Intraoperative radiation therapy with 50 kV x-rays: A multi-institutional review.

This report covers clinical implementation of a low kV intraoperative radiation therapy (IORT) program with the INTRABEAM® System (Carl Zeiss Meditec AG, Jena, Germany). Based on collective user experience from eight institutions, we discuss best methods of INTRABEAM quality assurance (QA) tests, commissioning measurements, clinical workflow, treatment planning, and potential avenues for research. The guide provides pertinent background information and clinical justification for IORT. It describes the INTRABEAM system and commissioning measurements along with a TG100 risk management analysis to ensure safety and accuracy of the IORT program. Following safety checks, dosimetry measurements are performed for verification of field flatness and symmetry, x-ray output, and depth dose. Also discussed are dose linearity checks, beam isotropy, ion chamber measurements, calibration protocols, and in-vivo dosimetry with optically stimulated luminescence dosimeters OSLDs, and radiochromic film. Emphasis is placed on the importance of routine QA procedures (daily, monthly, and annual) performed at regular intervals for a successful IORT program. For safe and accurate dose delivery, tests of important components of IORT clinical workflow are emphasized, such as, dose prescription, pre-treatment QA, treatment setup, safety checks, radiation surveys, and independent checks of delivered dose. Challenges associated with in-vivo dose measurements are discussed, along with special treatment procedures and shielding requirements. The importance of treatment planning in IORT is reviewed with reference to a Monte Carlo-based commercial treatment planning system highlighting its main features and limitations. The report concludes with suggested topics for research including CT-based image-guided treatment planning and improved prescription dose accuracy. We hope that this multi-institutional report will serve as a guidance document on the clinical implementation and use of INTRABEAM IORT.

Safety and efficacy of Cesium-131 brachytherapy for brain tumors.

BACKGROUND: The introduction of Cesium-131 (Cs-131) as a radiation source has led to a resurgence of brachytherapy for central nervous system (CNS) tumors. The aim of this study was to evaluate the safety and efficacy of the largest cohort of Cs-131 patients to-date. METHODS: A retrospective review of all CNS tumors treated with resection and adjuvant Cs-131 brachytherapy at New York-Presbyterian/Weill Cornell from 2010 to 2021 was performed. Overall survival (OS) and local control (LC) were assessed with Kaplan-Meier methodology. Univariable analysis was conducted to identify patient factors associated with local recurrence or radiation necrosis. RESULTS: Adjuvant Cs-131 brachytherapy following resection was performed in 119 patients with a median follow-up time of 11.8 (IQR 4.7-23.6) months and a mean of 22.3 +/-30.3 months. 1-year survival rates were 53.3% (95%CI 41.9-64.6%) for brain metastases (BrM), 45.9% (95%CI 24.8-67.0%) for gliomas, and 73.3% (95%CI 50.9-95.7%) for meningiomas. 1-year local control rates were 84.7% for BrM, 34.1% for gliomas, and 83.3% for meningiomas (p < 0.001). For BrM, local control was superior in NSCLC relative to other BrM pathologies (90.8% versus 76.5%, p = 0.039). Radiographic radiation necrosis (RN) was identified in 10 (8.4%) cases and demonstrated an association with smaller median tumor size (2.4 [IQR 1.8-2.7 cm] versus 3.1 [IQR 2.4-3.8 cm], p = 0.034). Wound complications occurred in 14 (11.8%) patients. CONCLUSIONS: Cs-131 brachytherapy demonstrated a favorable safety and efficacy profile characterized by high rates of local control for all treated pathologies. The concept of brachytherapy has seen a resurgence given the excellent results when Cs-131 is used as a source.

Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG-55.

