Your first visit to the Radiation Oncology department will be for a detailed consultation with the Radiation Oncologist. Any recommendation for radiation therapy must be based on a detailed evaluation of the patient - the individual circumstances, the nature and extent of the disease, the general state of health, and the beliefs and values of the patient. Frequently this involves an assessment of other medical problems and risks, family dynamics, and choosing the best of several alternative approaches to the cancer problem within the bounds of what is practical and compassionate for the patient.

The purpose of this consultation, then, is for the Radiation Oncologist to assess the patient, the disease, and to develop an understanding of what can and should be done for the patient's best interests; and for the patient and the family to understand what is being offered and what alternatives might exist. Using a conventional history and physical examination, laboratory studies, and a great reliance on imaging to define exactly what is and what is not involved with the cancer, the Radiation Oncologist develops a comprehensive plan for the treatment. This plan should consider exactly what needs to be included in the treated volume - the detectable tumor and areas at risk for spread; what normal tissues and organs are in or near the volume to be treated, how much radiation they can tolerate and still recover, and how best to exclude or protect them; the total radiation dose that will be needed to create the desired effect - whether cure or palliation; how much of that dose should be given and how often, to balance the conflicting needs - to treat the tumor adequately, to spare the normal tissues and reduce the risk of problems during (side effects) and after (complications) the course of therapy, and to integrate the radiation process into other treatments the patient may be receiving.

All this must be balanced with the understanding that the gross cancer must be killed if either cure or palliation is to be achieved; and that the risk of the undesired effects is greatest when you treat large volumes rapidly to high doses. No radiation dose given can ever be undone. There are very limited measures available to reverse radiation damage once it has taken place. So... from the beginning, the Radiation Oncologist must understand all the relevant factors, must formulate a comprehensive treatment plan taking all these issues into account - and must disclose all these issues to the patient and allow the patient to make a decision about proceeding. This last point is paramount. Each patient is in control of his/her body; the best any physician can offer is well-developed recommendations - the final decision rests with the patient.

Your Treatment PLAN AND CT/SIMULATION

Once the consultation has been completed, the Radiation Oncologist has formulated the treatment plan, the patient agrees and the referring doctors are informed, it's time to move ahead with putting the plan into action. The plan and its execution remain throughout under the direction of the Radiation Oncologist - but at this point other professionals join in to ensure that the treatment is delivered accurately day-to-day.

                                                       The first step after the consultation is treatment planning. The purpose of any radiation therapy program is to deliver a lethal amount of radiation to the cancer - but from the beginning we must consider how this can be done safely. We must avoid delivering equally high doses to the normal tissues next to or intimately involved with the tumor. In external beam radiation therapy we are treating a deep-seated tumor from outside the body, and the radiation beams will pass through normal structures on the way. It is usual to treat the tumor from two or more entry points with radiation beams that meet and "crossfire" the target volume deep within the patient’s body; this limits the radiation dose to the organs and tissues to a safe level. Normal tissues like brain, spinal cord, liver, lung, or kidney can be particular problems because they are more sensitive to the radiation effect than common tumors nearby might be, and may not recover   from radiation damage.

Often the Radiation Oncologist will request specialized imaging studies - most often CT or MRI imaging of the area of the body to be treated with the patient in the same position as will be used for treatment - to allow computerized mapping of the dose to be delivered into the tumor volume and adjacent organs as seen on the scan. This ensures that the entire tumor will be treated to a uniform and sufficiently high dose in a way that spares as much as possible of the normal tissues and organs nearby. It is usual to plan for the total area being treated to be reduced periodically during the course of therapy, and to move the entry points of the radiation beams, so that by the end of the whole program the highest radiation dose has been delivered to the smallest volume with the greatest concentration of cancer cells. By using shrinking fields and changing the treatment plan to bring the treatment beams through different areas of normal tissue on their way to the target, more and more of the nearby normal tissues can be excluded from receiving radiation. The treatment as planned should be precise, repeatable, comprehensive, and effective.

After the planning is completed to the Radiation Oncologist's satisfaction, we proceed to the simulation. This is a "dry run" of the proposed treatment, guided by the Radiation Oncologist's understanding of the disease and planning already performed. Using a diagnostic x-ray/fluoroscopy unit that exactly parallels the functions of the external beam radiation treatment machine (CT/simulator), the planned treatment portals - the points of entry for the radiation beams - are drawn on the patient.  The  X-rays are taken to verify that the plan does in fact treat the necessary regions of the body, and that the portals can be set precisely and reliably day after day through the course of treatment. The patient 's skin will be tattooed and frequently marked to guide the treatment setup from day to day, and measurements will be taken of the patient's body to reconfirm the computer plan and to allow final computerized calculations of radiation dose.

At this time some custom treatment devices will be made for most patients. Some of these - face masks, foam plastic cushions - form to the shape of the patient's body to position him for each treatment to ensure that all treatments are accurately targeted at the same point. Others - lead alloy blocks - are shaped to exclude as much normal tissue in and near the portals as possible to ensure that radiation is delivered only to the tissue that must be treated. Through all this process the Radiation Oncologist is supported by the therapists who make the devices and will deliver the treatment as prescribed; and a staff of Radiation Physic and Dosimetrists who develop the details of the treatment plan, confirm the accuracy of dose delivery, and help to monitor the precision of the daily treatments. Once the treatment is planned, the simulation competed, the devices fabricated, and the calculations completed, the patient is ready to start treatment.

Repeating the imaging studies, a repeat simulation, and revision of the custom blocks and other devices is necessary with each change in the treatment portals, to ensure the absolute precision of dose delivery with each change. However - sometimes critical normal tissues are so closely intertwined with the tumor mass that they can’t be excluded from the treatment volume by replanning, shielding, or any of these other tricks without shielding tumor that needs to be treated. We speak of an "unfavorable therapeutic ratio" when this problem emerges - when it’s more likely that the next dose of radiation will cause complications than that it will control the cancer. In such cases, the prudent Radiation Oncologist discusses the issue with his patient and with the other phyicians involved in the patient's care - and most likely will stop treatment in the face of insurmountable risks.