**1. Introduction**

Endometrial cancer is the most common gynecologic cancer in developed countries with the cumulative risk rate of 1.71% [1]. The median age at the time of diagnosis is 63 years and about 90% of the patients are above 50 years of age. However, 4% of the patients are diagnosed under the age of 40 years [2]. The vast majority (80%) of endometrial cancer patients are diagnosed at early stages and while the 5-year survival rate is 95%, it significantly decreases in patients with local and distant metastases (68 and 17%, respectively) [3]. The standard treatment of endometrial cancer is total abdominal hysterectomy and bilateral salpingooophorectomy (TAH + BSO). Lymphadenectomy is performed in suitable patients when indicated [4, 5]. Adjuvant radiotherapy may be recommended for patients in advanced age who have high-grade disease, deep myometrial invasion, LVSI positivity, risk factors such as large tumor diameter, lymph node invasion and advanced stage disease (**Table 1**)[6–9].

*endometrial cancer; GOG, gynecologic oncology group.*


**Table 1.**

*High-intermediate risk groups in FIGO stage I endometrial cancer as defined by PORTEC-1 and GOG 99.*

The risk groups had previously been addressed in many studies (PORTEC-1, GOG 99 studies) and finally a consensus was reached by the European Society For Medical Oncology (ESMO), European Society for Radiotherapy and Oncology (ESTRO) and the European Society Of Gynecological Oncology (ESGO) in 2014 (**Table 2**)[9].

In the randomized controlled studies of GOG (Gynecological Oncology Group) 99 and PORTEC-1 (Operative Radiation Therapy in Endometrial Cancer), the patients who had intermediate risk factors were divided to two groups and while one group received external beam radiotherapy (EBRT), the other group was followed-up without treatment. The groups in both studies have been presented in **Table 1** [6, 8].

No effect could be demonstrated on the overall survival in either of the two studies. However, the recurrence rate decreased to 3–6% from 12 to 15% in patients with intermediate risk factors who received EBRT. In the subgroup analyses, while the recurrence rate decreased to 5–6% from 18 to 26% in patients in the high-intermediate (H-I) risk group, it decreased to 2% from 5 to 6% in the low-intermediate risk group. Side effects of radiation therapy were seen at a high rate in both studies despite an excellent local control. While the toxic effect rate was 26% in the EBRT group in PORTEC 1, it was 4% in the untreated group (p < 0.0001) [10]. Hematological, genitor-urinary, gastro-intestinal and skin complications were also significantly higher in the GOG 99 study group compared


**157**

**Figure 2.**

*Cylinder vaginal applicators (Delclos dome cylinder).*

**Figure 1.**

*Vaginal ring applicator.*

*Brachytherapy in Endometrial Cancer*

**2. Vaginal brachytherapy**

*2.1.1 Vaginal applicators*

**2.1 Vaginal brachytherapy (VB) application**

*DOI: http://dx.doi.org/10.5772/intechopen.92703*

to the untreated group [6]. In the long-term quality of life data of the PORTEC-1 study, urinary and intestinal functions were found to be poorer compared to the untreated group [11]. Local radiation therapies have come to the foreground due to the high incidence of the toxic effects of pelvic EBRT and their significance has gradually increased. Brachytherapy is applied in two ways, namely intra-cavitary or interstitial radiation therapy. Intra-cavitary brachytherapy is the presence of a therapeutic radioactive isotope within the body space, for example, vaginal and intra-uterine brachytherapy. Radioactive isotopes are directly inserted within the tissue in interstitial brachytherapy as in the treatment of cervical or endometrial cancers that have reached the lateral walls. The intra-cavitary brachytherapy technique is the most commonly used technique in gynecologic oncology.

Various vaginal applicators are available in gynecologic oncology depending on the location of the radiation source and whether it contains a cover or not. The Fletcher-Suit-Delclos system is among the most commonly used (**Figure 1**). Vaginal ring applicators are mostly used in HDR. Cylinder vaginal applicators, i.e., Delclos

dome cylinder are used in patients undergoing hysterectomy (**Figure 2**).

