Chemotherapy and Radiotherapy ☺️

Question 1

What are the goals of chemotherapy and radiotherapy

Answer 1

Curative - get rid of all cancer cells
Control - shrink/slow growth and spread
Relief - shrink to reduce pain, address symptoms (palliative)

Chemo

Radio
Curative - some toxicity acceptable (high dose, long course)

Palliative - min toxicity (low dose, short course)

• SC, cauda equina compression (ONCOLOGICAL EMERGENCY)
• bone mets - prevent fracture, pain control
• brain mets - chemo does not pass BBB
• obstruction/compression from large masses

Question 2

How do they both work

• chemo
• radio

Answer 2

Chemo - meds circulate around bloodstream and act systemically
-can be administered in a variety of ways

Radio - high energy X-rays that aims to cause local double strand DNA breaks

• ext beam
• brachytherapy - temporary/permanent insertion of radioactive seeds near tumour
• radioactive isotopes therapy - swallow isotope

Question 3

SE

• chemo
• radio

Answer 3

Chemo, general SE, majority are reversible

• fatigue
• hair loss
• myelosuppression => pancytopenia - anemia fatigue, easy bruising and bleeding, infection prone (neutropenic sepsis)
• N+V+D
• cardiomyopathy, lung, nerve damage
• infertility - LESS REVERSIBLE
• 2ndary cancer in future

Radio, general SE

• dry, blistering skin inflammation at site => scarring and sensitivity
• fatigue, stiffness
• 2ndary cancer in future

Question 4

Acute and late SE of radio

• brain
• H+N
• chest
• abdo
• pelvis

Answer 4

Brain
A N+V, fatigue
L cognitive, memory problems

H+N
A  hair loss, mucositis
L  eyes, cataracts
L  dry mouth, dental problems, mandible necrosis
L  hypothyroidism

Chest
A esophagitis, pneumonitis, chest tenderness
L lung fibrosis
L ischemic, myocardial issues, pericarditis

Abdo
A N+V+D
L intestinal irritability, kidney, liver damage

Pelvis
A  diarrhoea
A  cystitis
L  proctitis
L  impotence, infertility, menopause, vaginal dryness

Question 5

How would you manage radiotherapy patients

• weekly review
• symptomatic treatment
• long term

Answer 5

Therapeutic ratio - BALANCE BETWEEN TUMOUR CONTROL AND COMPLICATIONS

Weekly review
Preventative measures
-skin care advice - gentle washing
-antiemetics (prochlorperazine)
-oral hygiene 
-dietary review - radiotherapy plan specific to current body shape and weight

Symptomatic treatment

• loperamide - diarrhoea
• analgesia
• nutritional support
• skin reaction treatment
• rest from treatment

Follow up for late effects

• screening for new cancers
• treatment for any lost function (thyroxine replacement for thyroid cancer)

Question 6

Uses of both radiotherapy and chemotherapy

Answer 6

Can be the

• only treatment
• multimodality treatment with surgery and chemo/radio
• reduce recurrence
• neoadjuvant

Question 7

What are the 5 main groups of cytotoxic chemotherapy drugs

-how do they work?

Answer 7

Alkylating agents - crosslinking, incorrect base pairing => DS breaks

Antimetabolites - nucleotide masquerades
-affect S phase

Anti microtubule inh - target metaphase, stop the cell cycle

Cytotoxic ABx - interrupt cell division

Topoisomerase inh - supercoiling => DS breaks

Question 8

What are the non cytotoxic chemotherapy drug types that can be used

Answer 8

Hormones

Immunoglobulins, tyrosine kinase inhbitors

• EGFR
• target immune checkpoints
• can increase immune cell efficacy/increase immune surveillance

Question 9

What is neutropenic sepsis

• presentation
• prophylaxis
• management

Answer 9

7-14 days after chemo

• neutrophils U0.5x10 9 in anticancer treatment
• flulike (38C+, rigors, headache, aching muscles, cough, sore throat)
• dysuria

Prophylaxis - fluoroquinolone

Management -

• EMPIRICAL - piperacillin tazobactam
• can add G-ve cover

Question 10

What is tumour lysis syndrome

• pathophysiology
• etiology
• investigations
• management

Answer 10

Breakdown of tumour cells => release of K, PO4

• PO4 binds to Ca => CaPO4 crystals => AKI
• high K, low Ca => cardiac arrythmias
• nucleic acids => urate => urate crystals => AKI

Chemotherapy, esp in treatment of high grade lymphomas, leukemias
Spontaneous if tumour load high

High K, PO4, urate
Low Ca

Preventative
-allopurinol (prevent urate crystal formation)/rasburicase (breakdown urate crystals)

Question 11

Describe the function of immune checkpoint inhibitors

• function
• SE

Answer 11

Checkpoint inhibitors block Tcell immune surveillance (PDL1 found on cancer cells)
-reactivate, increase Tcell population to recognise and fight cancer cells

SE - all immune cells boosted => overactivity

• dry, itchy rashes
• N+V+D
• fatigue, tired
• pneumonitis => SOB, dry cough
• myocarditis, hepatitis