High-dose Rate Iridium-192 Brachytherapy Research Articles

High-Dose-Rate Brachytherapy for Treatment of Facial Skin Cancers: Local Control, Toxicity, and Quality of Life in 67 Patients.

While treatment of localized cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) is based on surgery, brachytherapy, which delivers a high dose of radiation to tumor tissue while sparing healthy tissue, is an alternative. Since the withdrawal of iridium wires from the market, brachytherapy has mainly been performed with high-dose-rate iridium-192 (HDR). This study evaluated the efficacy of HDR brachytherapy in terms of local control, survival, toxicity, and quality of life in patients with facial periorificial cutaneous SCC or BCC treated in our center between 2015 and 2021. Sixty-seven patients were treated for SCC (n = 49) or BCC (n = 18), on the nose (n = 29), lip (n = 28), eyelid (n = 7), or ear (n = 3). The majority had Tis or T1 tumors (73.1%). After a median follow-up of 28 months, 8 patients had a local recurrence. The local control rate at 3 years was 87.05% (95% CI 74.6-93.7). All patients developed grade 1-2 acute radio-mucositis or radiodermatitis and one experienced reversible grade 3 acute radio-mucositis. Of the 27 patients who completed the quality-of-life questionnaire, 77.8% recommended the treatment. This study confirms that HDR brachytherapy for facial cutaneous carcinomas provides good local control, good tolerance, and satisfactory functional outcome.

Total Reference Air Kerma (TRAK) is Associated with Dosimetric Parameters in Template-Based High Dose-Rate (HDR) Interstitial Brachytherapy in Advanced Gynecologic Cancers

To study TRAK and its association with dosimetric parameters in template-based high dose-rate interstitial brachytherapy in advanced gynecologic cancers. Brachytherapy treatment plans of 53 patients treated between 2012 and 2022 at our institution with template-based Iridium-192 HDR brachytherapy, post-external beam RT, for locally advanced cancers of the cervix and vagina were retrospectively reviewed. Brachytherapy dose ranged from 25 to 30-Gy delivered in 4 to 6 fractions. The median number of flexi-guide catheters implanted was 18 (range 10-30). Clinical Target Volume (CTV) values were mean (±SD): 72.2 (±40.4) cm3 (high-risk, HR) and 182.2 (±73.7) cm3 (intermediate-risk, IR) respectively. TRAK per fraction (cGy at 1m), dose-volume information for the implant, target, and organ-at-risk (OAR) were recorded. Indices for dose coverage (CI), homogeneity (DHI), non-uniformity (DNR), overdose volume (ODI) were computed. Regression and correlation tests were used to study the TRAK relationship with various dosimetric parameters. The false discovery rate at a 5% level was corrected using the Benjamini-Hochberg procedure. The average TRAK per fraction was 0.365 (±0.12) cGy. Mean and range values of plan quality indices were - CI 0.92 (0.7- 1.0), DHI 0.57 (0.41 - 0.77), DNR 0.43 (0.23 - 0.59) and ODI 0.22 (0.11 - 0.38), respectively Correlation results for TRAK with various dosimetric indices are presented in Table 1. TRAK showed a weak correlation with the number of flexi-guide catheters implanted (r = 0.35, p = 0.013). TRAK correlated strongly with target volumes (CTV_HR and CTV_IR and CTV_HR V100%) and with isodose volumes at both high (V300, V200, V150), and low dose levels (V90, V85, V50) (p<0.00001). TRAK correlated moderately with OAR 2-cm3 doses (p<0.00001). A weak correlation was observed between TRAK and plan quality indices. TRAK correlates positively with target volume and volumes enclosed by isodoses at various dose levels in interstitial HDR brachytherapy of advanced Gynecologic Cancers. Interestingly, our study observed a comparatively stronger positive correlation between TRAK and Sigmoid 2-cm3 dose, equated to TRAK correlation with bladder, rectum, and small bowel 2-cm3 doses. This finding could interest future studies utilizing TRAK as a surrogate for treatment outcome and toxicity.

