Principal Consultant, Radiation Oncology, BLK-Max Super Speciality Hospital, New Delhi
Series overview · 10 articles
Radiation Oncology Advances
August 28, 2026
Cancer has become one of the defining public health problems of the century. GLOBOCAN data put the 2022 global toll at nearly 20 million new cases and about 10 million cancer-related deaths, with roughly one in five people developing cancer in their lifetime and one in nine men and one in twelve women dying from it. By 2040, annual new cases are projected to reach 30 million, with deaths rising to 15.3 million. Radiotherapy is required by an estimated 50 to 70 percent of cancer patients at some point in their treatment, whether delivered with curative intent, as adjuvant therapy after surgery, or for palliation. Dr. Garima Singh, Principal Consultant in Radiation Oncology at BLK-Max Super Speciality Hospital in New Delhi, laid out this landscape and the technology reshaping it in a masterclass hosted by Jivo Healthcare and Max Healthcare on February 22, 2026.
The Core Trade-Off in Radiation Therapy
Every radiotherapy plan balances two competing forces: tumor control and normal tissue toxicity. Raising the dose to a tumor improves control but increases the risk of damaging surrounding healthy tissue; lowering the dose reduces toxicity but weakens control. The task, as Dr. Singh put it, is to deliver a precisely measured dose to a well-defined tumor volume while minimizing damage to the tissue around it, with the goal of eradicating the tumor while preserving quality of life and prolonging survival. Decades of technological advancement in radiation oncology have been aimed almost entirely at shifting this trade-off in the patient's favor: delivering more dose where it is needed and less everywhere else.
Where Radiotherapy Fits Across Cancer Types
Radiation plays a central role across most solid tumors. In head and neck cancer, early and locally advanced disease can be treated with radical or curative intent, and radiation is also used as adjuvant therapy after surgery. In prostate cancer, stereotactic body radiotherapy is used in early-stage disease, while hypofractionated regimens are common in locally advanced cases. Muscle-invasive bladder cancer has a well-established role for radiotherapy, as does cervical cancer at both early and locally advanced stages. In breast cancer, radiation is routine after breast-conserving surgery and is also used for palliation in metastatic disease. Lung, esophageal and anal canal cancers round out the list of tumors where radiotherapy is widely used, making it one of the backbones of cancer treatment alongside surgery and systemic therapy. Radiation also has an established role in a set of benign conditions, including acoustic neuroma, fibromatosis, aneurysmal bone cyst, trigeminal neuralgia, cavernoma and cavernous haemangiomas.
From X-Rays to Linear Accelerators
Radiotherapy's history stretches back further than most patients realize. Between 1895 and 1900, X-rays were already being used to treat a range of diseases, including skin cancers and even benign conditions such as eczema and lupus. This gave way to the orthovoltage era, using energies of roughly 50 to 200 kilovolts to reach deeper tumors. The megavoltage era followed, built around cobalt-60 units and linear accelerators: the first cervical cancer patient was treated with cobalt-60 at Victoria Hospital in 1951, and the first linear accelerator treatments took place around 1945 and 1946, delivering comparatively low doses through machines that were, by today's standards, rudimentary.
The Modern Toolkit
External beam radiotherapy has progressed from conventional delivery through three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), four-dimensional radiotherapy, adaptive radiotherapy, stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). Each step added a layer of precision. IMRT, built around the multi-leaf collimator that shapes a beam into hundreds of small beamlets, allowed radiation oncologists to deliver a high dose to an irregularly shaped tumor while sparing organs sitting right next to it; a phase III trial published in The Lancet Oncology in 2011 found that IMRT cut the incidence of xerostomia, a common late side effect, by half compared with conformal radiotherapy in head and neck cancer, largely through parotid gland sparing. IGRT layered real-time imaging onto IMRT to verify patient positioning during treatment itself. Tomotherapy combined the two with a 6 MV linear accelerator mounted on a ring gantry, useful for long treatment fields such as total body irradiation and craniospinal irradiation. Stereotactic techniques took precision further still, delivering very high doses in a handful of sessions to intracranial and, in the case of SBRT, extracranial targets. Proton therapy pushed the physics itself in the patient's favor, depositing most of its energy at a defined depth (the Bragg peak) with minimal exit dose beyond the tumor. These technologies are covered site by site later in this series.
