HDR and MDR intracavitary treatment for carcinoma of the uterine cervix. A prospective randomized study

High dose rate versus low dose rate intracavity brachytherapy for locally advanced uterine cervix cancer

BACKGROUND

This is an updated version of the original Cochrane review published in 2010 (Issue 7).Carcinoma of the uterine cervix is the second most common cancer and the third leading cause of cancer death among women. Radiotherapy has been used successfully to treat cervical cancer for nearly a century. The combination of external beam radiotherapy (EBRT) and intracavity brachytherapy (ICBT) has become a standard treatment for cervical cancer. Whether high dose rate (HDR) or low dose rate (LDR) brachytherapy improves outcomes in terms of local control rates, survival and complications for women with cervical cancer remains controversial.

OBJECTIVES

To assess the efficacy and safety of HDR versus LDR ICBT in combination with EBRT for women with uterine cervical cancer.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (1966 to March 2014), EMBASE (1974 to March 2014), and the Chinese Biomedical Literature Database (CBM) (1978 to March 2014) for relevant original, published trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared HDR with LDR ICBT, combined with EBRT, for women with locally advanced uterine cervical cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data using standardised forms. Primary outcome measures included overall survival (OS), relapse-free survival (RFS) and pelvic control rate, while secondary outcomes included rates of recurrence and complications.

MAIN RESULTS

Four studies involving 1265 women met the inclusion criteria. In our meta-analysis to compare HDR and LDR ICBT, the pooled risk ratios (RRs) were 0.95 (95% confidence interval (CI) 0.79 to 1.15), 0.93 (95% CI 0.84 to 1.04) and 0.79 (95% CI 0.52 to 1.20) for 3-, 5- and 10-year overall survival rates respectively; and 0.95 (95% CI 0.84 to 1.07) and 1.02 (0.88 to 1.19) for 5- and 10-year disease-specific survival (DSS) rates respectively. The RR for RFS was 1.04 (95% CI 0.71 to 1.52) and 0.96 (95% CI 0.81 to 1.14) at 3- and 5- years. For local control rates the RR was 0.95 (95% CI 0.86 to 1.05) and 0.95 (95% CI 0.87 to 1.05) at 3- and 5- years; with a RR of 1.09 (95% CI 0.83 to 1.43) for locoregional recurrence, 0.79 (95% CI 0.40 to 1.53) for local and distant recurrence, 2.23 (95% CI 0.78 to 6.34) for para-aortic lymph node metastasis, and 0.99 (95% CI 0.72 to 1.35) for distance metastasis. For bladder, rectosigmoid and small bowel complications, the RR was 1.33 (95% CI 0.53 to 3.34), 1.00 (95% CI 0.52 to 1.91) and 3.37 (95% CI 1.06 to 10.72) respectively. These results indicated that there were no significant differences except for increased small bowel complications with HDRs (P = 0.04).

AUTHORS' CONCLUSIONS

Since the last version of this review, no new studies were identified for inclusion in this review to provide additional information. This review showed no significant differences between HDR and LDR ICBT when considering OS, DSS, RFS, local control rate, recurrence, metastasis and treatment related complications for women with cervical carcinoma. Due to some potential advantages of HDR ICBT (rigid immobilization, outpatient treatment, patient convenience, accuracy of source and applicator positioning, individualized treatment) we recommend the use of HDR ICBT for all clinical stages of cervix cancer. The overall risk of bias was high for the included studies as many of the items were either of high or unclear risk. The GRADE assessment of the quality of the evidence was low to moderate.

High dose rate versus low dose rate intracavity brachytherapy for locally advanced uterine cervix cancer

BACKGROUND

Carcinoma of the uterine cervix is the second most common cancer and the third leading cause of cancer death among women. Radiotherapy has been used successfully to treat cervical cancer for nearly a century. The combination of external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT) has become a standard treatment modality for cervical cancer. Depending on the difference in dose rate on 'Point A' (located 2 cm above the cervical os and 2 cm lateral to the central axis of the uterus), the ICBT is divided into three modalities: low dose rate (LDR), high dose rate (HDR) and medium dose rate (MDR). Despite the practical advantages of HDR, it is necessary to investigate further the efficacy and safety of HDR brachytherapy compared to LDR brachytherapy. Questions arise as to whether HDR or LDR brachytherapy improves results for patients with cervical cancer in terms of local control rates, survival and complications related to treatment.

