Rectal Cancer Radiation Therapy

Radiation given before the operation halves the chance of rectal cancer coming back in the pelvis. In some patients it removes the need for an operation at all.

A colonoscopy has found a tumor in the rectum. The biopsy confirms cancer, and the MRI report describes how far it has grown through the wall. For most tumors that reach beyond the wall or into nearby lymph nodes, treatment begins with radiation rather than with the operation, and that order was decided by a trial. In the German trial that settled it, published in the New England Journal of Medicine in 2004, giving chemoradiation before surgery instead of after cut the chance of the cancer returning in the pelvis from 13 percent to 6 percent at five years, with fewer serious side effects. Two things have changed since. Chemotherapy has moved in front of the operation as well, and half of the patients whose tumor disappears completely on treatment can now keep their rectum under close watch. This page walks through those choices, the one-week and five-week courses, the side effects that matter for years, and how to plan the months in Istanbul.

Rectal Cancer Radiation Therapy is treated as a separate subject from colon cancer because of where the rectum sits. The last fifteen centimeters of the bowel lie inside the bony pelvis, wrapped in a fatty envelope and pressed against the bladder, the prostate or the uterus, the sacrum and, at the bottom, the muscles that keep you continent. No wide margin of loose tissue exists for a surgeon to take.

Colon cancer rarely comes back where it started. Cancer of the rectum used to, in a quarter of patients or more, and a recurrence in the pelvis is painful and hard to treat. Radiation exists to stop that. A second purpose came later. A tumor that shrinks before the operation comes out with clear margins more often, and a tumor sitting on the sphincter sometimes comes out without taking the sphincter with it.

A pelvic MRI decides. It shows how deep the tumor has grown, whether lymph nodes look involved, how close the tumor comes to the membrane around the rectum called the mesorectal fascia, and whether tumor has entered veins outside the wall.

The review may ask for the MRI to be repeated when it was done without a dedicated rectal protocol. The stage drives everything that follows. A poor scan produces a poor plan.

For years, radiation was given after the operation to patients whose pathology looked worrying. The German Rectal Cancer Study Group tested the opposite order in 823 patients with tumors through the wall or with involved nodes.

823 patients. Same drugs, same dose, different order. Pelvic recurrence 6 percent against 13 percent at five years. Serious acute side effects 27 against 40 percent. Serious late effects 14 against 24 percent.

That result is the foundation of everything on this page. Recurrence in the pelvis halved. Side effects fell. Survival came out the same in both groups, 74 and 76 percent at five years, because what kills most rectal cancer patients is spread to the liver and lungs, and radiation to the pelvis has no reach there.

Two reasons explain the difference, and both are physical. Before surgery the tissues still have their blood supply, so oxygen reaches the tumor and radiation works better. The bowel that an operation pulls down into the pelvis has not yet moved into the beam.

Two schedules exist.

They resemble each other more in effect than in daily life, since one is over in a week and the other fills five, and the choice between them shapes the whole calendar of a trip abroad.

The Stockholm III trial, reported in the Lancet Oncology in 2017, put the two head to head in 840 patients and found local recurrence equally low with either. It also found that waiting four to eight weeks after the short course lowered surgical complications from 53 percent to 41 percent, compared with operating within a week. Waiting is now the standard.

Which one for you

A tumor that must shrink to come out with clear margins, or one sitting close to the sphincter where shrinkage might save it, points toward the long course or toward total neoadjuvant therapy. A patient who cannot spend five weeks near a hospital, or who is frail, points toward the short course. Neither counts as second best.

Radiation controls the pelvis. It does nothing for cancer cells that have already reached the liver or lungs, and in the years after the German trial distant spread became the main reason patients died. Chemotherapy given after surgery was supposed to deal with that, and many patients never received it, because recovery from a rectal operation takes months.

So the chemotherapy moved forward.

All of it. Total neoadjuvant therapy, TNT, means giving radiation and the full course of chemotherapy before the operation, in one of two orders, and it has become the default for any tumor that the MRI marks as high risk.

• RAPIDO, Lancet Oncology 2021. 912 patients with high-risk tumors. One week of short-course radiation, then 18 weeks of chemotherapy, then surgery, against the older sequence of long-course chemoradiation, surgery and optional chemotherapy afterwards. Disease-related treatment failure at three years fell from 30.4 percent to 23.7 percent, while serious diarrhea during treatment rose from 9 percent to 18 percent.
• PRODIGE 23, Lancet Oncology 2021. 461 patients in France with tumors through the wall. Twelve weeks of FOLFIRINOX chemotherapy, then long-course chemoradiation, then surgery, then a shorter course of chemotherapy afterwards, against chemoradiation and surgery alone. Disease-free survival at three years, 76 percent against 69 percent. Nerve damage from the chemotherapy was less in the new sequence, because less of it was given after the operation.

Both trials changed guidelines. For a high-risk tumor on MRI, treatment now runs for five to six months before the surgeon sees the patient, and for a fit person that is the sequence we propose. The price is paid in the chemotherapy itself. Tiredness. A blood count that has to be checked before every cycle. Numb fingertips that oxaliplatin leaves in some people for months.

A rectal operation costs something even when it goes well. A low tumor means a permanent colostomy, and a tumor a little higher means a join near the anus and bowel function that never fully returns. When months of radiation and chemotherapy make a tumor disappear on examination, on MRI and on endoscopy, the question arises whether the operation is still needed.

