International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationsHigh dose rate transperineal interstitial brachytherapy for cervical cancer: high pelvic control and low complication rates☆
Introduction
The goals of radiation therapy of cervical cancer are eradication of local and regional tumor (in the cervix, parametria and within the pelvis) and avoidance of treatment related morbidity. Conditions that lead to a successful radiation therapy outcome are (i) disease limited to the pelvis, (ii) favorable radiation tumor biology, and (iii) optimal total radiation doses and the creation of a dose differential between normal tissue and tumor. Under certain circumstances, standard intracavitary tandem and ovoid applicators are incongruent with the distribution of the disease. Cases with extensive disease in the cervix, obliteration of the cervical os, narrow fornices, extensions of disease into the lower vagina or infiltrations laterally into the parametria beyond the high dose range of the intracavitary applicators are examples associated with a high incidence of local failure and more complications involving the small bowel, bladder, and rectum.
Two complementary technological advances in radiation therapy address the limitations of standard intracavitary applications; they are interstitial (IS) brachytherapy and high dose rate (HDR) remote afterloading. Interstitial implants provide anatomical access so that the radiation sources can be positioned strategically within and around the cancer. HDR creates optimal dose distributions by precisely controlling source location and dwell time duration. The combination of IS implantation and HDR brachytherapy permits the delivery of a high dosage to the tumor and relatively less dosage to adjacent normal tissues. When HDR brachytherapy is sufficiently fractionated and combined with external beam radiotherapy, there is potential for improved local tumor control and reduction of treatment morbidity.
We present a retrospective analysis of our experience using IS-HDR brachytherapy with previously untreated cervical cancers.
Section snippets
Methods and materials
All patients were examined and staged during the initial consultation and again prior to implantation while under anesthesia. Clinical FIGO staging was by consensus of the brachytherapist and gynecologic oncologist. Additional work-up consisted of cystoscopy, sigmoidoscopy, chest x-ray, abdominal, and pelvic computerized tomography (CT) or magnetic resonance imaging (MRI) scans, complete blood counts, liver and renal chemistries. Biopsy confirmation of invasive carcinoma was obtained in all
Survival
At the conclusion of the study 36 (58%) patients were alive and 34 (55%) were alive with no evidence of disease. The 5-year actuarial survival for all patients was 52% and DFS was 48%. Figure 2 displays the 5-year DFS; Stage I = 81%, Stage II = 47%, Stage III = 39%, and Stage IV = 0%. When the 10 patients who received chemotherapy were excluded from analysis there was no difference in the DFS.
Tumor control
Data on local control, regional control, and distant metastasis for all 62 patients are presented by
Discussion
Brachytherapy is an essential component in the treatment of cervical carcinoma. One of the advantages and the reason for its use is that high doses of radiation are delivered to the tumor in the immediate location of the sources. In addition, with a well-placed implant, the bladder and rectum receive significantly lower doses than the tumor. Fletcher’s three conditions for satisfactory brachytherapy insertions are: (i) The geometry of the radioactive sources must prevent underdosed regions on
Conclusions
We report results and complication rates for carcinoma of the cervix treated with external beam radiotherapy to the pelvis and HDR interstitial brachytherapy. The transperineal template IS implant catheters should fully encompass the tumor and entry into the bladder and rectum should be avoided. HDR technology provides the means to achieve optimal tumor doses and to maintain bladder and rectum doses equal or less than 70–80% of the target. The cases in this study were selected based on having
References (31)
- et al.
High-dose-rate versus low-dose-rate intracavitary brachytherapy for carcinoma of the cervix
Int J Radiat Oncol Biol Phys
(1990) - et al.
Analysis of pelvic control and impact on survival in carcinoma of the uterine cervix treated with radiation therapy alone
Int J Radiat Oncol Biol Phys
(1988) - et al.
The influence of tumor size and morphology on the outcome of patients with FIGO stage IB squamous cell carcinoma of the uterine cervix
Int J Radiat Oncol Biol Phys
(1994) - et al.
Pretreatment and treatment factors associated with improved outcome in squamous carcinoma of the uterine cervixA final report of the 1973 and 1978 patterns of care studies
Int J Radiat Onc Biol Phys
(1991) - et al.
Treatment of extensive carcinoma of the cervix with the “transperineal parametrial butterfly” a preliminary report on the revival of Waterman’s approach
Int J Radiat Oncol Biol Phys
(1978) - et al.
The Syed-Neblett interstitial template in locally advanced gynecological malignancies
Int J Radiat Oncol Biol Phys
(1983) - et al.
Interstitial therapy of perineal and gynecological malignancies
Int J Radiat Oncol Biol Phys
(1983) - et al.
Treatment of advanced cancer of the cervix with transperineal interstitial irradiation
Int J Radiat Oncol Biol Phys
(1983) - et al.
Parametrial interstitial brachytherapy for advanced or recurrent pelvic malignancyThe Harvard/Stanford experience
Gynecol Oncol
(1995) - et al.
Comparison of high and low dose rate remote afterloading for cervix cancer and the importance of fractionation
Int J Radiat Oncol Biol Phys
(1991)
Dose fractionation, dose rate and iso-effect relationships for normal tissue responses
Int J Radiat Oncol Biol Phys
HDR Remote afterloading gynaecological template interstitial brachytherapy: Rationale, indications and technique
Activity(Internaltional Nucletron Radiotherapy Journal)
Late effects of normal tissues consensus conference
Int J Radiat Oncol Biol Phys
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Work performed at California Endocurietherapy Cancer Center, Oakland, California.