Fewer Fractions, Comparable Outcomes
Alongside machine precision, dose fractionation has been rewritten. Breast cancer treatment has moved from 25 fractions in earlier decades to 15 fractions following hypofractionation trials, and now to 5 fractions in selected patients under the FAST-Forward protocol. Guidelines including the UK's START trials, ESTRO and NCCN now support hypofractionation across a widening range of clinical scenarios, and prostate cancer, with its low alpha-beta ratio of roughly 1.2 to 1.5, responds particularly well to larger doses per fraction. The practical effect has been to roughly halve the treatment courses for breast and prostate cancer over the past two decades, which matters as much for capacity as for convenience.
Access Remains the Binding Constraint
Technology has not yet solved radiotherapy's biggest problem: at least 25 percent of patients who need radiotherapy do not receive it. Demand is projected to keep rising, and in many regions treatment capacity has not kept pace. If every patient who needed radiotherapy by 2035 could access it, close to one million additional lives could be saved every year worldwide. Shorter, hypofractionated courses help by allowing more patients to be treated within existing infrastructure, but expanding access to radiotherapy remains, in Dr. Singh's framing, one of the more consequential unmet opportunities in global oncology.
What This Series Covers
The rest of this series works through the specific technologies and clinical decisions behind this overview: intensity-modulated and image-guided radiotherapy in practice, tomotherapy and dose escalation in prostate cancer, stereotactic radiosurgery and SBRT, proton therapy and pediatric radiotherapy, cardiac-sparing and motion-management techniques, the hypofractionation trend in detail, brachytherapy's role in gynecological cancer, a staging-based framework for cervical cancer, and a practical, site-by-site guide to when radiotherapy is the right call.
This guide is based on a live Jivo Masterclass — Dr. Garima Singh taught doctors across Africa on February 22, 2026.
Watch the full recording, or read the guide above.
FROM THE LIVE Q&A
Dr. Ivan Ipavu, Uganda
What are the complications of stereotactic radiotherapy (SRT/SRS), and what is the prognosis?
Dr. Garima Singh
It depends heavily on where the tumour sits. In fractionated radiosurgery for brain tumours, the incidence of radiation necrosis runs below 10 percent, and brain edema is another recognised complication. Risk rises when the target is near a critical structure such as the motor cortex or brainstem; robust dosing data for the motor cortex are limited, but the working figure for a single SRS session is around 15 Gy to that structure. With fractionated SRT or SRS, clinicians have to be especially vigilant about the proximity of organs at risk during planning. Done with that vigilance, SRS can be delivered safely to metastatic brain lesions with minimal complications, though it demands real expertise and careful dose painting.
Frequently Asked Questions
What has been your experience treating pediatric cancer patients?▼
I have treated around ten pediatric patients from Ethiopia specifically, as part of a broader pediatric caseload. Pediatric malignancy needs to be treated very carefully. In medulloblastoma, for example, craniospinal irradiation planning has to be extremely precise to prevent radiation-related toxicity. Because survival in cancers like ependymoma and medulloblastoma is often good, the most important concern becomes preventing secondary malignancy later in life, which means paying close attention to low-dose spillage, or integral dose, across the whole treatment field. For pediatric cases needing long treatment fields, we generally use tomotherapy, and we get very good outcomes.
When is radiotherapy a viable treatment option for a patient, and when is it not?▼
It depends on the site and the stage. In early-stage head and neck cancer, surgery alone can be sufficient, but high-risk features on post-surgical pathology can still require adjuvant radiotherapy. In locally advanced disease, radiotherapy is generally needed as part of definitive treatment. In stage IV disease, radiotherapy is mostly palliative: relieving pain, bleeding, cord compression or hemoptysis. More than 50 to 60 percent of patients need radiotherapy at some point, whether as radical treatment, adjuvant therapy or palliation, and we rely on a multidisciplinary tumour board to decide the exact timing for each patient.