The effects of bismuth oxide nanoparticles and cisplatin on MCF-7 breast cancer cells irradiated with Ir-192 High Dose Rate brachytherapy

Multimodal strategies of cancer treatment such as chemoradiotherapy aim to eradicate complex malignant diseases with enhanced therapeutic outcome. This study aimed to investigate the effects of bismuth oxide nanoparticles (BiONPs) and cisplatin (Cis) (BC) under gamma irradiation from Ir-192 of clinical High Dose Rate (HDR) brachytherapy. The cells irradiations were performed using 0.38 MeV Iridium-192 HDR Brachytherapy source with doses of 0–4 Gy in a single fraction. Apoptosis analyses were conducted using flow cytometry and subcellular biochemical changes were evaluated using Raman spectroscopy. The percentage of apoptosis of MCF-7 breast cancer cells with BC indicated an increment with early apoptosis were more predominant compared to late apoptotic cells. The cells population profile also shown cells shrinkage and cellular membrane damages for BC treated cells after brachytherapy. Subcellular biochemical changes were detected which involved the glycolysis process, the disarrangement of the amino acid structure and DNA/RNA disintegration that might be associated with cells death mechanism. This study demonstrated that the BiONPs-Cis (BC) can potentially enhanced radiation effects of brachytherapy due to the potent synergetic effects that will progressively enhance the therapeutic impact of cancer treatment.

Tumor control and cosmetic outcome of weekly iridium-192 high-dose-rate brachytherapy for nonmelanoma skin cancers in the elderly

PurposeRadiotherapy with high-dose-rate (HDR) brachytherapy is used to treat nonmelanoma skin cancers. We retrospectively analyzed a hypofractionated regimen to assess its safety and efficacy in elderly patients ≥70 years. Methods and MaterialsForty-eight patients with 67 lesions treated since 2016 with catheter-based iridium-192 HDR brachytherapy using a custom mold or three-dimensional–printed applicator met inclusion criteria. Treatment was 36 Gy in six weekly fractions. Local and locoregional control were assessed with Kaplan–Meier curves. Acute and late toxicity were graded as per Common Terminology Criteria for Adverse Events, version 5. Cosmesis was defined as “excellent” (indistinguishable from untreated skin), “good” (minimal changes), or “poor” (extensive changes). Univariate analyses were performed. ResultsMedian age was 85.7 years, and 21 were female. Durable local control occurred in 63 lesions (94.0%), giving estimated local control of 100% at 6 months, 95.1% at 1 year, and 88.8% at 2 years. No factors were predictive of local control on univariate analysis. All experienced acute toxicity that ultimately resolved: 28.4% Grade 2 and 4.5% Grade 3. Larger treatment volume receiving ≥36 Gy was associated with increased Grade ≥2 acute toxicity. Patients experienced late Grade 2 and late Grade 4 toxicity after 6.5% treatments each. Younger age was associated with increased Grade ≥2 late toxicity. “Good” or better cosmesis occurred in 93.2%, and “poor” cosmesis was associated with lower extremities and larger lesions. ConclusionsHypofractionated HDR brachytherapy using 36 Gy in six weekly fractions is associated with satisfactory locoregional control and cosmesis with minimal risk of severe acute or late toxicities.

Weekly High-Dose Rate Brachytherapy Via Surface Applicator For Non-Melanoma Skin Cancers In The Elderly

Among patients treated with brachytherapy for non-melanoma skin cancers (NMSCs), including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), there exists a wide variety in dose, fractionation, and schedules employed. We retrospectively analyzed a hypofractionated regimen delivering 36 Gy in 6 weekly fractions to assess its safety and efficacy for the treatment of NMSCs in the elderly. All elderly (> 70 years old) patients treated in 2016 to 2019 with follow-up were included. In total, 46 patients with 63 NMSC lesions were treated using iridium-192 high-dose rate brachytherapy (HDR) delivered with custom molds containing catheters to encompass the tumor or tumor bed with a margin. The dose scheme employed was a weekly hypofractionated regimen of 36 Gy in 6 weekly fractions. Only 7 lesions (11.1%) underwent a more extensive excision than a biopsy. Acute and late toxicity were graded as per CTCAE version 5. Cosmesis was graded as “excellent” (similar to surrounding untreated skin), “good” (minimal changes), or “poor” (extensive telangiectasia, ulceration, or scar tissue). Kaplan-Meier curves were used to assess local control. Median age at treatment initiation was 85.8 years (range: 71.2-98.7), and 20 patients (43.5%) were female. Performance statuses ranged from 0 to 4 with 30.4% ECOG 0-1, 41.3% ECOG 2, and 28.3% ECOG 3-4. Median time from first treatment to last was 35 days (range: 28-70), and median follow-up was 8.6 months (range: 1.3-35.9). 35 lesions (55.6%) were BCC, and most lesions (81.0%) were located on the head and neck, including 20 on the nose (31.7%). All patients experienced acute toxicity with grade 1 occurring in 66.7%, grade 2 in 28.6%, and grade 3 in 4.8%. Lesions were not evaluated during follow-up in 5 cases (7.9%), and grade ≥ 2 late or persistent toxicity occurred in 12.1%. Overall cosmetic outcome was determined to be “excellent” or “good” following 54 treatments (93.1% of evaluable lesions). There was a higher incidence of “poor” cosmesis for lesions located on the lower extremities (33.3% vs. 3.8%, p = 0.049) and larger lesions (median: 11.8 vs. 5.1 cc, p = 0.031). Recurrence occurred in 3 lesions (4.8%) with 1 BCC on the bridge of the nose experiencing failure 8 months after completing treatment and 2 SCC lesions exhibiting persistent disease initially thought to be a poor cosmetic outcome, 1 on the nasal ala (confirmed at 6 months) and 1 on the scalp vertex (confirmed at 18 months). Estimated local control was 100% at 6 months, 94.5% at 12 months, and 88.2% at 24 months. Five patients (10.9%) have died since completing treatment, none due to disease progression. Our results suggest a hypofractionated regimen consisting of 36 Gy in 6 weekly fractions delivered with high-dose rate brachytherapy via surface applicator represents both a safe and an effective treatment of non-melanoma skin cancers in elderly patients.

