Radiotherapy

Weston Park Hospital

Helen Simpson

Trainee Consultant Radiographer

Oct 2019

What is Radiotherapy

Radiotherapy is the use of x-rays and electro-magnetic radiation to treat disease.

Major modality in the management of cancer alongside surgery and

chemotherapy 40% of cured patients have received RT as part of treatment At WPH 4000 new patients treated 6500 patient attendances Energy much higher than when used to diagnose illness

Diagnostic – up to 150 kV Radiotherapy – up to 10 mV

The Origins of Radiotherapy

X-rays were discovered by Roentgen in 1895

The development of the x-ray tube rapidly led to clinical applications, first as a diagnostic tool and later for therapy

The Origins of Radiotherapy

In 1898 Marie and Pierre Curie discovered Radium and Polonium

This resulted in the use of radioactive materials for cancer treatment

First Radiotherapy Treatment

Emil Grubbe 1875 – 1960 First to use X-rays for treatment of Cancer 1896 Treated patient with recurrent carcinoma of

the Breast Due to radiation exposure himself had 90 operations to remove cancers

Radiotherapy: then and now

Late 1940’s 2018

We can use radiotherapy with the aim to:

Cure the cancer (radical radiotherapy)

Reduce Risk of recurrence (Adjuvant)

Control symptoms caused by the cancer to improve quality of life (palliative radiotherapy)

Aim of Radiotherapy

How does Radiotherapy work? Radiotherapy causes

biochemical changes within the cells.

During mitosis DNA is damaged Radiobiological damage

affects repair, redistribution, repopulation and re oxygenation.

If cells are hit by radiation whilst they are dividing they will be damaged and find it much more difficult to repair themselves.

How does Radiotherapy work?

Cancer cells multiply and divide much more quickly than normal cells

Normal cells in the treatment area are also affected by the x-rays but they recover quickly

Deliver enough radiation to kill the cancer cells whilst allowing normal cells to repair themselves

Breast Radiotherapy

Radiotherapy is a standard treatment option for most women following WLE with invasive breast cancer Post-mastectomy radiotherapy is given to node-positive (macro metastases) invasive breast cancer or involved resection margins. Radiotherapy is also given for intermediate and high grade DCIS ( Ductal Carcinoma in Situ). Adjuvant – kills residual microscopic disease after surgery and/or chemotherapy to reduce the risk of local regional recurrences. Nodal Radiotherapy – 4 or more positive lymph nodes or 1-3 with poor prognostic factors Radiotherapy after neo- adjuvant chemotherapy and surgery

Breast Radiotherapy

Localisation

Radiotherapy planning scan in the treatment position

CT scanner provides cross sectional image slices to enable visualisation of the target area to be irradiated – size shape volume

Patient marking - tattooing

Different to a diagnostic scanner – larger aperture couch top identical to treatment units

Radiotherapy Planning

Radiotherapy Scanner

Essential for accurate reproducibility

Usually 3 max

Permanent

Tattooing

Pre- treatment pathway

CT scan appointment

Consented for RT

Dr approves fields

placement outlines PTV & organs at risk

A computerised plan produced

represents dose distribution through the

volume

Plan checked by physicists &

Doctor prescribes dose

Treatment inputted and prepared on

computer system

Radiotherapy begins

Radiographers place radiation

fields on CT

From CT scan to treatment

takes 7-10days

Radiotherapy Planning

Radiotherapy Planning

External beam Radiotherapy

Treatment machines are called Linear Accelerators

High energy x-rays

6-10 Mv

Breast Radiotherapy Treatment

Tangents – glancing fields

Daily treatment

Monday to Friday

15 daily treatments to the breast tissue +/- nodes

If having a boost to the tumour bed additional 8 treatments

Usually treated on same linear accelerator

Team of 4 Radiographers

Do not feel anything, see anything

Deep Inspiration Breath hold

Deep Inspiration Breath hold

Aim to reduce cardiac toxicity in breast radiotherapy Improves reproducibility Increases time to plan and deliver treatment

Radiotherapy Boost

Nice guidelines 16Gy in 8 treatments following whole breast RT Age under 50 (omitted 40-50 with low risk local recurrence) Over 50 – high risk of local recurrence (grade 3, extensive intra ductal component. Tumour at inked margin. Less than 1mm from invasive tumour).