What is the guiding principle for when to integrate chemotherapy with radiotherapy, versus using either alone?▼
We follow international guidelines. Using cervical cancer as an example: stage IA, IB and IIA disease is treated with surgery first. Adjuvant treatment then depends on the Sedlis and Peters criteria: positive margins or positive nodes call for concurrent chemoradiation; deep stromal invasion beyond one-third, a tumour over 4 centimetres, or lymphovascular space invasion, without positive margins or nodes, call for radiation alone; if none of those features are present, no adjuvant treatment is needed and the patient goes to follow-up. Locally advanced disease, stage IB3 to IVA, needs concurrent chemoradiation. Stage IVB generally starts with chemotherapy, though a bulky tumour or high nodal burden may call for six weeks of neoadjuvant chemotherapy before concurrent chemoradiation. Every site, endometrium, lung, breast, has its own guideline, and we make these calls through tumour board discussion.
Does imaging or histopathological cell type weigh more heavily in this decision?▼
They are complementary, not competing. Staging starts with clinical examination: if the tumour looks confined to the cervix, with no fornix or parametrial involvement and a size under 4 centimetres, surgery looks feasible on clinical grounds. MRI is then used specifically to confirm there is no parametrial invasion, which gives us a clinico-radiological diagnosis. Only after surgery does histopathology decide whether adjuvant treatment is needed. This stepwise approach, clinical exam, then imaging, then surgery, then histopathology, is important because operating on an advanced or bulky tumour without confirming operability first raises the risk of a positive margin, which then commits the patient to more aggressive treatment than necessary.
Is there a role for radioactive bead implants (brachytherapy) in this therapy?▼
Yes, that is brachytherapy. Historically, cervical cancer brachytherapy used preloaded sources, meaning the source had to be implanted directly. Technology has evolved to after-loading systems: the applicator, such as the Fletcher-Suit system, is placed first, and the radioactive source is then transferred into the tandem remotely through the treatment machine. That shift from preloading to after-loading has improved safety for patients and staff.
How many new cancer cases were recorded worldwide in 2022?▼
GLOBOCAN data put the 2022 global toll at nearly 20 million new cases and about 10 million cancer-related deaths. By 2040, annual new cases are projected to reach 30 million, with deaths rising to 15.3 million.
What is the fundamental trade-off in radiation therapy planning?▼
Every radiotherapy plan balances tumor control against normal tissue toxicity. Raising the dose to a tumor improves control but increases the risk of damaging surrounding healthy tissue, while lowering the dose reduces toxicity but weakens control.
When was cobalt-60 first used to treat cancer patients?▼
The first cervical cancer patient was treated with cobalt-60 at Victoria Hospital in 1951, marking the start of the megavoltage era. The first linear accelerator treatments took place around 1945 and 1946.
What impact did intensity-modulated radiotherapy have on side effects in head and neck cancer?▼
A phase III trial published in The Lancet Oncology in 2011 found that IMRT cut the incidence of xerostomia, a common late side effect, by half compared with conformal radiotherapy, largely through parotid gland sparing.
What technologies make up the modern external beam radiotherapy toolkit?▼
External beam radiotherapy has progressed through three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, image-guided radiotherapy, four-dimensional radiotherapy, adaptive radiotherapy, stereotactic radiosurgery and stereotactic body radiotherapy, with each step adding a further layer of precision.
In This Series: Radiation Oncology - Advances & Latest Trends
- 1.Radiation Oncology Advances
- 2.IMRT and IGRT: The Foundations of Precision Radiotherapy
- 3.Tomotherapy and Dose Escalation in Prostate Cancer
- 4.Stereotactic Radiosurgery and SBRT: High-Precision Treatment for Brain and Body
- 5.Proton Therapy, Pediatric Radiotherapy and Emerging Modalities
- 6.Cardiac Sparing and Motion Management in Radiotherapy
- 7.Hypofractionation and the Global Access Gap in Radiotherapy
- 8.Brachytherapy in Gynecological Cancer: From Cervix to Endometrium
- 9.Cervical Cancer: A Staging-Based Treatment Framework
- 10.When Is Radiotherapy the Right Choice? A Site-by-Site Decision Guide