Radiosensitization Effects by Bismuth Oxide Nanoparticles in Combination with Cisplatin for High Dose Rate Brachytherapy.

PurposeThe aim of this study was to investigate the potential of the synergetic triple therapeutic combination encompassing bismuth oxide nanoparticles (BiONPs), cisplatin (Cis), and high dose rate (HDR) brachytherapy with Ir-192 source in breast cancer and normal fibroblast cell line.MethodsIn vitro models of breast cancer cell lines (MCF-7, MDA-MB-231) and normal fibroblast cell line (NIH/3T3) were employed. Cellular localization and cytotoxicity studies were conducted prior to inspection on the radiosensitization effects and generation of reactive oxygen species (ROS) on three proposed radiosensitizers: BiONPs, Cis, and BiONPs-Cis combination (BC). The optimal, non-cytotoxic concentration of BiONPs (0.5 mM) and the 25% inhibitory concentration of Cis (1.30 µM) were applied. The radiosensitization effects were evaluated by using a 0.38 MeV Iridium-192 HDR brachytherapy source over a prescribed dose range of 0 Gy to 4 Gy.ResultsThe cellular localization of BiONPs was visualized by light microscopy and accumulation of the BiONPs within the vicinity of the nuclear membrane was observed. Quantification of the sensitization enhancement ratio extrapolated from the survival curves indicates radiosensitization effects for MCF-7 and MDA-MB-231 when treated with BiONPs, Cis, and BC. However, NIH/3T3 cells exhibited contradictive behavior as it only reacted towards the BC combination. Nonetheless, the MCF-7 cell line loaded with BC shows the highest SER of 4.29. ROS production analysis, on the other hand, shows that Cis and BC radiosensitizers generated the highest free radicals in comparison to BiONPs alone.ConclusionA BiONPs-Cis combination was unveiled as a novel approach that offers promising radiosensitization enhancement that will increase the efficiency of tumor control while preserving the normal tissue at a reduced dose. This data is the first precedent to prove the synergetic implication of BiONPs, Cis, and HDR brachytherapy that will be beneficial for future chemoradiotherapy strategies in cancer care.

Excellent Long-term Breast Preservation Rate After Accelerated Partial Breast Irradiation Using a Balloon Device