#### **Table 2.**

*New risk groups to guide adjuvant therapy use.*

*Brachytherapy in Endometrial Cancer DOI: http://dx.doi.org/10.5772/intechopen.92703*

*Translational Research in Cancer*

*endometrial cancer; GOG, gynecologic oncology group.*

(**Table 2**)[9].

**Table 1.**

**Risk group Description**

Metastatic Stage IVB

*New risk groups to guide adjuvant therapy use.*

invasion

Stage II

carcinosarcoma) Advanced Stage III residual disease and stage IVA

The risk groups had previously been addressed in many studies (PORTEC-1, GOG 99 studies) and finally a consensus was reached by the European Society For Medical Oncology (ESMO), European Society for Radiotherapy and Oncology (ESTRO) and the European Society Of Gynecological Oncology (ESGO) in 2014

High-intermediate risk group At least 2/3 of above any age, all three of above risk factors

*FIGO, International Federation of Gynecology and Obstetrics; PORTEC, postoperative radiation therapy in* 

*High-intermediate risk groups in FIGO stage I endometrial cancer as defined by PORTEC-1 and GOG 99.*

Age >60 See below Grad· 3 2–3 Myometrial invasion >50% (outer 1/2) >66.6%·(outer 1/3) Lvmphvasctilar space invasion N/A Present

**PORTEC-1 GOG 99**

age > 50, two of above risk factors age > 70, one of above risk factors

In the randomized controlled studies of GOG (Gynecological Oncology Group)

99 and PORTEC-1 (Operative Radiation Therapy in Endometrial Cancer), the patients who had intermediate risk factors were divided to two groups and while one group received external beam radiotherapy (EBRT), the other group was followed-up without treatment. The groups in both studies have been presented in **Table 1** [6, 8]. No effect could be demonstrated on the overall survival in either of the two studies. However, the recurrence rate decreased to 3–6% from 12 to 15% in patients with intermediate risk factors who received EBRT. In the subgroup analyses, while the recurrence rate decreased to 5–6% from 18 to 26% in patients in the high-intermediate (H-I) risk group, it decreased to 2% from 5 to 6% in the low-intermediate risk group. Side effects of radiation therapy were seen at a high rate in both studies despite an excellent local control. While the toxic effect rate was 26% in the EBRT group in PORTEC 1, it was 4% in the untreated group (p < 0.0001) [10]. Hematological, genitor-urinary, gastro-intestinal and skin complications were also significantly higher in the GOG 99 study group compared

Low Stage I endometrioid, erade 1–2, <50% myometrial invasion, LVSI negative Intermediate Stage I endometrioid, grade 1–2, ≥50% myometrial invasion, LVSI negative High-intermediate Stage I endometrioid, grade 3, <50% myometrial invasion, regardless of LVSI status

Stage III endometrioid. no residual disease

High Stage I endometrioid, grade 3, ≥50% myometrial invasion, regardless of LVSI status

Stage I endometrioid. 1–2, LVSI unequivocally positive, regardless of depth of

Non-endometrioid (serous or clear cell or undifferentiated carcinoma, or

**156**

**Table 2.**

to the untreated group [6]. In the long-term quality of life data of the PORTEC-1 study, urinary and intestinal functions were found to be poorer compared to the untreated group [11]. Local radiation therapies have come to the foreground due to the high incidence of the toxic effects of pelvic EBRT and their significance has gradually increased. Brachytherapy is applied in two ways, namely intra-cavitary or interstitial radiation therapy. Intra-cavitary brachytherapy is the presence of a therapeutic radioactive isotope within the body space, for example, vaginal and intra-uterine brachytherapy. Radioactive isotopes are directly inserted within the tissue in interstitial brachytherapy as in the treatment of cervical or endometrial cancers that have reached the lateral walls. The intra-cavitary brachytherapy technique is the most commonly used technique in gynecologic oncology.
