Brachytherapy

A comparison of brachytherapy techniques for partial breast irradiation

Jaroslaw T. Hepel, David E. Wazer — 2011-08-05

Abstract: Accelerated partial breast irradiation has emerged as an important treatment option for select patients with early-stage breast cancer. Numerous techniques for the delivery of accelerated partial breast irradiation have been developed involving both external beam and brachytherapy techniques. Brachytherapy techniques in general have the advantage of directly targeting the tumor bed and are not hampered by the requirement for large planning target volume margins needed with external beam techniques to account for uncertainties in targeting a very mobile organ, easily affected by patient and respiratory motion. We review established brachytherapy techniques and new emerging approaches. Technical considerations, available clinical data, advantages and shortcomings of each technique are reviewed.

Three-dimensional image-based high-dose-rate interstitial brachytherapy for vaginal cancer

2011-06-13

Abstract: Purpose: To evaluate dosimetric and clinical outcomes of three-dimensional (3D) image–based high-dose-rate (HDR) interstitial brachytherapy (HDRB) in patients with vaginal cancers.Methods and Materials: Thirty patients with vaginal cancers were treated with HDRB using Syed-Neblett template. CT scan was done after placement of needles for confirmation of placement and treatment planning. The target volume and organs at risk, including clinical target volume (CTV), rectum, bladder, and sigmoid colon, were contoured on CT scans. Twenty-eight (93.3%) patients received external beam radiation therapy at a median 45 (24.0–50.4)Gy in 12–28 fractions, followed by HDRB at 3.75–5.0Gy per fraction in five fractions. Total doses for CTV and organs at risk from external beam radiation therapy and HDRB were summated and normalized to a biologically equivalent dose of 2Gy per fraction.Results: Seventeen patients (56.7%) with primary vaginal cancer and 13 patients (43.3%) with recurrent vaginal cancers were treated with 3D HDRB. The mean CTV was 39.3±25.7 cm3, and the median tumor diameter was 3.3 (1.3–8.0)cm. The median biologically equivalent dose of 2Gy per fraction for 2cc of bladder, rectum, and sigmoid was 55.0, 56.3, 50.0Gy, respectively. The median D90 for high-risk CTV was 74.3 (36.3–81.1)Gy. The mean volume receiving 100%, 150%, and 200% of prescribed dose was 90.7±10.0%, 41.3±14.6%, and 17.7±8.3%, respectively. With a median followup of 16.7 months, the respective 1-/2-year locoregional and overall survival rates were 84.4%/78.8% and 82.1%/70.2%, respectively. There were no Grade ≥3 gastrointestinal complications. Late complications of Grade 3 vaginal ulceration and Grade 4 vaginal necrosis were seen in two cases.Conclusions: Initial results of 3D HDRB using our fractionation schedule in the treatment of vaginal cancers showed good local response with acceptable morbidities.

Inverse-planned gynecologic high-dose-rate interstitial brachytherapy: Clinical outcomes and dose–volume histogram analysis

2011-08-22

Abstract: Purpose: To present clinical outcomes and dose–volume histogram parameters of three-dimensional image–based high-dose-rate interstitial brachytherapy (HDR-ISBT) in patients with primary or recurrent gynecologic cancer unsuitable for intracavitary brachytherapy (ICB).Methods and Materials: Records of 43 women treated between 2001 and 2009 with iridium-192 gynecologic HDR-ISBT boost, using a Syed–Neblett template and inverse planning simulated annealing dose optimization, were reviewed. Median HDR-ISBT dose was 30Gy, delivered in 4–6Gy/fraction. Dose–volume histogram parameters recommended by the Groupe Européen de Curiethérapie–European Society for Therapeutic Radiology and Oncology for image-based ICB were analyzed. Total doses were normalized to 2Gy fractions (biologically equivalent dose in 2Gy fractions). Local control (LC) and survival were calculated using Kaplan–Meier method. Toxicities were defined according to Common Terminology Criteria for Adverse Events v3.0.Results: There were 34 primary malignancies (cervix=12, vagina=15, Bartholin’s gland=5, and vulva=2) and 9 recurrences. International Federation of Gynecology and Obstetrics stage distribution for primary cancers was I=2, II=13, III=15, and IV=4. Median followup was 19.3 months (range, 0–92.2). Two-year LC was 87% for primary cancers, and 45% for recurrent cancers, respectively (p=0.0175). Median V100, D90, and D100 for clinical target volume were 97.6%, 90.2, and 68.7Gy10, respectively. Median bladder and rectal D2cc were 76.6 and 79.5Gy3, respectively. Median urethral D10 was 80.6Gy3. Twelve patients experienced Grades 3 and 4 late morbidity, but toxicities were transient. Only 2 patients had persistent severe toxicities. A trend toward increased risk for vaginal necrosis was observed with a clinical target volume >84cc.Conclusions: HDR-ISBT may achieve good LC in gynecologic cancer unsuitable for ICB, especially in primary malignancies with a 2-year LC rate higher than 85%. Delivery of such high doses has potential advantages but may predispose to adverse effects, reversible in most cases.