BackgroundAccelerated partial breast irradiation (APBI) using a balloon device has been well tolerated. A recent retrospective population-based study showed an increase in the rate of subsequent mastectomy for patients who undergo APBI compared with whole breast radiation therapy. Our aim was to analyze the long-term results of patients treated with APBI at our institution to determine the salvage mastectomy and locoregional recurrence rates and cosmesis outcomes. Materials and MethodsAfter institutional review board approval, we conducted a retrospective review of 111 patients treated from June 2003 to October 2014 at our institution for early-stage breast cancer using a balloon device. After lumpectomy and nodal staging, the patients underwent APBI with high-dose rate iridium-192 brachytherapy. A computed tomography-based 3-dimensional plan was created, and a dose of 34 Gy in 10 fractions was given twice daily, 6 hours apart, over 5 days. Follow-up examinations were performed 2 to 3 times annually by either a surgeon and/or a radiation oncologist. Annual mammograms were obtained. The patients included postmenopausal women with node-negative early-stage invasive ductal carcinoma with a tumor size < 3 cm (n = 93) or ductal carcinoma in situ (n = 18). Cosmesis was evaluated using the Harvard criteria, as excellent, good, fair, or poor. ResultsAt a median follow-up period of 66 months (range, 1-139 months) after completing treatment, with a minimum of 5 years of follow-up data for 62 patients (55.9%), the incidence of ipsilateral breast tumor recurrence (IBTR) was 2.7% (n = 3) and the incidence of ipsilateral axilla nodal recurrence was 1.8% (n = 2). The ipsilateral breast preservation rate was 97.3%. The salvage mastectomy rate was 2.7% (n = 3), and the 5-year salvage mastectomy-free rate was 98.7% (95% confidence interval, 91.0%-99.8%). No distant failure developed, and no breast cancer-related deaths occurred. The 5-year overall survival rate was 91.7% (95% confidence interval, 83.2%-96.0%), and the 10-year breast cancer-specific survival rate was 100%. Of the 3 cases of IBTR, 2 were estrogen receptor negative (P = .076). The mean interval to IBTR was 78.7 ± 27.5 months from treatment completion. A significant association was noted between African-American ethnicity and IBTR (P = .0398). Excellent to good cosmesis was observed in 98.1% of the patients. The maximum skin dose (mean value) for patients with excellent, good, and fair cosmesis was 302.2 Gy, 315.4 Gy, and 372.5 Gy (88.9%, 92.7%, and 109.5% of the prescription dose), respectively. The maximum skin dose was < 340 Gy (100% of the prescribed dose) in 69.9% of patients with excellent to good cosmesis. ConclusionThe long-term follow-up data of patients receiving APBI with a balloon device showed a low salvage mastectomy rate with durable long-term breast preservation. Excellent local control with good cosmesis was noted in these postmenopausal patients treated with APBI.

Breast conservation therapy without capsular contracture in young augmented women using interstitial brachytherapy.

PurposeTo describe a breast-conserving technique using interstitial brachytherapy after lumpectomy and axillary nodal sampling in selected women who are diagnosed with breast cancer in the presence of augmentation mammoplasty.Material and methodsOver the past 20 years, we have developed and improved a technique of “pinch view” image-guided catheter insertion that avoids implant puncture. Selection criteria include: 1) women of any age with either subpectoral or retroglandular, augmentation implants (silicone or saline) who were diagnosed with stages Tis, T1, T2, N0, or N1 breast cancer; 2) any pathologic subtype of malignant breast cancer was accepted; 3) microscopic tumor extent ≤ 3 cm; 4) axillary node negative or metastasis to 1 to 3 nodes without extracapsular extension; and 5) surgical margins clear by the NSABP “no ink on tumor” definition. More than 250 women have been successfully treated. Patients were treated with high dose rate Iridium-192 brachytherapy to 34 Gy in 10 or 32 Gy in 8 twice daily fractions. The target volume was the surgical cavity edge with 1.5 to 2 cm margin using 3-D treatment planning systems.ResultsThe implant technique as currently employed is described. There have been no implant ruptures, and the Planning Treatment Volume (PTV-eval) exhibited at least 90% coverage by the 90% isodose line in the vast majority of cases. Dose Homogeneity Index exceeded 70% in most cases. The maximum skin dose was below the prescription dose in every case. Other than some patients with pre-existing capsular contracture, less than 5% experience new capsular contracture after interstitial brachytherapy.ConclusionsA technique of reliable and reproducible accelerated partial breast irradiation is described that minimizes the risk of capsular contracture by avoiding circumferential dose to the foreign body in the breast.

High-dose-rate brachytherapy with or without intensity modulated radiation therapy as salvage treatment for an isolated, gross local recurrence of prostate cancer post-prostatectomy

To evaluate the use of high-dose-rate (HDR) brachytherapy±intensity modulated radiation therapy (IMRT) as salvage therapy for patients with an isolated, gross local recurrence of prostate cancer after radical prostatectomy. Between October 2009 and May 2013, the authors treated six patients with salvage iridium-192 HDR brachytherapy±IMRT for biopsy-proven, recurrent prostate cancer post-prostatectomy. In each patient, a pelvic MRI scan or CT scan demonstrated a nodule (range 1.6, 4.7cm) in the prostate bed. Although prostate-specific antigen values were 0.2-9.5ng/mL at the time of salvage brachytherapy, there was no pelvic adenopathy on CT or MRI scan, and a bone scan was negative in all cases. Five patients were treated with IMRT to 4500-5040cGy in 25-28 fractions to the prostate bed followed by two 950cGy HDR brachytherapy fractions separated by 1-2weeks. A sixth patient underwent HDR brachytherapy monotherapy consisting of 3800cGy in four fractions over 3 days. Toxicities were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. Median followup was 9 months (range 3, 40 months). All six patients have been free of androgen deprivation therapy and have an undetectable prostate-specific antigen. One patient developed late Grade 2 urinary incontinence. There was no late grade ≥2 gastrointestinal toxicity. HDR brachytherapy±IMRT is a safe and effective salvage therapy option for an isolated, gross local recurrence of prostate cancer after radical prostatectomy and merits further study.

Intraoperative and percutaneous iridium-192 high-dose-rate brachytherapy for previously irradiated lesions of the spine

Advances in stereotactic radiosurgery have improved local control of spine metastases, but local failure is still a problem and repeat irradiation is limited by normal tissue tolerance. A novel high-dose-rate (HDR) brachytherapy technique has been developed to treat these previously irradiated lesions. Five patients with progressive disease at previously irradiated sites in the spine who were not amenable to further external beam radiation were treated. Catheters were placed intraoperatively in 2 patients and percutaneously implanted in 3 patients with image-guided techniques. Conformal plans were generated to deliver dose to target tissues and spare critical structures. Patients received single-fraction treatment using HDR iridium-192 brachytherapy. Median dose was 14 Gy (range, 12-18 Gy) with a median gross total volume D90 of 75% (range, 31-94%); spinal cord/cauda equina dose constraints were met. At a median followup of 9 months, no local progression of disease has been observed. Four patients had reduction in pain 1-4 weeks after treatment. No brachytherapy-related complications have been observed. Intraoperative and percutaneous iridium-192 HDR spine brachytherapy techniques were not associated with complications or acute toxicity. There has been no local progression at treated sites, and most patients experienced reduction in cancer-related pain.

A comparison of HDR near source dosimetry using a treatment planning system, Monte Carlo simulation, and radiochromic film

This study aimed to investigate the high-dose rate Iridium-192 brachytherapy, including near source dosimetry, of a catheter-based applicator from 0.5mm to 1cm along the transverse axis. Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter-based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the American Association of Physicists in Medicine Updated Task Group 43 (TG-43U1) dose calculation formalism. The difference between dose measured using radiochromic film along the transverse plane at 0.5mm from the surface and the predicted dose by the TPS was 24%±13%. The dose difference between the MC simulation along the transverse plane at 0.5mm from the surface and the predicted dose by the TPS was 22.1%±3%. For distances from 1.5mm to 1cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3%. The TPS under-predicts the dose at the surface of the applicator, i.e., 0.5mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15% of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS, and 7% of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3%.

Predicting biochemical tumor control after brachytherapy for clinically localized prostate cancer: The Memorial Sloan-Kettering Cancer Center experience

PurposeTo identify predictors of biochemical tumor control and present an updated prognostic nomogram for patients with clinically localized prostate cancer treated with brachytherapy. Methods and MaterialsOne thousand four hundred sixty-six patients with clinically localized prostate cancer were treated with brachytherapy alone or along with supplemental conformal radiotherapy. Nine hundred one patients (61%) were treated with Iodine-125 (125I) monotherapy to a prescribed dose of 144Gy, and 41 (4.5%) were treated with Palladium-103 (103Pd) monotherapy to a prescribed dose of 125Gy. In patients with higher risk features (n=715), a combined modality approach was used, which comprised 125I or 103Pd seed implantation or Iridium-192 high–dose rate brachytherapy followed 1–2 months later by supplemental intensity-modulated image-guided radiotherapy to the prostate. ResultsThe 5-year prostate-specific antigen relapse-free survival (PSA-RFS) outcomes for favorable-, intermediate-, and high-risk patients were 98%, 95%, and 80%, respectively (p<0.001). Multivariate Cox regression analysis identified Gleason score (p<0.001) and pretreatment PSA (p=0.04) as predictors for PSA tumor control. In this cohort of patients, the use of neoadjuvant and concurrent androgen deprivation therapy did not influence biochemical tumor control outcomes. In the subset of patients treated with 125I monotherapy, D90>140Gy compared with lower doses was associated with improved PSA-RFS. A nomogram predicting PSA-RFS was developed based on these predictors and had a concordance index of 0.70. ConclusionsResults with brachytherapy for all treatment groups were excellent. D90 higher than 140Gy was associated with improved biochemical tumor control compared with lower doses. Androgen deprivation therapy use did not impact on tumor control outcomes in these patients.