The use of radiochromic film (RCF) dosimetry in radiation therapy is extensive due to its high level of achievable accuracy for a wide range of dose values and its suitability under a variety of measurement conditions. However, since the publication of the 1998 AAPM Task Group 55, Report No. 63 on RCF dosimetry, the chemistry, composition, and readout systems for RCFs have evolved steadily. There are several challenges in using the new RCFs, readout systems and validation of the results depending on their applications. Accurate RCF dosimetry requires understanding of RCF selection, handling and calibration methods, calibration curves, dose conversion methods, correction methodologies as well as selection, operation and quality assurance (QA) programs of the readout systems. Acquiring this level of knowledge is not straight forward, even for some experienced users. This Task Group report addresses these issues and provides a basic understanding of available RCF models, dosimetric characteristics and properties, advantages and limitations, configurations, and overall elemental compositions of the RCFs that have changed over the past 20 yr. In addition, this report provides specific guidelines for data processing and analysis schemes and correction methodologies for clinical applications in radiation therapy.

Characterization of Recurrences Following Second Breast-Conserving Surgery with Intraoperative Radiotherapy.

BACKGROUND: Breast-conserving surgery with breast re-irradiation is an emerging technique in the treatment of selected cases of locally recurrent breast cancer. Further information is needed to characterize factors that may select for an appropriate patient population for this treatment approach. METHODS: We report herein a single-institution retrospective analysis of patients with ipsilateral breast cancer recurrence treated with a second breast-conserving therapy with intraoperative radiotherapy. Patient records were reviewed to analyze toxicity, further recurrence, and characteristics of recurrent patients following this treatment approach. RESULTS: We included 57 patients in the analysis. At median follow-up of 24.5 months, ipsilateral breast tumor recurrence occurred in six patients (11%), four of which localized to the quadrant of the initial recurrent disease and two of which recurred elsewhere in the treated breast. Locoregional control was 89%, and disease-free survival was 81%. Only one patient was found to have grade 3 or greater toxicity. CONCLUSION: A second breast-conserving surgery with intraoperative radiotherapy is tolerable with acceptable toxicity for patients with locally recurrent disease refusing mastectomy. Prospective clinical trials are needed to define the subset of patients who may be appropriate for this treatment approach as an alternative to mastectomy.

Accelerated Hypofractionated Radiotherapy in the Era of Concurrent Temozolomide Chemotherapy in Elderly Patients with Glioblastoma Multiforme.

Introduction Patients with glioblastoma multiforme (GBM) over age 65 represent nearly half of those diagnosed per annum. They have a different tumor markers profile, physiologic reserve, and a median survival as low as three to four months. An optimal treatment strategy in older GBM patients remains undefined, with many patients receiving radiation in 30 treatments over six weeks, a regimen based on trials originally excluding patients over age 70. Recent studies have suggested reducing the number of treatments to 10-15 over two to three weeks with similar efficacy. We present an elderly population of patients treated with six radiation treatments. Methods After IRB approval, we reviewed the electronic medical records of 20 consecutive patients over the age 60 at diagnosis with GBM, treated with maximally safe neurosurgical resection, and adjuvant hypofractionated radiation (HFRT) and temozolomide (TMZ) between 2012 and 2015. HFRT was given every other weekday for two weeks, in a total of six fractions (6 × 6 Gy to contrast-enhancing tumor +5 mm and 6 × 4 Gy to fluid-attenuated inversion recovery (FLAIR) +2 cm) with concurrent TMZ (75 mg/m2 daily), followed by adjuvant TMZ (150-200 mg/m2 in 5/28 days). The response was assessed using the Macdonald and Revised Assessment in Neuro-Oncology (RANO) criteria, radiology reports, physician notes, and tumor board consensus notes. Descriptive statistics, overall survival (OS), progression-free survival (PFS), toxicity, and steroid use were calculated and compared to the historical controls of patients treated with a six-week radiation regimen of 60 Gy in 30 fractions with TMZ.   Results The median age at diagnosis was 70.5 years (range: 61 - 82 years). Median pre-radiation Karnofsky performance scale (KPS) was 60 (range: 40 - 90). The median preoperative maximum gross tumor diameter on MRI was 3.6 cm (range: 1.8 - 6 cm). Six patients (30%) had a gross total resection (GTR), eight (40%) had a subtotal resection (STR), and six (30%) had biopsy only. The median progression-free survival was five months (95% (confidence interval) CI: 2.8, 16.4) and median OS of 14 months (95% CI: 5.0, upper limit not estimable). Of the 19 patients tested for isocitrate dehydrogenase-1 (IDH), 100% were negative. Of the eight patients who had MGMT methylation status results, four (50%) were positive for O6-methylguanine-DNA methyltransferase (MGMT) methylation. In the 18 patients who completed radiation, the HFRT treatment was well tolerated without any Grade 3/4 acute toxicities. Conclusions The accelerated adjuvant course of HFRT with TMZ used for the elderly with GBM decreases radiation treatment days to six. It was well tolerated in patients over 60 years of age and provided similar OS, PFS, minimal toxicity, and decreased steroid usage compared to historical controls treated with six or even two to three weeks of radiotherapy.