Deaths within 12 months after 125I implantation for brachytherapy of prostate cancer: An investigation of radiation safety issues in Japan (2003–2010)

2011-09-19

Abstract: Purpose: The International Commission on Radiological Protection recommends removing the prostate before cremation if death occurs within 12 months after 125I brachytherapy. However, the incidence of death within this time frame has not been robustly investigated in any country. The purpose this study was to investigate the incidence and cause of death and actions taken when death has occurred within 12 months after 125I brachytherapy for prostate cancer in Japan.Methods and Materials: Data were extracted from the Japan Radioisotope Association database to investigate the total number of implantation cases, number of early deaths after implantation, cause of death, and postmortem actions between September 2003 and the end of June 2010 in Japan. Early death was defined as occurring within 12 months after 125I brachytherapy for prostate cancer.Results: During the study period, 15,427 patients underwent 125I brachytherapy and 43 (0.28%) died within 12 months after implantation. For 37 of the 43 patients (86%), the brachytherapy source was retrieved together with the prostate gland at autopsy; however, autopsy could not be performed in six (14%) of the deceased patients. The largest proportion of early deaths was because of cerebrovascular or cardiovascular disease (17/43, 40%), followed by malignant tumor (15/43, 35%), and respiratory disease or infection (7/43, 16%).Conclusions: The incidence of early deaths within 12 months after 125I brachytherapy in Japan was 0.28%. In almost all cases, the brachytherapy sources were removed in the intact prostate before the body was cremated and stored appropriately.

Globalization, implantation, cremation…Oh, my!

Lawrence T. Dauer — 2011-09-19

When speaking about the flattening of the world, former Secretary-General of the United Nations and Nobel Peace Prize winner, Kofi Annan, once stated, “It has been said that arguing against globalization is like arguing against the laws of gravity.” Medicine is certainly not immune to the globalization pull. Indeed, we have entered a new age of globalized medicine and even “medical tourism” never before even dreamed possible. In addition to opportunities offered by a worldwide information system, there are increasing demands on medicine to continue to fuel growth in both diagnosis and treatment. Indeed, the social media outlets have provided a new avenue for potential patients to learn about and seek forms of treatment, likely increasing overall demand. One obvious example is the crusade to end prostate cancer, the second most frequently diagnosed cancer, and the sixth leading cause of male cancer in the world with nearly a million cases diagnosed each year. In response, the use of permanent radioactive implants (brachytherapy) to treat selected localized prostate cancers continues to increase rapidly worldwide, especially because of the low degree of toxicity, improved quality of life, and a general, long-term, positive prognosis. In the United States, where approximately 220,000 new cases of prostate cancer are diagnosed each year, more than 40,000 implantations for localized prostate neoplasms are performed annually. In Europe, as in other locations, several thousand cases are already treated annually and this number continues to increase.