Clinical Results of Iridium-192 High Dose Rate Brachytherapy with External Beam Radiotherapy

Here, we report the clinical results of iridium-192 high dose rate brachytherapy at Kanazawa University Hospital. The study population consisted of 166 patients diagnosed with T1c-T3bN0M0 prostate cancer treated with high dose rate brachytherapy and external beam radiotherapy and followed up for 6 months or longer. Treatment consisted of external beam radiotherapy to the prostate at 44 Gy/22 fractions and high dose rate brachytherapy at 18 Gy/3 fractions. Median follow-up interval was 31.5 months (range 6.2-88.7). The overall 5-year biological recurrence-free survival rate was 93.0%. The 5-year biological recurrence-free survival rates for the patients in low-, intermediate- and high-risk groups according to the D'Amico risk classification criteria were 96.1%, 89.0% and 91.6%, respectively. When limited to the group that did not receive adjuvant hormonal therapy, the 5-year biological recurrence-free survival rates for the patients in low-, intermediate- and high-risk groups were 96.0%, 96.3% and 82.9%, respectively. Grade 3 or greater adverse effects were rare. Urethral stricture was observed in only 1.0% of the patients. Eighty percent of patients retained erectile function after high dose rate brachytherapy and reported satisfaction with sexual function. High dose rate brachytherapy is considered a good form of treatment for localized prostate cancer, although longer follow-up is necessary.

A dosimetric comparison of Xoft Axxent Electronic Brachytherapy and iridium-192 high-dose-rate brachytherapy in the treatment of endometrial cancer

Purpose This analysis was undertaken to dosimetrically compare iridium-192 high-dose-rate brachytherapy (IB) and Xoft Axxent Electronic Brachytherapy (XB; Xoft Inc., Sunnyvale, CA) in the treatment of endometrial cancer. Methods and Materials The planning CT scans from 11 patients previously treated with IB were used to construct hypothetical treatment plans using the source characteristics of the XB device. The mean V 95, V 100, and V 150 (percent of the planning target volume that received 95%, 100%, and 150% of the prescription dose) were calculated. For both the bladder and rectum, the V 35 (percent of the organ that received 35% of the prescription dose) and V 50 (percent of the organ that received 50% of the prescription dose) were calculated for each patient using both methods of vaginal brachytherapy. Results The mean % V 95 was 99.7% vs. 99.6% ( p = ns) and the mean % V 100 was 99.0% vs. 99.1% ( p = ns) for the IB and XB methods, respectively. The mean % V 150 was 35.8% vs. 58.9% ( p < 0.05) for the IB and XB methods, respectively. The mean bladder % V 35 was 47.7% vs. 27.4% ( p < 0.05) and the mean bladder % V 50 was 26.5% vs. 15.9% ( p < 0.05) for the IB and XB methods, respectively. The mean rectal % V 35 was 48.3% vs. 28.3% ( p < 0.05) and the mean rectal % V 50 was 27.8% vs. 17.0% ( p < 0.05) for the IB and XB methods, respectively. Conclusions The IB and XB methods of vaginal brachytherapy offer equivalent target volume coverage; however, the XB method allows increased sparing of the bladder and rectum.

Free vascularised tissue transfer and brachytherapy for soft-tissue sarcomas of the extremities

We reviewed the medical files of nine patients with localised soft-tissue sarcomas of the extremities treated with surgical resection, free vascularised tissue transfer, and computerised after-loading iridium-192 high dose rate brachytherapy over a period of 8 years. All patients had external beam radiation therapy in fractions with a total dose of 48-52 Gy, followed by surgery at approximately 4-5 weeks post-irradiation. Surgical treatment included wide resection of the primary tumour in six patients, and marginal resection in three patients. Microsurgical reconstruction of the soft-tissue defect used a free vascularised musculocutaneous flap that included the gracilis flap in five patients, the latissimus dorsi flap in four patients, and the radiovolar flap in one patient. Postoperative brachytherapy dose ranged from 12 to 24 Gy. Adjuvant chemotherapy was administered in five patients with large tumours and marginal resection. At a mean follow-up of 36 months, eight patients were still alive with no evidence of local recurrence or distant metastases; all these patients had good cosmetic and functional outcomes. Two patients died with lung metastases; one of these patients had local tumour recurrence. Wound healing problems and seroma formations were observed in two patients. Intramedullary nailing was required in one patient for a pathological fracture. Tumour resection for soft-tissue sarcomas combined with microsurgical reconstruction of the soft-tissue defect, preoperative external beam radiation and high dose rate brachytherapy results in a high degree of local control with acceptable complications.

