High Dose Rate Cobalt-60 After Loading Intracavitary Therapy of the Uterine Cervical Carcinoma in Srinagarind Hospital , Analysis of Residual Disease

Carcinoma of the uterine cervix has been recognized to be the major problem of malignant diseases in developing countries particularly in Thai women (Sriamporn et al., 2004). The large tumor volumes in addition to the advanced staging of cases resulted in radioresistant tumors, which were contributing factors limiting the effectiveness of radiation therapy. In addition, the time gap between teletherapy and brachytherapy in most patients was reported to be more than 2 weeks due to limitation of hospital facilities (Pesee et al., 1995). The combination of these circumstances was an important factor influencing the selection of high dose rate Cobalt 60 brachytherapy fractionation. Definitive radiotherapy alone is the standard treatment in uterine cervical cancer (Bermudez et al., 2010). There is no consensus on the best technique of brachytherapy (Visser et al., 2001; Symonds, 2003). Perez CA, et al report evidence of less than 10% pelvic failure for cervical cancer at stage IB and IIA with tumor sizes less than 2 cm in diameter and pelvic failure rates of 30-50% have been reported in extensive cervical cancer (Perez et al.,1998).


Introduction
Carcinoma of the uterine cervix has been recognized to be the major problem of malignant diseases in countries particularly in Thai women (Sriamporn et al., 2004).The large tumor volumes in addition to the advanced staging of cases resulted in radioresistant tumors, which were contributing factors limiting the effectiveness of radiation therapy.In addition, the time gap between teletherapy and brachytherapy in most patients was reported to be more than 2 weeks due to limitation of hospital facilities (Pesee et al., 1995).The combination of these circumstances was an important factor influencing the selection of high dose rate Cobalt -60 brachytherapy fractionation.Definitive radiotherapy alone is the standard treatment in uterine cervical cancer (Bermudez et al., 2010).There is no consensus on the best technique of brachytherapy (Visser et al., 2001;Symonds, 2003).Perez CA, et al report evidence of less than 10% pelvic failure for cervical cancer at stage IB and IIA with tumor sizes less than 2 cm in diameter and pelvic failure rates of 30-50% have been reported in extensive cervical cancer (Perez et al.,1998).This retrospective study was therefore conducted on admissions between April 1986 and December 1988, to determine the extent of residual tumor of uterine cervical carcinoma after treatment using combined teletherapy 50Gy/25 fractions together with high dose rate Cobalt-60 brachytherapy of 850 cGy/fraction to point A weekly for 2 fractions, now designated as current combined treatment (CCT).

Objectives
The purpose of this retrospective study was to evaluate the extent of residual disease in uterine cervical cancer patients treated by using CCT.

Materials and Methods
This study was performed in the Radiotherapy Division, Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand 40002.Inclusion criteria were: (1) uterine cervical cancer FIGO stages IB-IVB treated with radiotherapy alone between April 1986 and December 1988 (2) treatment using CCT (3) completion of the treatment regimen (4) minimum

Results
Patient characteristics are summarized in Table 1 and the details of residual diseases in Tables 2-3.There were 3.5% of locoregional residual diseases.The residual diseases in stage IIB, IIIB and IVA were 2.78%, 3.37% and 50% , however, no evidence of residual diseases was found in stage IB and IIA .

Discussion
The control of tumors in the pelvis is crucial to the survival of the patients in all stages.Regarding intensitymodulated radiation therapy (IMRT), there was 14% of pelvic failure (Hasselle et al., 2011), however, the local control and overall survival were generally inconclusive (Veldeman et al., 2008).Recently, the report of pelvic failure of 3D-conformal radiotherapy using accelerated hyperfractionation without intracavitary brachytherapy was 14.3% (Matsuura et al., 2007).The pelvic tumor control of stages III-IVA cervical cancer patients treated with concurrent chemoradiation versus radiotherapy alone was 62% versus 59% (Perez, 1997).In reference to the radiotherapy and hyperthermia modality, the complete response rate for advanced cervix cancer was 77% (Franckena et al., 2009).Additionally, treatment failure in stage IIIB cervical cancer from the study of Mabuchi et al was between 35-66.7%(Mabuchi et al., 2010).
CCT resulted in 96.5% of complete response and overall 3.5% incidence of residual diseases.The incidences of residual diseases according to stages IIB, IIIB and IVA were 2.78%, 3.37% and 50%.It was noted that there was no evidence of residual diseases in stage IB and IIA.Although CCT demonstrated a high complete response rate and low residual diseases but it also showed a higher incidence of radiation morbidities (Pesee et al., 2010).Both radiation morbidities and high complete response might be influenced by HDR fractionation brachytherapy.The 5 year survival rate of stage IIIB in CCT revealed approximately 54.8% (Pesee et al., 2010).
In conclusion, CCT resulted in an incidence of 3.5% residual diseases and 96.5% of complete response.The residual diseases of stage IIB, IIIB and IVA were 2.78%,    Obstetricians, 1995).This project was approved by the Human Ethics Committee of Khon Kaen University (HE470104).
The residual disease was defined as the presence of persistent tumors that were noted 4-6 weeks after completion of treatment.Responses to treatment were assessed at 4-6 weeks after completion of treatment.In order to define a complete positive response, there could not be any residual tumor plus a negative papanicolaou smear and/or a negative biopsy in some suspicious cases.All patients were treated with Cobalt-60 teletherapy units.The prescribed dose of teletherapy was 50Gy/25 fractions, five fractions per week to the whole pelvis through AP and PA 15x15 cm 2 or 16x16 cm 2 port.The ports were extended to 15x18 cm 2 for the stage IIIA patients.In addition, the parametrial boosts of 200 cGy for 3-5 days after the completion of brachytherapy were provided to stage IIIB patients with massive tumor at the parametrium.Brachytherapy was performed by using high dose rate Cobalt-60 brachytherapy (RALSTRON -20B) about 2-4 weeks after completion of teletherapy with doses of 850cGy/fraction to point A for 2 fractions, once weekly fractionation.The point A doses were approximately 75.50 Gy for early stages, and approximately 81.50-85.50Gy for advanced stages.DOI:http://dx.doi.org/10.7314/APJCP.2012.13.9.4835 High Dose Cobalt-60 After Loading Intracavitary Therapy for Uterine Cervical Carcinoma 3.37% and 50%.It was noted that there was no evidence of treatment failure in stage IB and IIA.These data allow for a proposal to improve outcome primarily through early detection.Routine checking by a cervical screening program should be encouraged in asymptomatic women in order to detect the early cases before tumor progression.