Clinical Outcomes of Large Brain Metastases Treated With Neurosurgical Resection and Intraoperative Cesium-131 Brachytherapy: Results of a Prospective Trial.

PURPOSE: Studies on adjuvant stereotactic radiosurgery to the cavity of resected brain metastases have suggested that larger tumors (>2.0 cm) have greater rates of recurrence and radionecrosis (RN). The present study assessed the effect of permanent low-dose 131Cs brachytherapy on local control and RN in patients treated for large brain metastases. METHODS AND MATERIALS: After institutional review board approval, 42 patients with 46 metastases ≥2.0 cm in preoperative diameter were accrued to a prospective trial from 2010 to 2015. Patients underwent surgical resection with intraoperative placement of stranded 131Cs seeds as permanent volume implants in the resection cavity. The primary endpoint was local freedom from progression (FFP). Secondary endpoints included regional and distant FFP, overall survival (OS), and RN rate. Failures 5 to 20 mm from the cavity and dural-based failures were considered regional. A separate analysis was performed for metastases >3.0 cm. RESULTS: Of the 46 metastases, 18 were >3.0 cm in diameter. The median follow-up period was 11.9 months (range 0.6-51.9). The metastases had a median preoperative diameter of 3.0 cm (range 2.0-6.8). The local FFP rate was 100% for all tumor sizes. Regional recurrence developed in 3 of 46 lesions (7%), for a 1-year regional FFP rate of 89% (for tumors >3.0 cm, the FFP rate was 80%, 95% confidence interval 54%-100%). Distant recurrences were found in 19 of 46 lesions (41%), for a 1-year distant FFP rate of 52%. The median OS was 15.1 months, with a 1-year OS rate of 58%. Lesion size was not significantly associated with any endpoint on univariate or multivariate analysis. Radioresistant histologic features resulted in worse survival (P=.036). No cases of RN developed. CONCLUSIONS: Intraoperative 131Cs brachytherapy is a promising and effective therapy for large brain metastases requiring neurosurgical intervention, which can offer improved local control and lower rates of RN compared with stereotactic radiosurgery to the resection cavity.

Radiation Exposure and Safety Precautions Following 131Cs Brachytherapy in Patients with Brain Tumors.

Cesium-131 (Cs) brachytherapy is a safe and convenient treatment option for patients with resected brain tumors. This study prospectively analyzes radiation exposure in the patient population who were treated with a maximally safe neurosurgical resection and Cs brachytherapy. Following implantation, radiation dose rate measurements were taken at the surface, 35 cm, and 100 cm distances. Using the half-life of Cs (9.69 d), the dose rates were extrapolated at these distances over a period of time (t = 30 d). Data from dosimetry badges and rings worn by surgeons and radiation oncologists were collected and analyzed. Postoperatively, median dose rate was 0.2475 mSv h, 0.01 mSv h, and 0.001 mSv h and at 30 d post-implant, 0.0298 mSv h, 0.0012 mSv h, and 0.0001 mSv h at the surface, 35 cm, and 100 cm, respectively. All but one badge and ring measured a dose equivalent corresponding to ~0 mSv h, while 1 badge measured 0.02/0.02/0.02 mSv h. There was a significant correlation between the number of seeds implanted and dose rate at the surface (p = 0.0169). When stratified by the number of seeds: 4-15 seeds (n = 14) and 20-50 seeds (n = 4) had median dose rates of 0.1475 mSv h and 0.5565 mSv h, respectively (p = 0.0015). Using National Council on Radiation Protection guidelines, this study shows that dose equivalent from permanent Cs brachytherapy for the treatment of brain tumors is limited, and it maintains safe levels of exposure to family and medical personnel. Such information is critical knowledge for the neurosurgeons, radiation oncologists, nurses, hospital staff, and family as this method is gaining nationwide popularity.

