Additional External Beam Radiotherapy Research Articles

Retrospective analysis of tooth extraction and osteoradionecrosis after low-dose rate brachytherapy for patients with tongue cancer.

This study aimed to investigate the incidence of osteonecrosis of the jawbones (ORN) after tooth extraction in patients undergoing low-dose rate brachytherapy (LDR-BT) and assess its safety. This study retrospectively analyzed 145 patients with tongue cancer treated at Hiroshima University Hospital from 2007 to 2021 with LDR-BT using 192Ir or 198Au alone, LDR-BT and external beam radiotherapy (EBRT) with or without chemotherapy, and LDR-BT with chemotherapy. Patients' mandible and maxilla were protected with spacers. Forty-seven patients underwent tooth extraction, and the incidence, site, and relationship of ORN with tooth extraction were recorded. A subgroup of 26 patients received additional EBRT to the neck after dissection for late cervical lymph node metastases. Of 145 patients, six (4.1%) developed ORN on the same side of the mandible as LDR-BT, and EBRT was performed before and/or after LDR-BT on the sites where ORNs developed. Five of 47 (10.6%) patients who underwent tooth extraction after LDR-BT developed ORN. ORN incidence was 1.8% (2/109) in the LDR-BT and/or chemotherapy group and 11.1% (4/36) in the combination LDR-BT and EBRT and/or chemotherapy group for primary tongue cancer. Different irradiation methods (LDR-BT and/or chemotherapy and combination LDR-BT and EBRT and/or chemotherapy) and the presence or absence of tooth extraction showed significant differences (p = 0.0335 and p = 0.0139, respectively) with or without ORN. Mandibular tooth extraction should be avoided on the side of LDR-BT in combined EBRT cases. However, tooth extraction is feasible using a spacer in LDR-BT and/or chemotherapy.

High-Dose Rate Brachytherapy Alone for Treatment of Unfavorable Intermediate Risk Prostate Cancer: A Propensity-Score Matched Analysis.

To demonstrate the feasibility of high-dose rate brachytherapy (HDR BT) as monotherapy for unfavorable intermediate risk (UIR) prostate cancer by comparing survival outcomes of HDR BT alone against external beam radiation therapy (EBRT) + HDR BT boost, +/- androgen deprivation therapy (ADT) using propensity-score matched (PSM) data. This retrospective study queried two data registries collecting patient data from 1991 to present. 633 patients with UIR prostate cancer treated with HDR BT alone, HDR BT+EBRT or HDR+EBRT+ADT were included. HDR BT patients received 42-45Gy/6 fractions (fx) or 27 Gy/2 fx. For HDR BT+EBRT, the HDR dose was 20-24 Gy/2 fx, 24 Gy/4 fx, or 15 Gy/1 fx. EBRT patients received 45 Gy/25 fx to the prostate +/- pelvic nodes. GU/GI toxicities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Time-to-event analyses were carried out to evaluate the relationship between treatments and five primary endpoints of interest: freedom from biochemical recurrence (FFBC), freedom from distant metastasis (FFDM), freedom from local failure (FFLF), cancer specific survival (CSS), and overall survival (OS) at 5 years. PSM was performed with one-to-n matching. Logistic regression was used to estimate the respective propensity scores. The five potential confounders identified were T-stage, Gleason score, pre-treatment PSA, age, and percent positive cores. Balance was checked using the standardized mean difference of covariates. Univariate and multivariate analyses were conducted on the matched data. Toxicity analysis was performed via association between a change in pre- and post-treatment GU/GI toxicity status and the treatment group, as well as incidence of post-treatment severe GI/GU toxicity (grade 3 or higher) and the treatment group. Univariate analysis with Kaplan-Meier method and log rank test comparison between the three cohorts demonstrated no significant difference in all survival outcomes FFBC, FFDM, FFLF, CSS, OS (p = 0.15, 0.19, 0.29, 0.57, 0.28, respectively). Multivariate analysis with Cox proportional hazard regression showed no differences in HR for FFBC and OS (p = 0.95, 0.11) with addition of EBRT, or with EBRT+ADT (p = 0.17, 0.24); no fit was obtainable for FFDM, CSS, FFLF. Toxicities between the three cohorts were not significantly different when comparing post-treatment and baseline GI/GU symptoms (p = 0.53/1). No Grade 2 or 3 GI toxicities were identified, while 8%/1% HDR patients, 10%/1% HDR+EBRT patients, and 12%/2% HDR+EBRT+ADT patients experienced Grade 2/3 GU toxicities. The incidence of grade 3 or higher GU toxicities between the three groups was not significantly different (p = 0.91). This propensity-score matched study demonstrates the feasibility of HDR BT alone for effective treatment of UIR prostate cancer when compared to HDR+EBRT or HDR+EBRT+ADT, while potentially minimizing the added toxicities of EBRT and the undesirable side effect profile of ADT.