Radiotherapy Boost

Implants

Seroma’s

Affect the external contour of the patient Dose implications Delay to start radiotherapy Implications of repeated drainage

Radiotherapy to Nodes

Supraclavicular Fossa 4 or more involved axillary lymph nodes 1 to 3 positive lymph nodes if other poor prognostic factors (for example, T3 and/or grade 3) and good performance status Axilla/SCF As an alternative to Axillary Node Dissection (AND) after positive Sentinel Node Biopsy (not for micro metastasis) Not routinely after AND, unless high risk of axillary recurrence Internal Mammary Chain Involved internal mammary node Consider in high risk node-positive (macro metastases) T4 N2-3 N1 with medial/central location

Radiotherapy to Nodes

Intensity Modulated Radiotherapy

Conform (shape) the beam around the treatment area using Multileaf Collimators (MLCs).

IMRT

IGRT(Image guided radiotherapy)

Modern Radiotherapy Linear Accelerators have integral imaging facilities that allow us to image the patients ‘real time’ whilst they are in the treatment position and before we deliver any treatment. At the treatment console we can compare the planning images directly with those captured by the LA to optimise treatment accuracy.

Side effects of Radiotherapy Skin reaction – Radiation Dermatitis. Only in area treated – 10-14days after first exposure (the time

it takes for the damage to the basal layer of the skin to migrate to the skin surface).

Activation of the inflammatory response Dependent on area treated Build up as treatment progresses peak reaction 7-10

days after treatment finishes (time taken for basal cells damaged to reach the skin surface)

erythema Dry/ moist desquamation – when basal layer

can’t produce enough new cells Hair loss if any in treated area fatigue

Breast reactions

Non perfumed moisturising cream e.g. E45, diprobase, aveeno, aloe vera – from before radiotherapy begins.

1% hydrocortisone cream - to itchy skin BD

Flamazine / intrasite gel – moist desquamation

Medication for Side effects

Toxicity

Acute Radiation Toxicity – Rarely life threatening Rapidly proliferating tissues Reversible Dose limiting in some contexts

Late Radiation Toxicity - Can be severe but well understood due to long history Slow/ non-proliferating tissues Irreversible Nearly always dose limiting

Factors affecting Skin effects

Intrinsic factors Age – older skin slower epidermal cycle Nutrition - undernourished Smoking/Alcohol – decrease capillary blood flow impairs healing Co-morbidities – diabetes and steroids UV exposure/ ethnic origin – BME patient Obesity – extra skin folds Infection – bacterial or fungal can slow healing

Extrinsic factors Radiotherapy – dose, size, bolus Energy of radiotherapy – higher doses less damage (skin sparing effect) Radio sensitises - some chemotherapy cisplatin, 5-Fu Chemical / thermal / mechanical – metal in creams, irritants, extremes of temperature hot water bottles , ice packs, clothes that rub.

Long terms side effects

Skin pigmentation changes within the treated area Telangiectasia – thread veins Breast oedema Breast shrinkage Nodal areas Arm lymphoedema Shoulder stiffness Rare Lung fibrosis Rib fractures Cardiac damage Second cancer Implants – capsule formation, rupture, fat necrosis.

Evidence for future practice in radiotherapy and influence cancer treatment regimes

Improves patient choice

Improving survival and quality of life of our patients

Changes in practice- we are where we are today due to previous research

Radiotherapy Research Why is it important?

Radiotherapy Research

WPH completed the feasibility study 2019 – next will be multi centre study

Future Breast Radiotherapy

Radiotherapy Team

Consultant Clinical Oncologists Consultant Radiographer ACP Specialist Radiographer Radiographers Planning Technicians Physicists Information and support Radiographers

Radiotherapy open evenings- monthly

Information booklets

Photo books in DGH’s

Open evenings for all health care professionals

Radiotherapy awareness events

Initiatives to Improve the Radiotherapy Journey

Information and Support during Radiotherapy

On treatment review

All patients monitored on a daily basis by Radiographers on treatment machine

All patients having 5 or more treatments are reviewed weekly.

Review can be by member of the medical team or by specially trained radiographers- ACP.

Radiographers can give certain medication under a PGD, or as independent prescribers.

Thank you