Cesium-131 brachytherapy for recurrent brain metastases: durable salvage treatment for previously irradiated metastatic disease.

OBJECTIVE Managing patients whose intraparenchymal brain metastases recur after radiotherapy remains a challenge. Intraoperative cesium-131 (Cs-131) brachytherapy performed at the time of neurosurgical resection may represent an excellent salvage treatment option. The authors evaluated the outcomes of this novel treatment with permanent intraoperative Cs-131 brachytherapy. METHODS Thirteen patients with 15 metastases to the brain that recurred after stereotactic radiosurgery and/or whole brain radiotherapy were treated between 2010 and 2015. Stranded Cs-131 seeds were placed as a permanent volume implant. Prescription dose was 80 Gy at 5-mm depth from the resection cavity surface. The primary end point was resection cavity freedom from progression (FFP). Resection cavity freedom from progression (FFP), regional FFP, distant FFP, median survival, overall survival (OS), and toxicity were assessed. RESULTS The median duration of follow-up after salvage treatment was 5 months (range 0.5-18 months). The patients' median age was 64 years (range 51-74 years). The median resected tumor diameter was 2.9 cm (range 1.0-5.6 cm). The median number of seeds implanted was 19 (range 10-40), with a median activity per seed of 2.25 U (range 1.98-3.01 U) and median total activity of 39.6 U (range 20.0-95.2 U). The 1-year actuarial local FFP was 83.3%. The median OS was 7 months, and 1-year OS was 24.7%. Complications included infection (3), pseudomeningocele (1), seizure (1), and asymptomatic radionecrosis (RN) (1). CONCLUSIONS After failure of prior irradiation of brain metastases, re-irradiation with intraoperative Cs-131 brachytherapy implants provides durable local control and limits the risk of RN. The authors' initial experience demonstrates that this treatment approach is well tolerated and safe for patients with previously irradiated tumors after failure of more than 1 radiotherapy regimen and that it results in excellent response rates and minimal toxicity.

Analysis of stereotactic radiation vs. wedge resection vs. wedge resection plus Cesium-131 brachytherapy in early stage lung cancer.

PURPOSE: The purpose of the study was to evaluate the outcomes for wedge resection (WR), WR plus brachytherapy (WRB), or stereotactic body radiation therapy (SBRT) for early stage non-small lung cancer. METHODS AND MATERIALS: Retrospectively collected data of patients treated with WR, WRB, or SBRT (1993-2012). Cesium-131 (Cs131) used in WRB group in patients with close or positive margins based on surgical assessment. Kaplan-Meier survival analysis, log-rank test used to compare disease-free survival/overall survival between different groups. Multivariable analysis, using Cox proportional hazards regression analysis, was performed to evaluate the independent effect of age, gender, and treatment procedure on disease-free survival. RESULTS: A total of 272 patients were included in the study (123 WR, 52 WR+Cs-131, 97 SBRT). Cs-131 was used with WRs that the surgeons deemed high risk. Local control (LC) was similar in the three groups and was achieved in 92.2% for WR group vs. 96.2% for WR+Cs-131 and 95.5% for SBRT (p = 0.60). On multivariate analysis, although females showed a higher LC, neither LC nor distant metastasis were associated with age or gender (p = 0.65 and p = 0.41, respectively). Five-year overall survival was 100% in the WR+B group, 97.7% in the WR group, and 89.6% in the SBRT group (p = 0.02). Toxicity was similar in the three groups. CONCLUSION: WR, WR+ Cs-131, or SBRT are all excellent treatment options for patients with early stage non-small cell lung cancer that are not candidates for lobectomy. For high risk WRs, we favor use of Cesim-131 brachytherapy. Until a prospective randomized comparative study is done to evaluate the best treatment approach for early stage NSCLC, treatment selection should be based on a multidisciplinary team approach.

Cesium-131 brachytherapy in high risk and recurrent head and neck cancers: first report of long-term outcomes.