The survival impact of adjuvant radiotherapy and chemotherapy in patients with non-endometrioid endometrial carcinomas: a PSM-IPTW analysis based on SEER database

PurposeTo investigate outcomes of adjuvant treatments for non-endometrioid endometrial carcinomas (NEEC), as previous studies are limited by its rarity and heterogeneity.Patients and methodsPatients with endometrial serous carcinoma (SC), clear cell carcinoma (CCC) and carcinosarcoma were identified between 2004 and 2018 from SEER database. Propensity score matching (PSM) along with inverse probability treatment weighting (IPTW) technique were employed to balance confounding factors. Multivariate, exploratory subgroup and sensitivity analyses were conducted to evaluate the impact of adjuvant treatment on overall survival (OS) and cause-specific survival (CSS).ResultsThe cohort comprised 5577 serous, 977 clear cell, and 959 carcinosarcomas. Combined chemotherapy and radiotherapy (CRT), chemotherapy alone, and radiotherapy alone were respectively administered in 42.21%, 47.27% and 10.58% of the whole cohort. Prior to adjusting, chemotherapy plus brachytherapy yielded the most beneficial effect among various strategies. After PSM-IPTW adjustment, CRT still demonstrated beneficial effect on OS and CSS. Subgroup analysis indicated CRT improved survival among various TNM stages, particularly with uterine carcinosarcoma. In the sensitivity analyses for serous histology, brachytherapy with or without chemotherapy appeared to benefit stage I-II patients. In stage III-IV SC patients, chemotherapy plus brachytherapy was still associated with improved survival outcomes. When nodal metastases were identified, additional external beam radiotherapy (EBRT) to CT was more utilized with survival improvement.ConclusionIn NEEC patients, combined CRT yielded beneficial effects than any single mode. Both chemotherapy and brachytherapy promoted survival in early stage SC patients. Late stage SC patients may benefit from chemotherapy plus either EBRT or brachytherapy.

Radiation to all macroscopic sites of tumor permits greater systemic antitumor response to in situ vaccination

BackgroundThe antitumor effects of external beam radiation therapy (EBRT) are mediated, in part, by an immune response. We have reported that a single fraction of 12 Gy EBRT combined with...

Systematic review of intraoperative radiation therapy for head and neck cancer.

Multidisciplinary treatments with surgery, radiation therapy, and chemotherapy are the cornerstones in the management of locally advanced head and neck malignancies. In most cases, radiation is delivered via external beam radiation therapy (EBRT). Intraoperative radiation therapy (IORT), on the other hand, is the delivery of precise doses of radiation to selected target volumes within the exposed surgical field while at the operating room. Most studies on its use on head and neck cancers are limited to single-institutional retrospective case series. We performed a systematic review to consolidate the existing literature on IORT for head and neck malignancies. Fifty-two studies representing a mixed population of 2,389 patients were included in this review. IORT via electrons (intraoperative electron radiation therapy), brachytherapy (intraoperative high dose-rate brachytherapy) or photons was administered in numerous settings, but most commonly as part of a reirradiation regimen following salvage surgery for recurrent tumours. Often, additional EBRT was also planned postoperatively. This review illustrates that IORT is a promising treatment modality in head and neck cancer. Multiple single-institutional studies spanning several decades have demonstrated benefit in terms of local control with reasonable toxicity. However, randomised trials comparing it with current standards of care are still needed.

Immunotherapy with radiotherapy fails to improve prognosis of patients with stage IV non-small cell lung cancer: a retrospective cohort analysis of the THUNDER-2 study

Radiotherapy (RT) may enhance the systemic antitumor reaction to immunotherapy (IT). Currently, the effect of RT in stage IV non-small cell lung cancer (NSCLC) patients treated with IT is uncertain. This study aimed to confirm the role of RT in these patients. We enrolled 120 stage IV NSCLC patients who had been treated with IT and had received external beam radiation therapy (EBRT) or radioactive particle implantation (RPI) at 3 oncology centers in Shandong province between 2019 and 2021. We assessed relevant clinical factors and regular follow-up was conducted via electronic medical records and telephone. The primary endpoint was overall survival (OS). Different combination models in various populations were compared by generating Kaplan-Meier curves and Cox regression analysis. The OS for the overall population was 5 months (range, 0-31 months) and the overall survival rate was 47.5%. Patients receiving IT with RPI had the least favorable prognostic trend (median survival: 2 months) compared to those receiving IT without RT (median survival: 9 months) and IT with EBRT (median survival: 10 months), but this difference was not significant (P=0.148). In subgroup analysis, patients treated with IT with RPI appeared to have a worse prognosis in some specific cohorts, such as males [hazard ratio (HR) =2.433, P=0.031], non-squamous carcinoma histologies (HR =2.680, P=0.034), patients with oligometastases (HR =7.967, P=0.024), patients with liver metastases (HR =10.808, P=0.011) or brain metastases (HR =20.087, P=0.005), and those with Eastern Cooperative Oncology Group (ECOG) performance score ≥2 (HR =2.769, P=0.043). Multivariate Cox analysis of total population revealed that ECOG score and IT stage were the independent prognostic factors. IT combined with EBRT did not have a significant survival benefit in all subgroups. Concurrent IT with RT and first-line and second-line IT combined with RT trended toward improved long-term prognosis. While the robustness of the present conclusions is limited by relatively small sample size and retrospective nature of this research, the addition of EBRT or RPI to IT did not significantly improve patients' OS in stage IV NSCLC. Early combination IT after RT may benefit patients with long-term survival.

Impact of preoperative magnetic resonance imaging on surgery and eligibility for intraoperative radiotherapy in early breast cancer.

We looked at the usefulness of magnetic resonance imaging (MRI) in decision-making and surgical management of patients selected for intraoperative radiotherapy (IORT). We also compared lesion size measurements in different modalities (ultrasound (US), mammogram (MMG), MRI) against pathological size as the gold standard. 63 patients eligible for IORT based on clinical and imaging criteria over a 34-month period were enrolled. All had MMG and US, while 42 had additional preoperative MRI for locoregional preoperative staging. Imaging findings and pathological size concordances were analysed across the three modalities. MRI changed the surgical management of 5 patients (11.9%) whereby breast-conserving surgery (BCS) and IORT was cancelled due to detection of satellite lesion, tumor size exceeding 30mm and detection of axillary nodal metastases. Ten of 42 patients (23.8%) who underwent preoperative MRI were subjected to additional external beam radiotherapy (EBRT); 7 due to lymphovascular invasion (LVI), 2 due to involved margins, and 1 due to axillary lymph node metastatic carcinoma detected in the surgical specimen. Five of 21 (23.8%) patients without prior MRI were subjected to additional EBRT post-surgery; 3 had LVI and 2 had involved margins. The rest underwent BCS and IORT as planned. MRI and MMG show better imaging-pathological size correlation. Significant increase in the mean 'waiting time' were seen in the MRI group (34.1 days) compared to the conventional imaging group (24.4 days). MRI is a useful adjunct to conventional imaging and impacts decision making in IORT. It is also the best imaging modality to determine the actual tumour size.

Geographic Accessibility and Availability of Radiotherapy in Ghana

Radiotherapy is critical for comprehensive cancer care, but there are large gaps in access. Within Ghana, data on radiotherapy availability and on the relationship between distance and access are unknown. To estimate the gaps in radiotherapy machine availability in Ghana and to describe the association between distance and access to care. This is a cross-sectional, population-based study of radiotherapy delivery in Ghana in 2020 and model-based analysis of radiotherapy demand and the radiotherapy utilization rate (RUR) using the Global Task Force on Radiotherapy for Cancer Control investment framework. Receipt of radiotherapy and the number of radiotherapy courses delivered. Geocoded location of patients receiving external beam radiotherapy (EBRT); median Euclidean distance from the district centroids to the nearest radiotherapy centers; proportion of population living within geographic buffer zones of 100, 150, and 200 km; additional capacity required for optimal utilization; and geographic accessibility after strategic location of a radiotherapy facility in an underserviced region. A total of 2883 patients underwent EBRT courses in 2020, with an actual RUR of 11%. Based on an optimal RUR of 48%, 11 524 patients had an indication for radiotherapy, indicating that only 23% of patients received treatment. An investment of 23 additional EBRT machines would be required to meet demand. The median Euclidean distance from the district centroids to the nearest radiotherapy facility was 110.6 km (range, 0.62-513.2 km). The proportion of the total population living within a radius of 100, 150 and 200 km of a radiotherapy facility was 47%, 61% and 70%, respectively. A new radiotherapy facility in the northern regional capital would reduce the median of Euclidean distance by 10% to 99.4 km (range, 0.62-267.7 km) and increase proportion of the total population living within a radius of 100, 150 and 200 km to 53%, 69% and 84%, respectively. The greatest benefit was seen in regions in the northern half of Ghana. In this cross-sectional study of geographic accessibility and availability of radiotherapy, Ghana had major national deficits of radiotherapy capacity, with significant geographic disparities among regions. Well-planned infrastructure scale-up that accounts for the population distribution could improve radiotherapy accessibility.

Advances in External Beam Radiation Therapy and Brachytherapy for Cervical Cancer

The standard of care for the definitive treatment of locoregionally advanced cervical cancer is external beam radiation therapy (EBRT) with concurrent chemotherapy followed by a brachytherapy boost. Historically, EBRT was delivered via a two-dimensional technique based primarily on bony landmarks. This gave way to three-dimensional conformal radiation therapy, which allows for dose calculation and adjustment based on individual tumour and patient anatomy. Further technological advances have established intensity-modulated radiation therapy (IMRT) as a standard treatment modality, given the ability to maintain tumoricidal doses to target volumes while reducing unwanted radiation dose to nearby critical structures, thereby reducing toxicity. Routine image guidance allows for increased confidence in patient alignment prior to treatment, and the ability to visualise the daily position of the targets and organs at risk has been instrumental in allowing safe reductions in treated volumes. Additional EBRT technologies, including proton therapy and stereotactic body radiation therapy, may further improve the therapeutic index. In the realm of brachytherapy, a shift from point-based dose planning to image-guided brachytherapy has been associated with improved local control and reduced toxicity, with additional refinement ongoing. Here we will discuss these advances, the supporting data and future directions.

Radiation necrosis after a combination of external beam radiotherapy and iodine-125 brachytherapy in gliomas

PurposeFrequency and risk profile of radiation necrosis (RN) in patients with glioma undergoing either upfront stereotactic brachytherapy (SBT) and additional salvage external beam radiotherapy (EBRT) after tumor recurrence or vice versa remains unknown.MethodsPatients with glioma treated with low-activity temporary iodine-125 SBT at the University of Munich between 1999 and 2016 who had either additional upfront or salvage EBRT were included. Biologically effective doses (BED) were calculated. RN was diagnosed using stereotactic biopsy and/or metabolic imaging. The rate of RN was estimated with the Kaplan Meier method. Risk factors were obtained from logistic regression models.ResultsEighty-six patients (49 male, 37 female, median age 47 years) were included. 38 patients suffered from low-grade and 48 from high-grade glioma. Median follow-up was 15 months after second treatment. Fifty-eight patients received upfront EBRT (median total dose: 60 Gy), and 28 upfront SBT (median reference dose: 54 Gy, median dose rate: 10.0 cGy/h). Median time interval between treatments was 19 months. RN was diagnosed in 8/75 patients. The 1- and 2-year risk of RN was 5.1% and 11.7%, respectively. Tumor volume and irradiation time of SBT, number of implanted seeds, and salvage EBRT were risk factors for RN. Neither of the BED values nor the time interval between both treatments gained prognostic influence.ConclusionThe combination of upfront EBRT and salvage SBT or vice versa is feasible for glioma patients. The risk of RN is mainly determined by the treatment volume but not by the interval between therapies.

The use of hyperbaric oxygen to treat actinic rectal fistula after SpaceOAR use and radiotherapy for prostate cancer: a case report

BackgroundIn definitive radiation therapy for prostate cancer, the SpaceOAR® System, a hydrogel spacer, is widely used to decrease the irradiated dose and toxicity of rectum. On the other hand, periprostatic abscesses formation and rectal perforation are known as rare adverse effects of SpaceOAR. Nevertheless, there is a lack of reports clarifying the association between aggravation of abscesses and radiation therapy, and hyperbaric oxygen therapy (HBOT) is effective for a peri-SpaceOAR abscess and rectal perforation.Case presentationWe report a case of a 78-year-old high-risk prostate cancer patient. After SpaceOAR insertion into the correct space, he started to receive external beam radiation therapy (EBRT). He developed a fever, perineal pain and frequent urination after the completion of EBRT, and the magnetic resonance imaging (MRI) revealed a peri-SpaceOAR abscess. Scheduled brachytherapy was postponed, administration of antibiotics and opioid via intravenous drip was commenced, and transperineal drainage was performed. After the alleviation of the abscess, additional EBRT instead of brachytherapy was performed with MRI-guided radiation therapy (MRgRT). On the last day of the MRgRT, perineal pain reoccurred, and MRI and colonoscopy detected the rectal perforation. He received an intravenous antibiotics drip and HBOT, and fully recovered from the rectal perforation.ConclusionsOur report indicates that EBRT can lead to a severe rectum complication by causing inflammation for patients with a peri-SpaceOAR abscess. Furthermore, HBOT was effective for the peri-SpaceOAR abscess and rectal perforation associated with EBRT.

Intraoperative Radiation Therapy for Early-Stage Breast Cancer: A Single-Institution Experience

We assessed patient outcomes and toxicity after the use of intraoperative low-energy photon radiotherapy for select early-stage breast cancer (ESBC) patients. This is a retrospective review of patients with unilateral ESBC treated with breast-conservation surgery followed by low-energy photon intraoperative radiotherapy (IORT) at a single institution between 2010 and 2017. Institutional suitability guidelines included: age ≥ 50 years, invasive ductal carcinoma (IDC) with or without DCIS, grade 1 – 2 tumors < 3 cm, ER and or PR positive, Her2 negative, clinically node negative, no lymphovascular space invasion (LVSI), and negative margins (>2 mm). 20 Gy was prescribed to the surface of the spherical applicator fitted to the surgical cavity at surgery. Postoperative patients who did not meet institutional guidelines for IORT alone were recommended adjuvant treatment, including possible additional surgery, external-beam radiotherapy (EBRT), chemotherapy, and/or endocrine therapy. Kaplan-Meier estimates and Cox regression analysis were used to assess ipsilateral breast tumor recurrence (IBTR), overall survival (OS), and relapse-free survival (RFS). 201 patients were included with a median follow up of 5.1 years. Most patients met institutional guidelines for IORT for ESBC. The median age was 67 years; 88% were Her2 negative and ER positive and/or PR positive, 97% had IDC, 87% had grade 1 or 2 disease on biopsy, and 95% had T1 disease. On final pathology, 8% had LVSI, 25% had close (<2 mm) margins, and 3% had positive margins. Most had pathological T1 (93%) N0 (95%) disease. The median IORT applicator size was 4.5 cm with a mean dose at 1 cm depth of 6.3 Gy delivered over an average of 37 minutes. 10% of patients completed additional surgery, 11% additional EBRT, 9% adjuvant chemotherapy, and 74% received adjuvant hormonal therapy. The median total EBRT dose was 42.4 Gy (range 40.05 - 63 Gy) with a median dose of 2.65 Gy/fraction. The 5-year cumulative risk of IBTR was 2%. There was no statistically significant difference in IBTR between patients considered unsuitable by our institutional guidelines (p = 0.93) or by the 2016 ASTRO consensus guidelines (p = 0.26) compared to patients who were considered suitable for IORT alone, by respective guidelines. Of the 98 patients who did not meet institutional criteria based on final surgical pathology, 32% received adjuvant EBRT. Of the 9 patients who experienced IBTR, 5 patients did not undergo indicated EBRT. The 5-year OS rate was 95% with no breast cancer-related deaths. The 5-year RFS rate was 96%. 83% of patients had documented toxicity information and the overall highest reported grade 3 toxicity was 8%; seroma was the most common grade 3 toxicity (4%). IORT for select patients with ESBC has led to acceptable outcomes in regards to ipsilateral breast tumor recurrence and toxicity. We continue to recommend adjuvant EBRT for patients who do not meet IORT suitability criteria upon review of final pathology.

Intraoperative radiation therapy in non-breast cancer patients: A report of 26 cases from Shiraz, south of Iran.

Background: Intraoperative radiation therapy (IORT) is the delivery of radiation at the time of surgery. Whereas the dose delivered by external beam radiation therapy (EBRT) is limited by the tolerance of the surrounding normal tissues, IORT allows exclusion of a part or all of the dose-limiting sensitive structures by operative mobilization and/or direct shielding of these structures. The aim of the present study was to report the non-breast cancer patients' outcomes after receiving IORT in Shiraz, Iran. Methods: In this retrospective study, all cases who had received IORT and had non-breast malignancies were selected. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI) and computed tomography (CT). IORT was applied by self-shielded, LIAC 6-12 MeV Sordina mobile linear accelerator. Typically, a single dose of 10-21 Gy was given for maximally resected tumors. The statistical analyses were carried out using SPSS (version 21). Results: Twenty-six patients were treated with IORT alone or combined with EBRT. Different tumors were treated, including colorectal adenocarcinoma (10 cases, 38.4 %), Soft Tissue Sarcomas (STS, 11 cases, 42.3 %), head and neck cancers (3 cases, 11.5 %), one cervix malignancy case and one paravertebral fibromatosis case. Mean ± SD overall survival was 15±14.89 (0-38) and 34.3±15.72 (14-53) months for colorectal cancer and STS, respectively. Conclusion: IORT is mostly useful for pelvic and abdominal malignancies where normal bowel limits the dose that can be delivered with EBRT. However, the dose delivered in a single fraction with IORT is rarely sufficient for tumor control; therefore, IORT is usually preceded or followed by additional EBRT which should be further evaluated preferably in prospective randomized trials.

Intraoperative radiotherapy in early-stage breast cancer: Multidiciplinary management and analysis of outcome.

