Radiation Therapy for Recurrence of Vaginal CancerMedical editor Kolbein Sundfør MD
Oslo University Hospital
Patients with local or regional recurrence after radical surgery for vaginal cancer can in many cases be cured with radical radiation therapy. Radiation therapy is the first choice of treatment if it has not been given previously, but surgery should always be considered.
Small, solitary metastases can also be treated to cure the disease, but surgery with possibly subsequent radiation therapy must be considered first.
For brain metastases, stereotactic radiation therapy is possible for a maximum of 1 to 3 metastases which are not too large. For solitary brain metastases, surgery may be possible. Multiple or large brain metastases are treated with total brain irradiation.
Treatment must be individualized. Treatment aimed at local control may be appropriate even if the there is a risk there may be subclinical spreading to other regions. Margins and total dose must be considered in light of the risk and time perspective.
- Distinct recurrence, heterogenous group
- To cure the disease, or palliate by local control.
|Target volume definitions from ICRU
(International Commission on Radiation Units and Measurements)
|GTV (Gross tumor volume)
||Palpable or visible/identifiable area of malignant growth.
|CTV (Clinical target volume)
||Tissue volume containing GTV and/or subclinical microscopic malignancy.
|ITV (Internal Target Volume)
||Volume containing CTV and one inner margin taking into account inner movements and revisions of CTV.
|PTV (Planning Target Volume)
||Geometric volume containing ITV and one Setup margin taking into account assumed variations for patient movements, variations in patient arrangement, and field modeling.
Examinations should determine the total extent of the tumor. The same examination requirements apply for curative treatment as for primary radiation therapy. At Oslo University Hospital (the Norwegian Radium Hospital), we prefer the MRI to be performed here for treatment planning purposes.
Radical radiation therapy is normally given as 64-70 Gy to the macroscopic tumor. A boost to a higher total dose may be considered towards small areas.
The dosage for external radiation therapy is planned using CT. This therapy can be combined with brachytherapy as part of the tumor boost if adequate coverage of the entire tumor area can be achieved (endovaginal possibly interstitial brachytherapy for defined tumor). Brachytherapy is then usually given after external radiation is finished including the external boost.
- 1.8-2 Gy per fraction is given as 3-4 fields toward the tumor.
- The number of fractions depends on the total dosage.
- Cisplatin is sometimes given once per week during the entire treatment period (6 courses), but this is assessed individually.
Most side effects occurring during treatment are due to healthy organs included in the radiation field.
Radiation therapy to the vagina may cause:
- Diarrhea and abdominal pain.
- Nausea, which may be enhanced by chemotherapy.
- Irritation of the bladder mucosa. This may cause symptoms resembling a urinary tract infection such as frequent urination, burning, pain, and light bleeding.
- Change in bone marrow.
- Vaginal mucosa may be dry and sore, and stenoses may occur in the vagina.
- Skin reactions are rare with the appropriate multiple field technique. The exception is when a tumor is close to the skin with risk volume such as in vulvar cancer. If a skin reaction should occur, it is usually in the gluteal fold.
- The ovaries are sensitive to radiation and will stop functioning after a small radiation dose compared to what is necessary to cover the risk areas and control the tumor. When irradiating the pelvis, it is not possible to preserve hormone production and the patient will enter menopause. Hormone substitution is not possible for patients treated for vaginal cancer.
- Do not rub the skin area treated with radiation; instead, gently pat it dry.
- Avoid using creams or lotions in the irradiated area.
- Allow the skin to air-dry.