OBJECTIVES

To assess the efficacy and safety of HDR- versus LDR-ICBT for patients with uterine cervical cancer.

SEARCH STRATEGY

We searched the Cochrane Gynaecological Cancer Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 4), MEDLINE (1966 to November 2009), EMBASE (1974 to November 2009), Chinese Biomedical Literature Database (CBM) (1978 to November 2009) for relevant original, published trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared HDR- with LDR-ICBT, combined with EBRT, for patients with locally advanced uterine cervical cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data using standardised forms. Primary outcome measures included overall survival (OS), relapse-free survival (RFS) and pelvic control rate, while secondary outcomes included rates of recurrence and complications.

MAIN RESULTS

Four studies involving 1265 patients met the inclusion criteria. In our meta-analysis to compare HDR and LDR, the pooled RRs were 0.95 (95% CI 0.79 to 1.15), 0.93 (95% CI 0.84 to 1.04) and 0.79 (95% CI 0.52 to 1.20) for 3-, 5- and 10-year overall survival rates; and 0.95 (95% CI 0.84 to 1.07) and 1.02 (0.88 to 1.19) for 5- and 10-year disease-specific survival (DSS) rates. The RR for RFS was 1.04 (95% CI 0.71 to 1.52) and 0.96 (95% CI 0.81 to 1.14) at three and five years. For local control rates the RR was 0.95 (95% CI 0.86 to 1.05) and 0.95 (95% CI 0.87 to 1.05) at three and five years; with a RR of 1.09 (95% CI 0.83 to 1.43) for locoregional recurrence, 0.79 (95% CI 0.40 to 1.53) for local and distance recurrence, 2.23 (95% CI 0.78 to 6.34) for para-aortic lymph node metastasis and 0.99 (95% CI 0.72 to 1.35) for distance metastasis. For bladder, rectosigmoid and small bowel complications, the RR was 1.33 (95% CI 0.53 to 3.34), 1.00 (95% CI 0.52 to 1.91) and 3.37 (95% CI 1.06 to 10.72), respectively. These results indicate that there were no significant differences except for increased small bowel complications with HDR (P = 0.04).

AUTHORS' CONCLUSIONS

This review showed no significant differences between HDR- and LDR-ICBT when considering OS, DSS, RFS, local control rate, recurrence, metastasis and treatment related complications for women with cervical carcinoma. Due to some potential advantages of HDR-ICBT (rigid immobilization, outpatient treatment, patient convenience, accuracy of source and applicator positioning, individualized treatment) we recommend the use of HDR-ICBT for all clinical stages of cervix cancer.

Effect of high-dose-rate 192Ir source activity on late rectal bleeding after intracavitary radiation therapy for uterine cervix cancer

PURPOSE

This retrospective study analyzed the effect of the activity of high-dose-rate (HDR) (192)Ir source on late rectal bleeding after HDR intracavitary radiotherapy (ICRT) in patients with uterine cervix cancer.

METHODS AND MATERIALS

One hundred thirty-two patients who underwent HDR-ICRT and external beam radiotherapy (EBRT) were analyzed. The rectal point dose in ICRT was calculated by inserting a lead wire into the rectal lumen and summed with the whole-pelvic EBRT dose. The rectal biologic effective dose (BED) was calculated. The relationship between averaged source activity or the BED and late rectal bleeding were analyzed.

RESULTS

Three-year actuarial rectal bleeding probabilities were 46% (> or =100 Gy(3)) and 18% (< or = 100 Gy(3)), respectively (p < 0.005). When patients were divided into four groups according to rectal BED (> or = or < or =100 Gy(3)) and source activity (> or = or < or =2.4 cGy.m(2).h(-1)), the group with both a high BED and high activity showed significantly greater probability (58% at 3 years; p < 0.005). It was noted that the probability of the group with BED of 100 Gy(3) or greater was high, but that was not the case with 2.4 cGy.m(2).h(-1) or less.

CONCLUSION

This is the first clinical report concerning the source activity effect of HDR (192)Ir on late rectal bleeding in patients undergoing HDR-ICRT. This suggests that when source activity is higher than 2.4 cGy.m(2).h(-1), ICRT should be performed with more caution not to exceed 100 Gy(3) in total.

Brachytherapy for early oral tongue cancer: low dose rate to high dose rate

To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n = 341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer.