High-dose-rate interstitial computed tomography-based brachytherapy for the treatment of cervical cancer: early results.

PURPOSE: There is limited published data on high-dose-rate interstitial brachytherapy (HDRBT) for cervical cancer resulting in no consensus on a fractionation schedule. This study reports our experience of CT-based HDRBT for treating locally advanced cervical cancer. METHODS AND MATERIALS: Forty-seven patients diagnosed with Stage IIB-IVA cervical cancer not suitable for intracavitary brachytherapy were treated with HDRBT from March 2005 to November 2010. All patients received external beam radiation therapy with a median dose of 45Gy and all had one interstitial implantation followed by 3.75-5Gy×5 fractions in a twice daily (BID) schedule. Total doses for clinical target volume and organs at risk, including rectum, bladder, and sigmoid, were summated and normalized to a biologically equivalent dose of 2Gy per fraction. At 3 months posttherapy, early response was assessed with clinical examination and positron emission tomography (PET/CT) imaging. RESULTS: Median clinical target volume D(90) (dose delivered to 90% of the clinical target volume) was 76.3 (59.0-86.9) Gy and the 2cc dose to the bladder, rectum, and sigmoid colon organs were 70.2 (55.9-77.7), 65.8 (54.9-80.6), and 56.5 (45.0-71.2) Gy, respectively. Posttreatment, 12 patients had evidence of persistent disease on PET/CT. Eleven of the 35 patients who had complete response developed recurrences. Two patients developed late Radiation Therapy Oncology Group ≥3 rectal toxicities. Two-year actuarial local control, disease-free survival, overall survival, and Grade ≥3 toxicities were 61%, 43%, 59%, and 10%, respectively. CONCLUSION: Our approach of a single implantation procedure followed by five fractions of HDRBT was well tolerated with early results demonstrating a moderate response and local control rate with acceptable toxicities.

MammoSite accelerated partial breast irradiation: a single-institution outcomes analysis with 2 years of followup.

PURPOSE: To provide longitudinal follow-up and assess the intermediate outcomes in breast cancer patients treated with the MammoSite radiation therapy system. METHODS AND MATERIAL: Ninety-two patients with histologically proven stage 0-II breast cancer were treated with MammoSite accelerated partial breast irradiation after breast-conserving surgery. The catheter was placed at the time of surgery or postoperatively. Treatment prescription was 3.4Gy b.i.d. for a period of five days using high-dose-rate afterloading. Clinical and dosimetric parameters including dose to 90% of PTV, volume of PTV receiving 100% of dose, volume of PTV receiving 150% of dose, edited PTV, and dose homogeneity index were analyzed as variables correlating with late effects. RESULTS: All patients received the prescribed treatment. Seventy-seven percent of patients had intraoperative catheter placement, which was associated with a higher rate of persistent seroma (79%). The presence of seroma did not affect cosmesis. Ten patients developed telangiectasia at a median of 20.5 months. Skin dose and balloon-to-skin distance had a significant correlation with the development of telangiectasia that significantly affected cosmetic grading. The telangiectasia incidence for maximum skin dose of >100% and >125% of the prescription dose were 28% and 63%, compared with 0% (p=0.0001) and 4.2% (p=0.0001) for doses of < or =100% and < or =125%, respectively. Overall, most patients had excellent cosmetic results, and local control of disease was excellent. CONCLUSIONS: MammoSite radiation therapy system demonstrates excellent local control and cosmetic outcome with extended followup. The maximum skin dose should be kept below 100% to reduce late effects on skin and improve cosmetic outcome. The persistence of seroma is higher with intraoperative placement of the catheter, and therefore postoperative placement is preferred.

High-dose rate brachytherapy (HDRB) for primary or recurrent cancer in the vagina.

PURPOSE: The purpose of this study was to evaluate the efficacy of HDR brachytherapy for primary or recurrent vaginal cancer. METHODS: Between the years 2000 to 2006, 18 patients with primary or recurrent vaginal cancer were treated with brachytherapy (HDRB). Six patients had primary vaginal cancer (stage II to IVA) while 12 were treated for isolated vaginal recurrence (primary cervix = 4, vulva = 1 and endometrium = 7). Five patients had previous pelvic radiation therapy. All except one patient received external beam radiation therapy to a median dose of 45 Gy (range 31.2-55.8 Gy). The HDRB was intracavitary using a vaginal cylinder in 5 patients and interstitial using a modified Syed-Nesblett template in 13 patients. The dose of interstitial brachytherapy was 18.75 Gy in 5 fractions delivered twice daily. The median follow-up was 18 months (range 6-66 months). RESULTS: Complete response (CR) was achieved in all but one patient (94%). Of these 17 patients achieving a CR, 1 had local recurrence and 3 had systemic recurrence at a median time of 6 months (range 6-22 months). The 2-year actuarial local control and cause-specific survival for the entire group were 88% and 82.5%, respectively. In subset analysis, the crude local control was 100% for primary vaginal cancer, 100% for the group with recurrence without any prior radiation and 67% for group with recurrence and prior radiation therapy. Two patients had late grade 3 or higher morbidity (rectovaginal fistula in one patient and chronic vaginal ulcer resulting in bleeding in one patient). Both these patients had prior radiation therapy. CONCLUSION: Our small series suggests that HDRB is efficacious for primary or recurrent vaginal cancer. Patients treated with primary disease and those with recurrent disease without prior irradiation have the greatest benefit from HDRB in this setting. The salvage rate for patients with prior radiation therapy is lower with a higher risk of significant complications. Additional patients and follow-up are ongoing to determine the long-term efficacy of this approach.

Placement technique and the early complications of balloon breast brachytherapy: Magee-Womens Hospital experience.