Rectal toxicity and rectal dosimetry in low-dose-rate 125I permanent prostate implants: A long-term study in 1006 patients

2011-07-15

Abstract: Objective: To describe the acute and late rectal toxicity in 1006 prostate brachytherapy patients implanted 1998–2003. To determine whether rectal dose–volume histogram as well as patient and treatment factors were associated with rectal toxicity.Methods and materials: Median followup was 60.7 months. Rectal dosimetry was calculated as dose–volume histogram of the rectum using Day 28 CT-based dosimetry and expressed as volume of the rectum in cc receiving 50%, 100%, and 150% of the prescription dose (VR50cc, VR100cc, and VR150cc, respectively). Univariate and multivariate analyses were performed to examine the influence of patient, implant, dosimetry, and learning curve factors on the development of acute and late toxicities using a modified Radiation Therapy Oncology Group (RTOG) scale. Acute toxicity was analyzed using logistic regression and late toxicity using Cox proportional hazards regression. Analysis of variance was used to examine the association between rectal toxicity and rectal dose.Results: Rectal dosimetry in 93.5% and rectal toxicity in 96.2% have been recorded. Median VR100=1.05cc. Late RTOG Grades 0, 1, 2, 3, and 4 were recorded in 68%, 23%, 7.3%, 0.9%, and 0.2% patients, respectively. On multivariate analysis, acute RTOG ≥2 rectal toxicity was associated with urinary retention (p=0.036) and learning curve (p=0.015); late RTOG ≥2 was associated with the presence of acute toxicity (p=0.0074), higher VR100 (p=0.030) and learning curve (p=0.027).Conclusions: Late rectal RTOG ≥2 rectal toxicity in this cohort was 8%. Increased VR100, presence of acute rectal toxicity, and learning curve were associated with higher rate of late RTOG ≥2 toxicity. Severe late rectal toxicity after prostate brachytherapy was rare.

Biochemical and clinical experience with real-time intraoperatively planned permanent prostate brachytherapy

2011-07-04

Abstract: Purpose: To evaluate patient characteristics and dosimetric parameters that predict biochemical failure (BCF) after real-time planned low-dose-rate prostate brachytherapy.Methods: From 1998 to 2008, a low-risk cohort by National Comprehensive Cancer Network criteria of 341 men with a median followup of 41.6 months was analyzed. This cohort had a median age of 65.1 years, prostate volume of 35.8cc, and pretreatment prostate-specific antigen of 5.6ng/mL. Patients had predominately Gleason 6 (95.9%) and T1c (81.3%) disease. About 3.6% of the patients received androgen deprivation therapy. Kaplan–Meier and Cox proportional hazards survival analysis methods were used to analyze predictors of BCF (Phoenix definition).Results: At 72 months, freedom from BCF was 91.1% (95% confidence interval=85.0–94.8). The median D90 was 145.9Gy, and the median V100 was 90.3%. Because of infrequent BCF, the following prostate volume groups were examined: 15–<25, 25–<35, 35–<45, and 45+cc. Of all possible predictors, only small prostate volume (15–<25cc group) was significantly associated with BCF (hazard ratio=8.44, 95% confidence interval=1.82–39.14, p=0.007). Using Kaplan–Meier analysis, time to BCF was also significantly increased in the lowest prostate volume 15–<25cc group with 24.1% failing at 48 months compared with 1.6–5.1% among the other groups.Conclusions: Real-time planned low-dose-rate prostate brachytherapy provides excellent biochemical control as a single-agent treatment for low-risk prostate cancer with 91.1% freedom from BCF at 72 months. Only prostate volume less than 25cc was an independent predictor of BCF.

Relationship between prostate-specific antigen bounce body fat distribution and body mass index in permanent seed brachytherapy for prostate cancer

2011-06-23

Abstract: Purpose: To analyze the influence of body mass index (BMI) and adipose tissue distribution on prostate-specific antigen (PSA) bounce after iodine-125 prostate brachytherapy.Methods and Materials: We studied 20 patients who had PSA bounce (≥0.50ng/mL) after exclusive prostate brachytherapy. These patients were compared with 48 patients without a bounce (<0.50ng/mL). All patients in the comparison group had a followup of ≥24 months and a last PSA ≤0.5ng/mL. Within these 48 patients, there was a group matched for age (n=20). Univariate and multivariate logistic models were estimated to assess the association between age, baseline PSA, prostate volume, D90, visceral fat (VF) volume, and BMI on PSA-bouncing status.Results: When comparing the patients with a bounce to those without, only BMI showed a significantly different distribution (mean, 25.18 vs. 27.47kg/m2; p=0.0342). On a multivariate analysis, BMI had an odds ratio of 0.85 (95% confidence interval, 0.71–0.99, p=0.049), indicating that an increase of 1kg/m2 in BMI is associated with a 15% reduction in the odds of having a bounce. In the univariate analysis with the matching patients, BMI was a significant predictor of a bounce (p=0.0147). In the multivariate conditional logistic model, BMI showed a trend toward an influence on a bounce (p=0.0615). All other factors, including VF, did not have any influence on a PSA bounce.Conclusions: Patients with a lower BMI are more likely to experience a PSA bounce ≥0.50ng/mL. VF did not have an influence on a PSA bounce.