PURPOSE: The feasibility and efficacy of re-irradiation using contemporary radiation techniques to treat recurrent head and neck cancer has been demonstrated but the role of brachytherapy is unclear. Here we describe the use of (131)Cs brachytherapy with concurrent salvage surgery in 18 patients. MATERIAL AND METHODS: Eligible patients underwent maximal gross resection of the tumor with implantation of brachytherapy seeds delivering a minimum dose of 80 Gy to the tumor bed. Rates of overall survival, locoregional progression free survival, disease-free survival, and radiation-induced toxicity were analyzed. RESULTS: Retrospective Kaplan-Meier analysis shows median overall survival was 15 months and disease free survival was 12 months. Two patients developed grade 3 toxicity; all other complications were grade 1-2 with no grade 4 or 5 complications. CONCLUSIONS: Compared to prior literature, our study shows comparable rates of survival with a decreased rate of radiation-induced toxicity.

Phase I/II study of resection and intraoperative cesium-131 radioisotope brachytherapy in patients with newly diagnosed brain metastases.

OBJECT: Resected brain metastases have a high rate of local recurrence without adjuvant therapy. Adjuvant whole-brain radiotherapy (WBRT) remains the standard of care with a local control rate > 90%. However, WBRT is delivered over 10-15 days, which can delay other therapy and is associated with acute and long-term toxicities. Permanent cesium-131 ((131)Cs) implants can be used at the time of metastatic resection, thereby avoiding the need for any additional therapy. The authors evaluated the safety, feasibility, and efficacy of a novel therapeutic approach with permanent (131)Cs brachytherapy at the resection for brain metastases. METHODS: After institutional review board approval was obtained, 24 patients with a newly diagnosed metastasis to the brain were accrued to a prospective protocol between 2010 and 2012. There were 10 frontal, 7 parietal, 4 cerebellar, 2 occipital, and 1 temporal metastases. Histology included lung cancer (16), breast cancer (2), kidney cancer (2), melanoma (2), colon cancer (1), and cervical cancer (1). Stranded (131)Cs seeds were placed as permanent volume implants. The prescription dose was 80 Gy at a 5-mm depth from the resection cavity surface. Distant metastases were treated with stereotactic radiosurgery (SRS) or WBRT, depending on the number of lesions. The primary end point was local (resection cavity) freedom from progression (FFP). Secondary end points included regional FFP, distant FFP, median survival, overall survival (OS), and toxicity. RESULTS: The median follow-up was 19.3 months (range 12.89-29.57 months). The median age was 65 years (range 45-84 years). The median size of resected tumor was 2.7 cm (range 1.5-5.5 cm), and the median volume of resected tumor was 10.31 cm(3) (range 1.77-87.11 cm(3)). The median number of seeds used was 12 (range 4-35), with a median activity of 3.82 mCi per seed (range 3.31-4.83 mCi) and total activity of 46.91 mCi (range 15.31-130.70 mCi). Local FFP was 100%. There was 1 adjacent leptomeningeal recurrence, resulting in a 1-year regional FFP of 93.8% (95% CI 63.2%-99.1%). One-year distant FFP was 48.4% (95% CI 26.3%-67.4%). Median OS was 9.9 months (95% CI 4.8 months, upper limit not estimated) and 1-year OS was 50.0% (95% CI 29.1%-67.8%). Complications included CSF leak (1), seizure (1), and infection (1). There was no radiation necrosis. CONCLUSIONS: The use of postresection permanent (131)Cs brachytherapy implants resulted in no local recurrences and no radiation necrosis. This treatment was safe, well tolerated, and convenient for patients, resulting in a short radiation treatment course, high response rate, and minimal toxicity. These findings merit further study with a multicenter trial.

Lung-conserving treatment of a pulmonary oligometastasis with a wedge resection and 131Cs brachytherapy.

PURPOSE: Soft-tissue sarcomas most frequently metastasize to the lung. Surgical resection of pulmonary metastases is the primary treatment modality. Although lobectomy is widely acknowledged as the standard procedure to treat primary pulmonary tumors, the standard for pulmonary metastases is not well defined; furthermore, compromised lung function may tip the scales in favor of a less invasive approach. Here, we report the results of a patient treated with wedge resection and intraoperative cesium-131 ((131)Cs). METHODS AND MATERIALS: A 58-year-old African American female was diagnosed with the American Joint Committee on Cancer Stage IIA mixed uterine leiomyosarcoma and underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy followed by adjuvant external beam radiotherapy to a total dose of 45 Gy and vaginal brachytherapy to a total dose of 20 Gy. At 2 years, a routine CT scan of the chest revealed metastasis to right upper lobe of the lung. The patient's poor pulmonary function, related to a 45 pack-year smoking history and chronic emphysema, precluded a lobectomy. RESULTS: After the patient underwent a lung-sparing wedge resection of the pulmonary right upper lobe metastasis and intraoperative brachytherapy with (131)Cs seeds to a total dose of 80 Gy, she remained disease free in the implanted area. At a 2-year followup, imaging continued to reveal 100% local control of the area treated with wedge resection and intraoperative (131)Cs brachytherapy. The patient had no complications from this treatment. CONCLUSIONS: Such treatment approach may become an attractive option in patients with oligometastatic disease and compromised pulmonary function.

Role of isotope selection in long-term outcomes in patients with intermediate-risk prostate cancer treated with a combination of external beam radiotherapy and low-dose-rate interstitial brachytherapy.

OBJECTIVE: To examine the rates of long-term biochemical recurrence-free survival (BRFS) with respect to isotope in intermediate-risk prostate cancer treated with external beam radiotherapy (EBRT) and brachytherapy. METHODS: A total of 242 consecutive patients with intermediate-risk prostate cancer were treated with iodine-125 ((125)I) or palladium-103 ((103)Pd) implants after EBRT (range 45.0-50.4 Gy) from 1996 to 2002. Of the 242 patients, 119 (49.2%) were treated with (125)I and 123 (50.8%) with (103)Pd. Multivariate Cox regression analysis was used to analyze BRFS, defined according to the Phoenix definition (prostate-specific antigen nadir plus 2 ng/mL) with respect to Gleason score, stage, pretreatment prostate-specific antigen level, and source selection. Late genitourinary/gastrointestinal toxicities were assessed using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale. RESULTS: At a median follow-up of 10 years, the BRFS rate was 77.3%. A statistically significant difference was found in the 10-year BRFS rate between the (125)I- and (103)Pd-treated groups (82.7% and 70.6%, respectively; P = .001). The addition of hormonal therapy did not improve the 10-year BRFS rate (77.6%) compared with RT alone (77.1%; P = .22). However, a statistically significant difference in the BRFS rate was found with the addition of hormonal therapy to (103)Pd, improving the 10-year BRFS rate for (73.8%) compared with (103)Pd alone (69.1%; P = .008). On multivariate analysis, isotope type ((103)Pd vs (125)I), pretreatment prostate-specific antigen level >10 ng/mL, and greater tumor stage increased the risk of recurrence by 2.6-fold (P = .007), 5.9-fold (P < .0001), and 1.7-fold (P = .14), respectively. CONCLUSION: (125)I renders a superior rate of BRFS compared with (103)Pd when used with EBRT. Hormonal therapy does not provide additional benefit in patients with intermediate-risk prostate cancer treated with a combination of EBRT and brachytherapy, except for the addition of hormonal therapy to (103)Pd.

Management of single malignant lung nodules in elderly patients (70 years or older) who are not candidates for lobectomy.

PURPOSE: The aim of this study was to evaluate and compare sublobar resection plus intraoperative seed implant (IOS) versus stereotactic body radiation therapy (SBRT) in patients with single malignant lung nodules in patients 70 years of age or older. MATERIALS AND METHODS: A retrospective chart review was performed and 47 patients with adequate information were selected for analysis. Thirty patients with single malignant lung nodules received SBRT. Seventeen patients received limited surgical resection plus radioactive seed implantation for solitary malignant lung nodules. Univariate statistical analysis showed a significant difference only for the age in the 2 groups: the mean age in the radioactive seed group, 78.8 years versus 76.1 years in the SBRT group (2-sided, P=0.05). RESULTS: There was high local control and minimal toxicity with either treatment modality and no significant difference among the 2 groups in terms of local control, survival, and toxicity. However, the distant failure was higher but not statistically significant in the SBRT group (9 of 30 patients in SBRT vs. 0 of 17 in IOS, P=0.1). CONCLUSIONS: Our study has shown excellent outcomes and limited toxicity in both IOS and SBRT for treatment of single malignant lung nodules in patients who are not candidates for lobectomy. However, a randomized trial is needed in this group of elderly patients to determine the most appropriate treatment.

