TomoTherapy (helical radiotherapy) in Turkey

TomoTherapy is a brand of helical, image-guided, intensity-modulated radiotherapy. Conventional linear accelerators deliver radiation from a rotating arm that stops at chosen angles or sweeps in arcs; TomoTherapy delivers it continuously from all angles around a ring while you move through it, the way a CT scanner acquires images. A binary collimator opens and closes its leaves many times per rotation to shape the intensity, and the daily image is taken with the treatment beam itself at low energy.

The practical differences follow from the geometry. Because the couch moves through the ring, there is no limit on the length of the target, so the whole spine and brain, the whole bone marrow, or several separate tumours can be treated in one plan without joining fields together. Because the dose comes from every angle, sparing of nearby organs is generally good, at the cost of spreading a low dose through a larger volume of normal tissue. Because the arm cannot tilt, beams that come from outside the plane of the ring, which some brain and head and neck plans use, are not available. Sessions can also take longer than on an arc-based machine. None of these is a reason to seek out or avoid the machine on its own; they are reasons why a radiation oncologist chooses one platform over another for a particular case.

• Where it has a real advantage

  Long or irregular targets: irradiation of the whole brain and spine, total marrow irradiation before a transplant, extensive head and neck disease, several tumours treated in one plan.

• Where it is one good option among several

  Prostate, breast, lung, gynaecological and rectal cancers, where arc-based intensity-modulated radiotherapy on a conventional accelerator gives comparable plans.

• Where other machines are usually preferred

  Very high-dose stereotactic treatments of small targets and plans that need beams from outside the ring's plane; those usually go to an arc-based accelerator, CyberKnife or Gamma Knife.

• Where the machine is beside the point

  Any case where the question is still whether radiotherapy is indicated at all, or where the timing against surgery and chemotherapy has not been decided by a tumour board.

The generic questions about a course of radiotherapy abroad, including techniques, side effects by body site and how a course is planned, are covered on the radiation therapy page. For focused single-session or short-course treatments see CyberKnife; for the wider picture of cancer care see oncology in Turkey.

• Side effects belong to the site, not the machine. Fatigue is near universal. Skin reaction, mouth and throat soreness, swallowing difficulty, nausea, diarrhoea, bladder irritation and hair loss depend on what is being treated, and TomoTherapy does not remove them; good planning reduces them.
• Low-dose bath. Helical delivery spreads a low dose through a larger volume of normal tissue than some other techniques. The clinical significance is debated, and it is a reason for careful planning in younger patients.
• Late effects. Fibrosis, dry mouth, bowel and bladder changes, fertility loss, heart and lung changes and a small long-term risk of a second cancer follow from the dose to normal tissue, whatever machine delivers it, and appear months to years later.
• Geometric miss and machine error. Rare, but real; the defence is daily imaging, a mask that fits, a physicist's quality assurance programme and an oncologist who reviews the images. Ask about all four.
• Interruptions. A course that stops for illness, travel or money loses effect; the schedule matters more than most people expect. Plan the stay for the whole course plus margin.
• Emergencies far from home. Chemoradiation can cause dangerous drops in blood counts, infection and dehydration; the hospital treating you must be the one you can reach at night.
• Follow-up in two countries. Late effects and recurrence are picked up by follow-up scans; if the handover is not arranged before you travel, the treatment is unfinished.

• Choose the department, not the unit. Ask for the radiation oncologists, the medical physicists and the tumour board; a machine without a strong physics team is a liability.
• Ask what else the department has. A department that also runs arc-based accelerators and stereotactic systems can choose the right platform for you; one with only TomoTherapy will use TomoTherapy.
• Insist on a written plan before you fly. Intent, target, dose, sessions, technique, concurrent chemotherapy and who is responsible.
• Budget for the whole stay. Accommodation near the hospital for the full course, a companion, and a margin for delays.
• Fix the handover in advance. Treatment summary, plan images and scan schedule to your oncologist at home, in a format they have agreed to accept.
• Keep your own copies. Histology, staging, plan and treatment summary; you will need them for years.

• European Society for Radiotherapy and Oncology, patient information on radiotherapy techniques including intensity-modulated and image-guided radiotherapy.
• National Cancer Institute, radiation therapy to treat cancer: types, side effects and what to expect.
• American Society for Radiation Oncology, patient guidance on external beam radiotherapy and questions to ask before treatment.
• Accuray, TomoTherapy platform technical description and indications for use.
• Republic of Türkiye Ministry of Health, register of facilities authorised for international health tourism and radiation oncology licensing.