The OPRA trial, published in the Journal of Clinical Oncology in 2022, answered it prospectively in 324 patients given total neoadjuvant therapy. Those with a complete response were offered watching in place of surgery. Examination, endoscopy and MRI every few months. Three years later, 53 percent of the patients in the group that received chemoradiation first and chemotherapy afterwards still had their rectum, and 41 percent in the group that received chemotherapy first. Disease-free survival, 76 percent, matched what surgery would have been expected to give. Tumors that regrew were operated on, with results as good as immediate surgery.

If keeping the rectum matters to you, say so in the first message. It changes which sequence is chosen, since chemoradiation first and chemotherapy after gave more organ preservation in OPRA, and it changes how the follow-up is arranged between Istanbul and home.

Rectal radiotherapy has a routine, and once you know it the weeks pass more easily.

1. Position. Face down on a board with a cutout for the belly, so that the small bowel falls forward and out of the beam, or on your back where lying prone is impossible.
2. Bladder. A full bladder pushes more bowel away. You drink a set amount of water at a set time before the planning scan and before every session, and the same amount each day.
3. Planning CT and target. Small tattoo dots mark the skin. The target covers the tumor, the whole rectum with its fatty envelope, and the lymph node regions along the pelvic side walls up to the point where the rectal vessels branch.
4. Shaping the dose. Intensity modulated beams bend the high-dose region around the bladder, the small bowel, the hip joints and, in men, the bulb of the penis.
5. The session. Ten to fifteen minutes, with a cone-beam CT taken first to confirm the position and the bladder filling. Nothing is felt.

Radiotherapy at Biruni Hospital is delivered on an Elekta Versa HD linear accelerator. Planning takes five to seven working days from the scan to the first session.

Radiation to the pelvis is felt in the bowel, the bladder and the skin during treatment, and in bowel and sexual function for years afterwards. Both halves belong on the same page.

The German trial counted serious long-term effects at 14 percent after preoperative treatment. Beam shaping and the prone position were introduced to bring that figure down. Ask about bowel function before consenting. Of everything on the list, it is the one patients say nobody warned them of.

Total mesorectal excision, TME, is the operation. The surgeon removes the rectum together with its fatty envelope in one intact piece, because tumor deposits hide in that fat, and the quality of that piece, graded by the pathologist, predicts recurrence as strongly as anything else.

A permanent colostomy depends on two measurements. The distance between the bottom of the tumor and the sphincter, and how much the tumor shrank. A join low in the pelvis is protected for a few months by a temporary ileostomy, a loop of small bowel brought out on the right side of the belly, which a second, smaller operation closes once the join has healed.

Surgery, radiation and chemotherapy are all delivered at Biruni Hospital on one site, so the same colorectal surgeon who reviewed your first MRI examines you after treatment and performs the operation, or continues to watch.

Treatment for this cancer is measured in months, and the calendar depends on which sequence is chosen.

Three rules hold across every sequence.

• Chemotherapy between radiation and surgery can be given by an oncologist at home on the protocol we write, and many patients choose that.
• Radiation itself sets no limit on flying.
• After the operation the surgeon sets the date, around two weeks, once you are eating, walking and managing any stoma with confidence.

No price appears on this page. A rectal cancer quote is three quotes stacked, and the stack differs for every patient. Radiation forms the smallest of the three when the course is short and a larger one over five weeks, with planning, sessions and daily image guidance as its lines. Chemotherapy follows the drug, the number of cycles and body surface area, and FOLFIRINOX costs several times what capecitabine does. Surgery carries the operating time, the days in hospital, the stapling devices, a stoma kit, and the second operation to close a temporary ileostomy months later. Published packages from Turkish hospitals and medical travel agencies list radiotherapy, chemotherapy cycles and colorectal surgery separately, each covering consultation, the procedure, hospital days where planned, an interpreter and transfers, and leaving out flights, insurance, accommodation, stoma supplies at home and treatment of any complication.

A quote you can read states the sequence it assumes, the number of chemotherapy cycles, whether the ileostomy closure is inside the figure, and what happens if watch and wait replaces surgery. The figure follows the free review of your MRI.

Biruni Hospital gives every international patient one coordinator from the first message to discharge, reachable on the same WhatsApp number after you have gone home. The international patients team works in English, Arabic, French, Russian, Serbian, Romanian and Spanish and arranges interpreters for other languages, which for this diagnosis matters at three points, the consent discussion on stoma and sexual function, the weekly review during radiation, and the conversation after restaging where surgery or watching is decided.

Bring an adult companion for the weeks of radiation if you can, and certainly for the operation, since the first days with a stoma are easier with someone else in the room. The international patients office books accommodation for both of you, close to the hospital, together with airport transfers and the daily car, and it stays in touch with whoever is at home during the months of chemotherapy between visits. For a visa it issues an appointment confirmation and an invitation letter naming the hospital and the treating doctor, ten days or so before travel. Rooms have a companion bed. The kitchen prepares halal, vegetarian and diabetic meals and follows the low-fiber diet radiation calls for. A prayer room is on site. A female physician is arranged where the rota allows, for anyone who requests one in the first message.

Once you get back home, the handover file goes to your oncologist and, if you are being watched instead of operated on, to a colorectal surgeon or gastroenterologist who will examine you. It holds the radiation summary with dose and fields, the chemotherapy given, the pathology if surgery was done, and the calendar of checks.

Every one of these is available near you. Send the results. Your coordinator passes them to the team, and a new MRI is compared with the earlier ones here at no charge. A regrowth under watch and wait is treated with the operation that was postponed, and the results match immediate surgery.