Monte Carlo characterization of the M‐19 high dose rate Iridium‐192 brachytherapy source

The MCNP5 Monte Carlo code was used to simulate the dosimetry of an M-19 iridium-192 high dose rate brachytherapy source in both air/vacuum and water environments with the in-air photon spectrum filtered to remove low-energy photons below delta=10 keV. Dosimetric data was organized into an away-along table and was used to derive the updated AAPM Task Group Report No. 43 (TG-43U1) parameters including S(K), D(r, theta), lamda, gL(r), F(r, theta), phi an(r), and phi an, and their respective statistical uncertainties.

High dose-rate brachytherapy of prostate cancer utilising Iridium-192 after-loading technique: Technical and methodological aspects

The aim of this study was to focus on certain characteristic problems associated with Iridium-192 high dose-rate brachytherapy (Ir-192 HDR-BT) in combination with external beam radiation therapy (EBRT) in the treatment of patients with localised prostate cancer. Over a period of 16 years, >2,000 patients with prostate cancer have been treated in Sweden with a combination of two fractions of 10 Gy Ir-192 HDR-BT and 50 Gy of fractionated EBRT. Although this treatment is usually well tolerated, there are biological and technical factors to be considered before and during the treatment of the patient to avoid side effects or under-treatment of the target volume. Some of the problems facing the doctors are transducer stability, needle deviation, target definition, target motion, pubic arch interference, concomitant diseases and tolerance doses for different organs at risk. These problems are discussed and possible solutions are presented in this study.

Preliminary results and evaluation of MammoSite balloon brachytherapy for partial breast irradiation for pure ductal carcinoma in situ: a phase II clinical study

Background This report presents the preliminary results and evaluation of the MammoSite balloon catheter (MammoSite Radiation Therapy System; Cytyc Corporation, Marlboro, MA) as the sole method of delivering partial breast irradiation to the lumpectomy bed with breast-conserving surgery in patients with pure ductal carcinoma in situ (DCIS). Methods Twelve institutions are participating in this phase II clinical study. A total of 133 patients have been enrolled and 100 patients have successfully completed the prescribed radiation therapy. A dose of 34 Gy was delivered in 10 fractions over 5 days prescribed to 1 cm from the applicator surface using iridium-192 high-dose rate brachytherapy. Patients who met the following criteria were selected for enrollment into the study: age 45 years or older, unicentric pure DCIS, mammographic lesion of 3 cm or less, negative margins as defined by 1 mm or more, postoperative final gross pathologic size of tumor of 5 cm or less, clinically node negative, and a postlumpectomy mammogram showing the absence of any residual suspicious microcalcifications. The placement of the MammoSite catheter was performed either at the time of the lumpectomy or postlumpectomy. The minimum distance from the balloon surface to the surface of the skin is greater than 5 mm. Data collection points are at time of enrollment, time of implant, 3 months, 6 months, and then yearly at 1- to 5-year follow-up visits. Data collected are local control rates, cosmetic outcome using the Harvard Scale, toxicities, serious adverse events, disease-free survival, cause-specific survival, and contralateral breast failure. The Van Nuys Prognostic Index scores were calculated for each patient. Local recurrence is defined as either invasive or noninvasive recurrence within the target volume. Ipsilateral elsewhere recurrence is defined as either an invasive or noninvasive recurrence occurring outside of the target volume in the previously treated breast. This recurrence is classified as a new primary tumor. Results The mean follow-up period was 9.5 months (range, 1–24 mo). The MammoSite catheter was explanted for the following reasons: inadequate skin distance (5.1%; 6 of 117), poor cavity conformance (5.1%; 6 of 117), positive margins (2.6%; 3 of 117), final histology (.85%; 1 of 117), and physician decision (.85%; 1 of 117). Of the patients in whom the MammoSite was explanted because of skin spacing or cavity conformance, 50% were at sites of new users (institutions that have placed fewer than 10 Mammosite catheters). Cosmetic results were rated as excellent in 63%, good in 35%, and fair in 2% in the 86 patients with a follow-up visit. Two patients were diagnosed with an ipsilateral local recurrence, 1 outside of the target volume and 1 true recurrence/marginal miss. One patient was diagnosed at 8 months and the other was diagnosed at 11 months. Both of these ipsilateral failures were DCIS. The Van Nuys Prognostic Index of these 2 patients was 9 and 8, respectively. Data collected showed the mean age at placement was 60.8 y, mean tumor size was 10.6 mm, mean actual closest surgical margin was 6.8 mm (range, .1–40 mm), a re-excision rate of 35%, postlumpectomy placement was 71%, and the mean skin-to-balloon surface distance was 13 mm with 89% ≥7 mm. No serious adverse events were reported. The infection rate was 4.0%. Conclusions Accelerated partial breast irradiation delivered with the MammoSite balloon was clinically successful in patients entered into a phase II clinical study with pure DCIS, with results comparable with other studies reported in the literature that have evaluated use of the MammoSite balloon brachytherapy for delivery of radiation therapy in early breast cancers. Inadequate skin distance and poor cavity conformance were the main factors limiting the use of the MammoSite device. Cosmetic results were good to excellent in 98%. There have been 2 ipsilateral breast recurrences.

