High-Dose-Rate Monotherapy for Localized Prostate Cancer: 10-Year Results.

PURPOSE: High-dose-rate (HDR) brachytherapy was originally used with external beam radiation therapy (EBRT) to increase the dose to the prostate without injuring the bladder or rectum. Numerous studies have reported HDR brachytherapy is safe and effective. We adapted it for use without EBRT for cases not requiring lymph node treatment. PATIENTS AND METHODS: We entered the patient demographics, disease characteristics, and treatment parameters into a prospective registry and serially added follow-up data for 448 men with low-risk (n=288) and intermediate-risk (n=160) prostate cancer treated from 1996 to 2009. Their median age was 64 years (range 42-90). The median prostate-specific antigen (PSA) level was 6.0 ng/mL (range 0.2-18.2). The Gleason score was ≤6 in 76% and 7 in 24%. The median dose was 43.5 Gy in 6 fractions. The clinical and biochemical disease control and survival rates were calculated. Adverse events were graded according to the Common Toxicity Criteria of Adverse Events. RESULTS: The median follow-up period was 6.5 years (range 0.3-15.3). The actuarial 6- and 10-year PSA progression-free survival was 98.6% (95% confidence interval [CI] 96.9%-99.4%) and 97.8% (95% CI 95.5%-98.9%). Overall survival at 10 years was 76.7% (95% CI 69.9%-82.2%). The local control, distant metastasis-free survival, and cause-specific survival were 99.7% (95% CI 97.9%-99.9%), 98.9% (95% CI 96.3%-99.7%), and 99.1% (95% CI 95.8%-99.8%). T stage, initial PSA level, Gleason score, National Comprehensive Cancer Network risk group, patient age, and androgen deprivation therapy did not significantly correlate with disease control or survival. No late grade 3 to 4 rectal toxicities developed. Late grade 3 to 4 genitourinary toxicity occurred in 4.9% (grade 3 in 4.7%). CONCLUSIONS: HDR monotherapy is a safe and highly effective treatment of low- and intermediate-risk prostate cancer.

Early clinical outcomes of ultrasound-guided CT-planned high-dose-rate interstitial brachytherapy for primary locally advanced cervical cancer.

PURPOSE: To report early clinical outcomes of high-dose-rate interstitial image-guided brachytherapy (BT) in the definitive management of locally advanced cervical cancer. METHODS: We retrospectively analyzed 31 locally advanced cervical cancer patients treated at our institution between January 2010 and April 2013. About 88% had advanced disease based on the International Federation of Gynecology and Obstetrics guidelines, and 87% received concurrent chemotherapy. All patients were treated with external beam radiation therapy to a median dose of 45 Gy (range, 39.6-58 Gy) before receiving BT. High-dose-rate BT was delivered in a single implant to a median dose of 6 Gy × five fractions to a CT-defined volume. Median total equivalent 2-Gy dose, dose covered by 90% of the high-risk clinical target volume (HR-CTV D90), and HR-CTV were 84, 87.4, and 49.9 cc, respectively. Kaplan-Meier method was used for actuarial survival analysis, and toxicity was graded using Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: Median followup was 19.3 months. Two-year actuarial local control, regional control, and distant metastasis (DM) were 90%, 93%, and 23.6%, respectively. Two-year disease-free survival was 55%. Genitourinary, gastrointestinal, or gynecologic Grade 3 toxicity was seen in 5 patients (3 T4a and 2 T3b) for crude rates of 13%, 7%, and 3%, respectively. Stratifying HR-CTV by <30 and >30 cc and then by HR-CTV D90 of <85, 85-90, and >90 Gy showed that 100% of the local failures, regional failures, DM, and G3 toxicity occurred in >30 cc group. The rate of DM was also significantly higher in the >30 cc group (p = 0.036). CONCLUSIONS: An interstitial approach can achieve excellent outcomes in cases where intracavitary and/or hybrid approaches are either not suitable or not available.

Electronic brachytherapy for postsurgical adjuvant vaginal cuff irradiation therapy in endometrial and cervical cancer: a retrospective study.

PURPOSE: A new platform for brachytherapy called electronic brachytherapy (EBT) has been developed, which uses a miniature X-ray source to generate low-energy radiation. A retrospective study of adverse events and clinical outcomes in patients treated with EBT to the vaginal cuff, either as monotherapy or in combination with external beam radiation therapy (EBRT), was conducted. METHODS AND MATERIALS: Medical records were reviewed from 16 patients treated with postoperative EBT for endometrial (n=13) or cervical cancer (n=3) between February 2009 and November 2010. Patients received either intracavitary vaginal EBT alone or EBT in combination with EBRT. The radiobiologic effectiveness of EBT was assumed to be one. RESULTS: Median follow-up was 20.5 months (range, 7-36 months). When EBT was used alone (n=5), the median dose per fraction, number of fractions, and total dose delivered were: 6Gy (range, 5.5-6.2Gy), 5 fractions (range, 5-6), and 30Gy (range, 30-34Gy), respectively. When EBT was combined with EBRT, the EBT component median dose per fraction, number of fractions, and total dose delivered were: 5Gy (range, 4.5-7Gy), 2 fractions (range, 2-4), and 14Gy (range, 9-20Gy), respectively. The median EBRT dose was 45Gy (range, 45-49.2Gy). Our local control rate, locoregional (pelvic) control rate, and overall survival rate were 94%, 94%, and 88%, respectively. Of the 16 patients, 4 patients reported Grade 2 or greater toxicity (25%); however, there were no Grade 4-5 adverse events. Gynecologic, genitourinary, and gastrointestinal adverse events accounted for 57% (n=4), 43% (n=3), and 0% (n=0) of all Grade 2 or greater side effects. No Grade 2 or higher toxicities were noted in patients treated with EBT alone. CONCLUSION: EBT is an acceptable means of delivering postoperative vaginal brachytherapy and appears comparable with other methods; as the sole method of treatment, the toxicity rates of EBT are low.