

technology for RFA can either be sold as an IP to these giants or can be used to

establish a new company.

However with the already established giants it is going to be difficult to create a

new product with little modifications and be successful with it. Also there are

problems of brand value.

Hence the more feasible solution is to develop a technology and sell the IP to

the already established companies.

MARKET NEEDS:

Need of segments:

As can be seen from the statistics, a better technology is always welcomed in

cancer. Research is going on in every part of the world to improve the everyday

life and reduce the mortality rate of cancer.

Radiofrequency Ablation process has already been quoted as an emerging

technology and hence more and more people are seeking to benefit from it

instead of choosing conventional surgical/chemo methods. The main barrier in

this technology being the accuracy of the tech because of which tumours in

critical tissues cannot be cured.

An improvement in the accuracy would even mean a breakthrough depending

upon the extent of improvement. However, this might significantly affect the

income of surgeons. But, considering the greater good this is an important need

in cancer research.

WILLINGNESS TO PAY:

As far as this technology is concerned it results in almost the same cost like

chemo or other treatment methods for the patient. For the hospitals to it is a

matter of one time investment. Even if the cost of treatment were supposed to

increase the patients are willing to pay as this is going to be a less painful

method than surgery and chemotherapy.

The target market will be all the cancer treatment centres and research

institutes.

NEED CRITERIA:

DEMANDS:

Should be able to destroy tumour cells of radius < 5 cm without

damaging the surrounding tissue.

Should be able to destroy larger tumour cells with the accuracy of

existing technology.

Should have a method to accurately position the tip of the electrode.

ENHANCEMENTS:

A robot steered positioning which will automatically position the tip and

move inside if needed.

WISHES:

The cost of new technology should be the same the older technology by

using additional

REFERENCES:

http://www.macmillan.org.uk/information-and-support/treating/supportive-and-other-

treatments/other-treatments/radiofrequency-

ablation.html?utm_source=content&utm_medium=clickthrough&utm_content=radiofreque

ncyablation&utm_campaign=factfile#tcm:9-19847

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http://www.hopkinsmedicine.org/liver_tumor_center/conditions/cancerous_liver_tumors/h

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survival/?region=on

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outlook-for-liver-cancer

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t/acspc-027766.pdf

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primary-liver-cancer

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information-comes-from

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country/article1-837216.aspx

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http://www.angiodynamics.com/products/what-is-rfa

APPENDIX A: RADIOFREQUENCY TUMOUR ABLATION PROCESS

Radiofrequency thermal ablation can usually be performed as an outpatient

procedure under general anesthesia or conscious sedation. Alternatively, RFA

may be performed laparoscopically or during open surgery.[36]

Under light sedation, lidocaine or bupivacaine is administered subcutaneously

at the needle entry site and down to the liver capsule. A needle is placed

through the skin and into the tumour with imaging guidance. Treatment

sessions of percutaneous RFA are easily monitored using real-time ultrasound

imaging, computed tomography, or magnetic resonance imaging. Most patients

feel little pain during the procedure and go home the same day or the day after

the procedure, usually with minimal to no pain or soreness, although there is a

spectrum, and some patients will experience severe pain the day of the

procedure.

During a 10- to 30-minute treatment session, nitrogen micro-bubbles gradually

create a hyperechoic area on ultrasound that provides a rough estimation of the

treated tissue, which is 2.5 to 5 cm per 10- to 30-minute treatment sphere. CT,

MR imaging, or positron emission tomography (PET) imaging may provide

more exquisite detail for follow-up verification of the treatment zone and for

finding residual or recurrent neoplastic tissue. Although real-time MR imaging

and CT are available, they are not in widespread use. Ultrasound is a safe,

common, and easy guidance method, although it is somewhat operator

dependent.

Once the needle has been properly positioned within the tumour, the tissue is

heated. At temperatures exceeding 50o C, cells are destroyed. To treat tumours

of different size and shape, the needle is available in different lengths and

shapes of exposed tips.[37]

Energy is transferred from the uninsulated distal tip of the needle to the tissue

as current rather than as direct heat. The circuit is completed with grounding

pads placed on the patient's thighs. As the alternating current flows to the

grounding pads, it agitates ions in the surrounding tissue, resulting in frictional

heat. The tissue surrounding the needle is desiccated, creating an oval or

spherical lesion of coagulation necrosis, typically 2.5 to 5 cm in diameter for

each 10- to 30-minute treatment. These spheres are added together in three

dimensions to overlap and completely envelop the tumour. Ideally, the treated

tissue will contain the entire tumour plus a variable rim of healthy tissue as a

safety margin.

Failure to ablate the entire tumour with clean edges results in regrowth of the

tumour. Depending on the size and configuration of new growth, the patient

may or may not be suited for another treatment session. Over months to years,

as the dead necrotic cells are reabsorbed and replaced by scar tissue and

fibrosis, the size of the thermal lesion shrinks, although the remaining cells are

ideally dead. The possibility of successful surgical resection may be augmented

by decreasing the number of tumours.[38] Treatment of a tumour in one lobe

may broaden the surgical indications of a tumour in the other lobe. Due to the

natural course of the disease, new or recurrent tumours may be suited for

additional treatment sessions as well.

Source: http://www.cc.nih.gov/drd/tumourtherapy.html