Cesium-131 permanent seed brachytherapy: dosimetric evaluation and radiation exposure to surgeons, radiation oncologists, and staff.

PURPOSE: Cesium-131 ((131)Cs) radioactive seed is Food and Drug Administration approved for permanent seed implant for all cancers, including lung and head and neck (HN) cancers. We describe the first clinical report of (131)Cs dosimetry and exposure rates to treating physicians and staff. METHODS AND MATERIALS: Twenty-eight patients received (131)Cs implant for early stage lung and recurrent HN cancers. A nomogram was developed to calculate the number of seeds needed to cover the wedge line with the prescription dose (80 Gy). Final dosimetry was obtained after CT planning a few days following the surgical procedure. Radiation exposure to the treating physicians and staff was measured at the completion of the procedure. RESULTS: A nomogram was developed using the variseed software with source data from American Association of Physicists in Medicine TG-43 report. The total volume covered by the prescription isodose line of (131)Cs was measured and compared with (125)I. The prescription volume was smaller for (131)Cs. In addition, the exposure rate with (131)Cs was found to be acceptable. CONCLUSION: Our preliminary experience with (131)Cs lung and HN brachytherapy has been very encouraging with excellent dosimetric coverage and acceptable exposure to the treating physicians and staff.

Morphea as a consequence of accelerated partial breast irradiation.

Morphea is a localized form of scleroderma usually unaccompanied by the typical systemic stigmata that characterize progressive systemic scleroderma. It rarely manifests at the site of whole breast external-beam radiation therapy. We present an unusual case of radiation-induced morphea (RIM) that occurred after accelerated partial breast irradiation (APBI) using intracavitary Contura brachytherapy. A 65-year-old white woman was treated for stage IIA invasive ductal carcinoma of the left breast with APBI to a dose of 34 Gy in 3.4-Gy fractions twice daily over the course 5 days with intracavitary brachytherapy. At 1.5 years after completion of APBI, the patient developed an area of tenderness, erythema, and induration at the site of irradiation. A skin biopsy was consistent with morphea. To our knowledge, this is the first case of RIM confined to the area of APBI.

Limited resection followed by intraoperative seed implantation is comparable to stereotactic body radiotherapy for solitary lung cancer.

BACKGROUND: The objective of this study was to compare the outcomes of patients who underwent wedge resection plus intraoperative brachytherapy versus patients who received stereotactic body radiotherapy (SBRT) for single malignant lung nodules. METHODS: A retrospective chart review included 55 patients who were treated for single lung nodules, and 47 of those patients who had adequate information were chosen for the current analysis. Twenty-five patients with single malignant lung nodules received SBRT. Twenty-two patients underwent limited surgical resection plus radioactive seed implantation for solitary malignant lung nodules. RESULTS: Univariate statistical analysis demonstrated a significance difference only for age in the 2 groups: The mean age in the radioactive seed group (66.6 years) was statistically significantly different from the mean of the age in the SBRT group (75.9 years; 2-sided P=.04). No significant differences were observed between the 2 groups in terms of local control, distant metastasis, survival, or toxicity. CONCLUSIONS: The current results demonstrated comparable efficacy in outcome and toxicity between surgical resection with radioactive seed implantation and SBRT for the treatment of single malignant lung nodules in patients who were not candidates for lobectomy/pneumonectomy.

Feasibility and safety of GliaSite brachytherapy in treatment of CNS tumors following neurosurgical resection.