Higher percentage of positive biopsy cores and Gleason score are associated with a greater degree of prostate gland shrinkage after neoadjuvant cytoreductive therapy

2011-08-08

Abstract: Purpose: To determine whether adverse pathologic features, including tumor grade and percent positive biopsy (PPB) cores, predict for prostate size reduction after neoadjuvant cytoreductive therapy.Methods and Materials: Eighty-two consecutive patients who were diagnosed with prostate cancer by transperineal template–guided mapping biopsy (TTMB) received neoadjuvant cytoreductive therapy. The median number of biopsy cores was 59. Thirty patients received a leutinizing hormone–releasing hormone agonist and bicalutamide, whereas 52 patients received bicalutamide (50mg daily) and dutasteride (0.5mg daily). A transrectal ultrasound volumetric study of the prostate gland and ellipsoid volume determinations of the prostate gland and transition zone (TZ) were obtained immediately before TTMB and at 90 days (±7 days) after the initiation of neoadjuvant medical therapy. Univariate and multivariate regression analyses were performed to identify predictors of prostate gland and TZ volume reduction.Results: At TTMB, the mean prostate volumetric and ellipsoid volumes were 55.4 cm3 and 49.0 cm3, respectively. After neoadjuvant medical therapy, the mean volumetric and ellipsoid prostate volumes were 30.8 cm3 and 28.5 cm3, respectively. On average, the prostate volume decreased by 43.9% and 41.0% on volumetric and ellipsoid measurements, respectively. The TZ volume decreased from 19.8 cm3 to 10.1 cm3 (mean volume reduction of 47.7%). In multivariate analysis, prostate volume cytoreduction was most closely associated with PPB (p=0.014), TTMB prostate volume (p=0.01), and drug regimen (p=0.001).Conclusions: The degree of prostate volume cytoreduction was positively associated with higher Gleason score and PPBs. Greater reductions in prostate volume may be an indicator of more aggressive cancer.

The comparison of ruthenium brachytherapy and simultaneous transpupillary thermotherapy of choroidal melanoma with brachytherapy alone

Andrey A. Yarovoy, Dzhavid A. Magaramov, Evgeniya S. Bulgakova — 2011-11-21

Abstract: Purpose: To compare the outcomes of combined treatment of choroidal melanoma with ruthenium brachytherapy (BT) simultaneously with transpupillary thermotherapy (TTT) and treatment with BT alone.Methods and Materials: Two matched groups of patients, one treated with BT and simultaneous TTT (Group BT+TTT, n=63), the other treated with BT alone (Group BT, n=70) were analyzed retrospectively. The main outcome measures were rate of tumor regression, recurrences, enucleations, metastases, recurrence-free and overall survival rate, and visual acuity, assessed by Kaplan–Meier analysis.Results: Patients were matched according to mean age (p=0.22), mean tumor thickness (6.4 vs. 6.25mm, range 2.5–10.8mm, p=0.59), and mean length of followup (42 vs. 34.4 months, range 3–109, p=0.052). Tumor largest basal diameter (13.0 vs. 12.9mm), tumor location, and mean radiation dose (apical 135 vs. 136Gy and scleral 1294 vs. 1438Gy) were also similar in both groups (p>0.1). Treatment with BT+TTT resulted in higher rate of tumor regression (63% vs. 49%, respectively, p=0.036), lower 5-year tumor recurrence rate (96% vs. 83%, p<0.034), and higher eye-globe preservation (98% vs. 87%, p<0.024) and recurrence-free survival rates (89% vs. 67%, p<0.017) than treatment with BT alone. There was no difference in complications (p>0.5), metastasis-free (93% vs. 81%, p>0.22) and overall survival rates (91% vs. 81%, p>0.39), or in visual outcomes.Conclusion: Combined treatment of choroidal melanoma with ruthenium BT and simultaneous TTT seems to provide higher local control, eye-globe preservation, and recurrence-free survival rates than treatment with BT alone and results in similar rates of metastases and overall survival.