BACKGROUNDS AND OBJECTIVES: Open (OT) and percutaneous closed (PCT) techniques have been described for placement of the MammoSite catheter to deliver accelerated partial breast brachytherapy. We report early complications of both techniques. METHODS: A total of 125 patients underwent catheter placement for MammoSite high-dose rate brachytherapy, with 108 patients successfully completing treatment. The OT was used in 85 patients and PCT in 40 patients. The mean distance between the balloon surface and breast skin was 1.44 cm and 1.31 cm, respectively. Average skin dose was 278 cGy in the OT group and 295 cGy in the PCT group (P > 0.05). Average gross specimen size was 43.16 cm3 in the OT group and 62.19 cm3 in the PCT group. Median follow-up was 11 months for the OT group and 5 months for the PCT group. RESULTS: In 17 cases, the catheter was subsequently removed without the patient completing treatment. Two of the patients in the OT group (3%) developed a delayed abscess. The overall incidence of persistent seroma (>6 months) was 20% with all occurring in the OT group, 30% of those patients. There were no acute skin toxicities higher than grade 2. The overall cosmesis is excellent or good in 95% of patients. CONCLUSION: Despite short follow-up and a small sample size in this study, it seems that the MammoSite brachytherapy was well tolerated by patients with early stage breast cancer when using either the OT or PCT.

Breast skin doses from brachytherapy using MammoSite HDR, intensity modulated radiation therapy, and tangential fields techniques.

Skin doses from brachytherapy using MammoSite HDR, Intensity Modulated Radiation Therapy (IMRT), and conventional tangential fields techniques were compared. For each treatment technique, skin doses were measured using paired thermoluminescent dosimeters placed on the patient's skin: (i) directly above the balloon catheter during MammoSite HDR brachytherapy treatments and (ii) 4 cm inside the treatment borders during the IMRT and conventional breast treatments. The mean dose measured was about 58% of the prescription dose for the patients treated using the MammoSite technique. On the other hand, for patients treated with IMRT and tangential fields, the mean dose was found to be about 69% and 71% of the corresponding prescription dose. This study suggests that in breast cancer radiation treatments the MammoSite HDR technique reduces skin doses compared to IMRT and tangential field techniques.

High-dose-rate interstitial brachytherapy for gynecologic malignancies.

PURPOSE: The study aimed to assess the outcome of locally advanced cervical and vaginal cancer treated with high-dose-rate interstitial brachytherapy (HDRB). METHODS AND MATERIALS: Between 1998 and 2004, 16 previously unirradiated patients with locally advanced cervical and vaginal cancer not suitable for intracavitary brachytherapy because of distorted anatomy or extensive vaginal disease were treated with HDRB in combination with external beam radiotherapy. All patients received whole pelvis external beam radiation therapy (EBRT) followed by interstitial implantation. The median whole pelvis external beam dose was 45 Gy (range, 39.6-50.4 Gy) with 11 patients receiving parametrial boost to a median dose of 9 Gy. Twelve (75%) of these patients received chemotherapy concurrent with external beam. All patients received a single HDRB procedure using a modified Syed-Neblett template. A CT scan was performed postimplant for needle placement verification and treatment planning purpose. Dose was prescribed to the tumor volume based on the radiographic and clinical examination. All patients received 18.75 Gy in five fractions delivered twice daily. The median followup was 25 months (6-69 months). RESULTS: Median cumulative biologic effective dose (EBRT+HDRB) to tumor volume was 78.9 Gy10 with the range of 72.5-85.2Gy10. Median cumulative biologic effective dose for the rectum and bladder were 99.4 Gy3 (range, 79.6-107.8 Gy3) and 96.4 Gy3 (range, 78.3-105.3 Gy3), respectively. Complete response was achieved in 13 (81%) patients with 3 patients having persistent disease. Five of these 13 patients developed recurrence at a median time of 14 months (distant in 4 and local and distant in 1). The 5-year actuarial local control and cause-specific survival were 75% and 64%, respectively. In subset analysis, 5-year actuarial local control was 63% for cervical cancer patients and 100% for vaginal cancer patients. No patient had acute Grade 3 or 4 morbidity. Grade 3 or 4 delayed morbidity resulting from treatment occurred in 1 patient with 5-year actuarial rate of 7%. Three patients had late Grade 2 rectal morbidity and 1 patient had Grade 2 small bowel morbidity. CONCLUSIONS: Our series suggests that single interstitial implantation procedure with five fractions of 3.75 Gy each to target volume is an effective and safe fractionation schedule. The integration of imaging modality helps in decreasing dose to the critical organs. Additional patients and followup are ongoing to determine the long-term efficacy of this approach.

Twice-daily high-dose-rate brachytherapy for medically inoperable uterine cancer.

PURPOSE: Medically inoperable patients with uterine cancer pose a therapeutic challenge. We developed a twice-daily schedule of high-dose-rate brachytherapy (HDRB) after a single insertion procedure that required a hospitalization of 3 days. METHODS AND MATERIALS: Favorable patients were offered brachytherapy alone, and all other patients received HDRB after pelvic external beam radiation therapy (EBRT). The prescribed dose was 7Gyx5 fractions and 4-5Gyx4-5 fractions for those treated after EBRT. HDRB was delivered with a b.i.d. schedule (4-6-h interval). RESULTS: Twenty-two patients (21 Stage I, 1 Stage IIB) were deemed medically inoperable. Sixteen patients received EBRT followed by HDRB, and six received HDRB alone. There were no procedural complications or significant acute toxicity. No thromboembolic events occurred within 30 days of the implant. CONCLUSIONS: This technique allows patients to be treated using a single procedure for insertion, with brief hospitalization for twice-daily HDRB.