PURPOSE: To investigate feasibility and safety of GliaSite brachytherapy for treatment of central nervous system (CNS) tumors following neurosurgical resection. We report mature results of long-term follow-up, outcomes and toxicity. MATERIALS AND METHODS: In the period from 2004 to 2007, 10 consecutive adult patients with recurrent, newly diagnosed, and metastatic brain malignancies underwent GliaSite brachytherapy following maximally safe neurosurgical resection. While 6/10 (60%) patients were treated for recurrence, having previously been treated with external beam radiotherapy (EBRT), 4/10 (40%) received radiotherapy (RT) for the first time. A median dose of 52.0 Gy (range, 45.0 - 60.0 Gy) was prescribed to 0.5 cm - 1.0 cm from the balloon surface. Radiation Therapy Oncology Group (RTOG) criteria were used to assess toxicities associated with this technique. Follow-up was assessed with MRI scans and was available on all enrolled patients. RESULTS: Median follow-up was 38 months (range, 18 - 57 months). Mean size of GliaSite balloon was 3.4 cm (range, 2.0 - 4.0 cm). Median survival was 14.0 months for the entire cohort after the treatment. The 17.6 and 16.0 months average survival for newly diagnosed and recurrent high grade gliomas (HGG), respectively, translated into a three-month improvement in survival in patients with newly diagnosed HGG compared to historical controls (P = 0.033). There were no RTOG grades 3 or 4 acute or late toxicities. Follow-up magnetic resonance imaging (MRI) imaging did not identify radiation necrosis. CONCLUSIONS: Our data indicate that treatment with GliaSite brachytherapy is feasible, safe and renders acceptable local control, acute and long-term toxicities. We are embarking on testing larger numbers of patients with this treatment modality.

The role of dose escalation with intracavitary brachytherapy in the treatment of localized CNS malignancies: outcomes and toxicities of a prospective study.

PURPOSE: This single-institution prospective study was designed to investigate the feasibility and safety of dose escalation with GliaSite (Proxima Therapeutics Inc., Alpharetta, GA) brachytherapy for the treatment of patients with newly diagnosed and recurrent central nervous system (CNS) tumors after neurosurgical resection. We now report mature results of this trial, its outcomes, and a toxicity profile. METHODS AND MATERIALS: Ten adult consecutive patients with recurrent and newly diagnosed CNS malignancies underwent GliaSite brachytherapy after maximally safe neurosurgical resection between 2004 and 2007. GliaSite balloon was placed intraoperatively, and the size was selected so as to conform to the surgical cavity. Low-dose-rate radiation was delivered with an aqueous solution of organically bound (125)I (Iotrex: sodium 3-((125)I)-iodo-4-hydroxybenzenesulfonate; Proxima Therapeutics Inc.), introduced into the balloon portion of the device via a subcutaneous port. Two to 3 weeks later, the device was filled with Iotrex for a median dwell time of 94.3 hours (range, 68.0-120.5 hours), after which the balloon was explanted. A commercial 3-D planning system was used for a detailed analysis of dosimetry. Median dose of 52.0 Gy (range, 45.0-60.0 Gy) was prescribed 0.5-1.0 cm from the balloon surface. Radiation Therapy Oncology Group (RTOG) criteria were used to assess acute and long-term toxicities associated with this technique. Followup was assessed with MRI scans and was available on all enrolled patients. RESULTS: Median followup for surviving patients was 38 months (range, 18-57 months). Mean size of GliaSite balloon was 3.4 cm (range, 2.0-4.0 cm). Mean volume of filling was 19.0 cc (range, 4.0-35.0 cc). Median activity of Iotrex was 301.6 mCi (range, 95.0-515.4 mCi). Median survival was 14.0 months for the entire cohort after the treatment with the GliaSite device. Of our cohort, 6/10 (60%) patients sustained recurrence (20% local and 40% distant). Median time to recurrence after treatment with GliaSite was 8.0 months, and median time to death after recurrence was 7.5 months. There were no RTOG Grade 3 or 4 acute or late toxicities. Followup MRI imaging did not identify any evidence of radiation necrosis. CONCLUSIONS: Our data indicate that treatment with GliaSite balloon brachytherapy is feasible and safe, while rendering acceptable local control and minimal acute and long-term toxicities for newly diagnosed and recurrent CNS malignancies. These encouraging results compel us to embark on testing larger numbers of patients with this treatment modality.