Radiotherapy uses precisely directed high-energy radiation to damage and destroy cancer cells. One of the most important tools in cancer care — it can be curative, preventive, or used to relieve symptoms — always planned in coordination with surgery for the best outcome.
Radiotherapy uses high-energy rays or particles — X-rays, gamma rays, electron beams, or protons — to damage the DNA of cancer cells, preventing them from dividing and causing them to die. Unlike surgery, which removes the tumour physically, radiotherapy destroys cancer cells in place, often preserving the surrounding organ.
Cancer cells are less able to repair radiation damage than normal cells — this is the fundamental principle that makes radiotherapy effective. Treatment is precisely planned using 3D imaging to deliver maximum dose to the tumour while minimising exposure to healthy surrounding tissue.
Modern radiotherapy is highly sophisticated. Techniques like IMRT, IGRT, and SBRT allow sub-millimetre precision. It may be used as the sole treatment, combined with chemotherapy, before surgery to downstage tumours, or after surgery to eradicate residual disease.
The decision of whether to give radiotherapy before or after surgery — or instead of surgery — is one of the most important in oncology. For rectal cancer, neoadjuvant chemoradiation can downstage the tumour significantly. For early laryngeal cancer, radiotherapy may preserve the voice entirely.
I work closely with radiation oncologists to ensure the sequencing is correct for each patient — and that surgical margins, clips, and anatomical details are communicated precisely to allow optimal RT planning.
— Dr. Vinod T. Gore, MBBS MS FAIS FIAGES FARIS (Edin)Radiotherapy is used in four distinct settings. The goal — whether cure, downstaging, prevention, or symptom control — determines timing, dose, and technique.
Radiotherapy as the primary curative treatment, without surgery — used when surgery would cause unacceptable functional loss or the tumour is highly radiation-sensitive.
Larynx (voice preservation), early prostate, cervical, anal, head & neck cancers.
Curative IntentGiven before surgery to shrink the tumour, enabling more complete resection with clear margins and reducing the risk of local recurrence.
Rectal cancer, oesophageal cancer, soft tissue sarcoma, locally advanced breast cancer.
Pre-operativeGiven after surgery to destroy microscopic residual cancer cells at the surgical site — reducing local recurrence when margins are close or nodes are involved.
Breast, head & neck, brain, endometrial, lung, rectal cancers post-resection.
Post-operativeUsed to relieve symptoms in advanced cancer — effective for pain from bone metastases, spinal cord compression, bleeding, and airway obstruction.
Bone mets, brain mets, SVC obstruction, haemoptysis.
Symptom ReliefModern radiotherapy encompasses a range of sophisticated techniques — each chosen based on tumour location, size, and proximity to critical structures.
| Technique | How It Works | Key Advantage | Common Use |
|---|---|---|---|
| EBRT Standard | External beam delivers X-rays from a linear accelerator, targeting from multiple angles | Widely available; suitable for most solid tumours | BreastProstateLungColorectal |
| IMRT Precision | Modulates dose intensity across the beam — sculpts precise dose around complex tumour shapes | Spares critical organs near tumour | Head & NeckProstateGynaecological |
| IGRT Image-Guided | Real-time imaging before each session accounts for daily tumour and organ movement | Accounts for daily variation in organ position | ProstateLungLiverAbdomen |
| SBRT / SABR High Dose | Very high doses in 3–5 fractions with extreme precision — ablative in intent | Short course; highly effective for small discrete tumours | Early LungLiver metsSpine mets |
| SRS / Gamma Knife Brain | Single high-dose radiation pinpoint targeted at brain lesions — no surgery required | Non-invasive treatment of brain tumours and metastases | Brain metsMeningioma |
| Brachytherapy Internal | Radioactive seeds or wires placed inside or adjacent to the tumour — high local dose with minimal scatter | Concentrated local dose; minimal surrounding tissue impact | CervixProstateBreastOesophagus |
| IORT Intraoperative | Radiation delivered directly to tumour bed during surgery after tumour removal | Direct access to tumour bed; shields normal structures | BreastRectalSarcomaPancreas |
Radiotherapy is a carefully engineered process — involving imaging, dosimetry, and precision delivery over several weeks.
The patient undergoes a dedicated planning CT in the treatment position. Immobilisation devices (masks, moulds) are made to ensure identical positioning every session.
Done 1–2 weeks before treatment beginsRadiation oncologists and physicists define tumour volumes (GTV, CTV) and plan dose distribution — ensuring full tumour dose while protecting organs at risk.
Surgical clips placed by Dr. Gore guide precise target delineationRadiation is given daily (Mon–Fri) in small doses called fractions, typically over 3–7 weeks. Each session lasts 10–20 minutes. Palliative RT may be just 1–5 sessions.
Fractionation allows normal cells to recover between dosesSide effects are largely site-specific — determined by the area being treated, not the radiation itself. Most acute effects resolve after treatment ends.
The most universal side effect — builds over the course of treatment and resolves gradually afterwards. Rest and light activity both help.
Redness, dryness, or peeling in the treated area — similar to sunburn. Managed with moisturisers and dressings. Usually heals within weeks post-treatment.
Hair loss occurs only in the specific area being irradiated — not throughout the body. Usually reversible, though high doses can cause permanent localised loss.
Inflammation and ulceration of the mouth and throat lining — painful but managed with mouthwashes and pain relief. Resolves after treatment.
Reduced saliva from salivary gland irradiation. IMRT spares parotid glands where possible. Saliva substitutes and pilocarpine help significantly.
Dysphagia from oropharyngeal inflammation. NG or PEG tube feeding may be needed temporarily. Swallowing therapy aids recovery.
Lung inflammation — presents as cough and breathlessness 1–3 months post-RT. Managed with corticosteroids. Modern planning minimises lung dose.
Left-sided breast RT carries a small cardiac risk. Deep Inspiration Breath Hold (DIBH) technique reduces heart dose significantly in modern centres.
Temporary swelling, tenderness and skin changes during treatment. Late effects — firmness or mild shrinkage — are generally minor with modern RT.
Diarrhoea, urgency and cramping from bowel mucosal irritation. Dietary modification and antidiarrhoeals help. Resolves after treatment.
Frequency, urgency, and mild burning from bladder wall irritation. Drinking plenty of fluids helps. Usually settles after treatment ends.
Pelvic RT can affect ovarian function and fertility. Sperm banking, embryo freezing, and ovarian transposition are options to discuss before starting treatment.
Late effects (months to years after RT) include fibrosis, lymphoedema, and rare secondary malignancy risk. Modern techniques like IMRT and IGRT have substantially reduced late toxicity. All risks are discussed before treatment begins.
A surgical oncologist plays a critical upstream role in radiotherapy — long before the first dose is delivered. Decisions made in the operating theatre directly determine the quality of RT planning.
If you have been advised radiotherapy or want to understand how it fits into your treatment plan, book a consultation with Dr. Gore for a surgical oncologist's complete perspective.