Modern radiation techniques for treating gynaecological cancers

What are gynecological cancers?­

A. Cancers of the female reproductive organs are called gynecological cancers. Among these are cancer of the body of the uterus (endometrial cancer), opening of the uterus (cancer of cervix), ovary, vagina and vulva.

 Q. What is radiotherapy?

A. Radiotherapy is one of the three methods of treating cancer, the other two being surgery and chemotherapy. Also called radiation or radiation oncology, this modality of cancer treatment involves targeting cancer with x rays or gamma rays and rarely, with  charged particles such as electrons and protons.

Q. What are modern radiation techniques?

A. Modern radiotherapy techniques are treatment methods that consist of computerised  modeling  of patients’ anatomy, software programs that, under direction of a radiation oncologist,  target cancer and protect normal tissues. In addition, synonymous with these techniques is the use of sophisticated hardware, i.e. treatment machines called linear accelerators, which have devices that shape the radiation to match the shape of the tumour. Some advanced linear accelerators also have provision for X rays or CT scans before or during a patient’s treatment session, to ensure accurate focusing of the radiation beam.

Q. How do modern radiation techniques help in better treatment of cervical cancer?

A. Radiotherapy is the main treatment for cervical cancer, except in very early stages when surgery may be used alone or in combination with radiotherapy.  Various modern radiotherapy techniques ensure safe and effective treatment for this cancer. These are IMRT or RapidArc, to reduce the effects of radiotherapy on normal structures adjacent to the cancer, i.e. small and large bowel, urinary bladder and bone marrow. Another technique, IGRT, which may be used in addition to IMRT / RapidArc, is aimed at ensuring accurate treatment by accounting for, and correcting,  changes in the patients position in reference to the treatment machine, i.e. linear accelerator , as well as changes in the internal organs vis a vis one another. The latter happens because of routine body functions like presence of urine, gas and stool  in the bladder and bowel, respectively.

Q. What is brachytherapy and is there some advance in this method too?

A. Brachytherapy is internal radiotherapy, i.e. insertion of a radiation source into the affected organ, delivering treatment in proximity to the tumour. Traditionally planned using x-rays, image guided brachytherapy is an advance wherein the radiation is directed on the basis of CT or MR scan, ensuring a dramatic improvement in efficacy. This is because x ray based planning incorporate neither  information of patients' anatomy nor that of the volume and extent of the cancer in an individual patient.  I practise  MR based brachytherapy   for cervix and am very satisfied  both with the additional  information that is received by doing an MRI as well as the outcomes achieved.

Q. How are intracavitary and interstitial brachytherapy different from each other. Intracavitary radiotherapy , the more common form of brachytherapy in cervical cancer consists of insertion of hollow applicators into the uterus and cervix using the body's normal passage and then inserting a  radiation source into these hollow applicators. Interstitial radiotherapy is used when the disease extends  farther away from the reach of applicators placed in the uterus and vagina.

Q. What has been the impact of these modern radiotherapy techniques on cure rates in cervical cancer? Is this dependent on the treatment machine?

A. There has been a significant improvement in outcomes even in advanced stages of cervical cancer/ cancer cervix. While the equipment is important, the  knowledge & skill set of the treating radiation oncologist and  meticulous attention to detail  by the treating  team, in each patient, is essential to  ensure correct treatment and extract the best from the treatment machine.

Q. What is the role of modern radiotherapy in endometrial cancer (body of uterus)?

A. Primarily treated with surgery, radiotherapy is used as post operative treatment in nearly all stages. The treatment varies according to the stage of the disease; modern radiation techniques have an important role in preventing recurrence of cancer and reducing side- effects. The treatment may comprise of external beam radiotherapy i.e. IMRT / RapidArc with or without IGRT or may be in the form of brachytherapy for the vagina. In some situations, these may be combined.

Q. What about other gynecological cancers?

A. Cancers of the vagina require radiotherapy.   Cancer of the  vulva, i.e. the external reproductive organs may be treated either with surgery or with a combination of radiotherapy and chemotherapy. The primary cancer is treated, along with lymph glands that lie in the groin. Here too, IMRT helps treat the cancer while sparing  adjacent normal organs.

Radiotherapy is used in special situations in the treatment of cancer of ovary.