Practical steps for establishing ocular plaque therapy in developing countries

2012-01-09

Abstract: Introduction: Retinoblastoma and uveal melanoma are the most common ocular tumors in children and adults, respectively. Enucleation and external beam radiation therapy are integral in the management of ocular tumors. However, these tumors could also be treated effectively by plaque therapy, which has the potential of preserving the globe and maintaining vision.Methods and materials: We reviewed our experience with the introduction of this technique to our center. Furthermore, we highlighted the critical role of a specialized multidisciplinary team in the successful implementation of this procedure.Discussion: This review represents a detailed report addressing the practical steps for successfully establishing plaque therapy in developing countries.Results: Plaque therapy was successfully implemented at our center in 1.5 years. Integration with an advanced cancer center is crucial for the correct transfer of this complex technology.Conclusion: Complex brachytherapy procedures could be successfully established and implemented in developing countries.

Monte Carlo calculations of AAPM Task Group Report No. 43 dosimetry parameters for the 125I I-Seed AgX100 source model

Firas Mourtada, Justin Mikell, Geoffrey Ibbott — 2011-08-04

Abstract: Purpose: The purpose of this study was to determine the dosimetric parameters of the AgX100, a new 125I brachytherapy seed model, using Monte Carlo (MC) simulations according to the protocol specified by the updated American Association of Physicists in Medicine Task Group No. 43 Report (TG-43U1) and compare these parameters with those of the established brachytherapy 125I seed models 6711 and I25.S06.Methods and Materials: Independent verification of the new seed geometry was performed using high-resolution digital radiography and scanning electron microscopy. MCNPX v.2.5 MC simulations of the AgX100 seed were performed to derive its TG-43U1 parameters, the dose rate constant, the radial dose function, and the two- and one-dimensional anisotropy functions in liquid water. A dosimetric error propagation analysis was also performed to include uncertainty because of seed manufacturing tolerances and physics parameters.Results: The MC-calculated dose rate constant for the AgX100 seed was 0.943cGy·h−1·U−1±2.6% (k=1) based on the air kerma strength for a simulated point detector. Tabulated results of the radial dose function for line and point source approximations and the two-dimensional anisotropy function are also reported.Conclusions: The MC-predicted dose distribution of the AgX100 seed was found to be comparable with that of the model 6711 seed but much different from the dose distribution of the model I25.S06 seeds. However, at shallow distances, there were some dosimetric differences between the AgX100 and 6711 seed, which warrant separate TG-43U1 parameters for use in clinical treatment planning systems.

Masthead

2012-05-01

Editorial Board

2012-05-01

Guide for Authors

2012-05-01

Brachytherapy

A comparison of brachytherapy techniques for partial breast irradiation

Three-dimensional image-based high-dose-rate interstitial brachytherapy for vaginal cancer

Inverse-planned gynecologic high-dose-rate interstitial brachytherapy: Clinical outcomes and dose–volume histogram analysis

Deaths within 12 months after 125I implantation for brachytherapy of prostate cancer: An investigation of radiation safety issues in Japan (2003–2010)

Globalization, implantation, cremation…Oh, my!

Rectal toxicity and rectal dosimetry in low-dose-rate 125I permanent prostate implants: A long-term study in 1006 patients

Biochemical and clinical experience with real-time intraoperatively planned permanent prostate brachytherapy

Relationship between prostate-specific antigen bounce body fat distribution and body mass index in permanent seed brachytherapy for prostate cancer

Higher percentage of positive biopsy cores and Gleason score are associated with a greater degree of prostate gland shrinkage after neoadjuvant cytoreductive therapy

The comparison of ruthenium brachytherapy and simultaneous transpupillary thermotherapy of choroidal melanoma with brachytherapy alone

Practical steps for establishing ocular plaque therapy in developing countries

Monte Carlo calculations of AAPM Task Group Report No. 43 dosimetry parameters for the 125I I-Seed AgX100 source model

Masthead

Table of Contents

Editorial Board

Guide for Authors