High Dose Rate Iridium-192 Brachytherapy as a Component of Radical Radiotherapy for the Treatment of Localised Prostate Cancer

Aims To assess the treatment outcomes and toxicity of conformal high dose rate (HDR) brachytherapy boost as a means of radiation dose escalation in patients with localised prostate cancer. Materials and methods Between December 1998 and July 2004, 65 consecutive patients with localised prostate cancer (magnetic resonance imaging-staged T1–3 N0 M0) were treated with external beam radiation therapy (EBRT) followed by two fractions of HDR iridium-192 brachytherapy. The patients selected this treatment modality in preference to entering an ongoing randomised phase 3 trial. Any pre-treatment serum prostate-specific antigen (PSA) and Gleason score were included. The primary end point was biochemical disease-free progression. Late treatment-related morbidity was graded according to the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer criteria. Results The median patient age was 67.3 years (range 47.9–80). Sixty patients (92.3%) had intermediate- to high-risk disease defined by clinical stage, presenting PSA and Gleason score/World Health Organisation (WHO) grade. With a median follow-up of 3.5 years (range 0.6–5.8), two patients had died of metastatic disease and another four patients had PSA relapse, giving a 3-year actuarial biochemical disease-free progression of 90.8%. Three patients (4.6%) had acute grade 3 genitourinary toxicity, in the form of urinary retention. Late grade 3 and 4 genitourinary toxicities occurred in four patients (6.2%) and one patient (1.5%), respectively. No late gastrointestinal toxicities were observed. Conclusions These results suggest that the combined modality of conformal HDR brachytherapy and EBRT is a feasible treatment modality with acceptable acute and late toxicities, comparable with those of EBRT alone. It offers an attractive conformal treatment modality with the potential of further dose escalation in the treatment of localised prostate cancer.

High-dose-rate brachytherapy combined with long-term hormonal therapy for high-risk prostate cancer: Results of a retrospective analysis

High-dose-rate (HDR) brachytherapy combined with hormonal therapy (HTx), without the addition of external beam radiation therapy (EBRT) for high-risk prostate cancer was evaluated retrospectively. Between May 1995 and April 2002, 35 patients with prostate cancer [Stage > or = T2b (UICC 1997) or tumor grading=3 or prostate-specific antigen (PSA) level > or = 20 ng/mL] were treated with HDR brachytherapy combined with HTx. Most patients (74%) had two or more of these factors. All patients received Iridium-192 HDR brachytherapy with a total dose of 54 Gy/9 fractions/5 days (48 Gy/8 fractions/5 days for the first 6 cases) in one implant session. The median neoadjuvant HTx [luteinizing hormone-releasing hormone (LH-RH) agonist and antiandrogen] period was 7 months. The median adjuvant HTx (ATH) (LH-RH agonist) period was 40 months, and median follow-up was 57 months (range, 23-117 months). The 5-year actuarial biochemical control, local control, and disease-free rates were 62%, 96%, and 76% respectively. No patients experienced local and/or regional relapse without distant progression. The 5-year actuarial cause-specific survival and overall survival rates were 89% and 87%, respectively. The acute and late toxicity were moderate and well tolerated. HDR brachytherapy plus long-term HTx is at least as effective as conventional EBRT plus long-term HTx.