e12036 Background: The TARGIT-A trial investigated the efficacy of using single-dose targeted intraoperative radiotherapy (IORT) in place of whole-breast external beam radiotherapy (EBRT) for treating breast cancer. IORT is an effective alternative to EBRT for adjuvant treatment of select patients with estimated conversion rate of 15%, who required additional EBRT following complete pathologic staging. An institutional study was performed to evaluate the rate of patients who received IORT but still required EBRT, in-breast-tumor recurrence rate (IBTR) and overall survival (OS). Methods: Institutional retrospective review of patients treated with IORT was performed, including age at the time of IORT, histology, AJCC stage, margin, and clinical features as outlined in ASTRO and ABS guideline. Conversion rate, IBTR and OS was calculated. Reason for conversion to EBRT assessed. Results: From 1/1/2016 to 1/1/2019, 35 patients underwent IORT concurrent with lumpectomy and sentinel node biopsy within the ASTRO and ABS guideline. Patients median age 60 (51-79 yo) and all had ER+, clinical T(0.5 -2.5cm)N0 with intraoperative sentinel node frozen section evaluation. Zeiss IORT consisted 50 KV x-rays with spherical applicators, and a dose of 20Gy was prescribed at the surface of the applicator. 14.2% (5/35) were recommended EBRT. Conversion was due to microscopic disease found on final surgical pathology (3 node positive and 2 positive surgical margin). 4 patients successfully completed EBRT and 1 patient declined EBRT. 100% underwent adjuvant endocrine treatment. IBTR was 0% and OS was 100% with a median follow-up of 18.6 months (range of 2 – 35 months). Conclusions: Pathologic false negative rate contributed to EBRT conversion rate but remained below 15% TARGIT-A threshold. IORT concurrent with lumpectomy within a risk adapted approach is a good option for eligible patients using evidence-based guideline and multidisciplinary team model. Continued cohort assessment for IBTR, OS and toxicity outcome will be prospectively assessed.

Placement of cesium-131 permanent brachytherapy seeds using the endoscopic endonasal approach for recurrent anaplastic skull base meningioma: case report and technical note.

There are few therapeutic options available for the treatment of recurrent meningiomas that have failed treatment with surgery and external-beam radiation therapy (EBRT). As additional EBRT is clinically risky, brachytherapy offers an important alternative for optimizing local control. In skull base meningiomas, the endoscopic endonasal approach (EEA) has demonstrated an excellent extent of resection. However, in the case of recurrent, atypical, or residual meningiomas, the EEA alone may not be adequate to address microscopic, residual, highly proliferative disease. In this situation, local radioactive seed brachytherapy has been shown to improve control, but few reports of this technique exist. A 48-year-old right-handed man presented on multiple occasions with recurrence of an anaplastic skull base meningioma, after multiple prior gross-total resections and multiple rounds of radiotherapy had failed. The authors performed a maximally safe neurosurgical tumor resection via EEA supplemented by the intraoperative implantation of 131Cs low-dose permanent brachytherapy seeds. They describe a technique for permanent implantation of brachytherapy seeds and provide operative video of this technique. The authors submit that utilizing this technique in combination with EEA tumor resection renders a minimally invasive approach to improving local control in a patient with a recurrent anaplastic or atypical meningioma of the skull base.

Multidisciplinary approach to endobronchial HDR brachytherapy as an alternative to external beam radiation for palliating malignant airway obstruction.

132 Background: Concerns over the safety of high-dose-rate (HDR) endobronchial brachytherapy (EBB) has limited its widespread use in palliating pulmonary airway obstruction. Morbidity following EBB is commonly attributed to fatal hemoptysis and fistula formation. We implemented a procedure to deliver EBB under general anesthesia to minimize procedure risks, while maintaining treatment effectiveness. We hereby report outcomes of consecutive patients treated using this approach to palliate airway obstruction. Methods: We retrospectively reviewed charts of consecutive patients treated with EBB. Treated patients had obstructive lesions &gt;2cm distal to the carina and central structures, who were deemed candidates for EBB by a multidisciplinary team of interventional pulmonologists (IP) and radiation oncologists (RO). All patients were treated under general anesthesia. Bronchoscopy and localization of target lesions was performed by IP. HDR catheters carrying a marker wire were advanced past obstructive lesion. CT simulation was performed to confirm catheter placement, and perform CT-based 3D treatment planning. A dose of 6 -7 Gy/fraction was prescribed at 1 cm from catheter surface. Results: 25 patients (ages 29 -71, mean 52 years) were treated with EPP. 5 had previously received external beam radiation (EBRT) and 3 had concurrent EBRT and EPP. Overall, a total of 76 EBB treatments were performed, with a median of 3 weekly fractions per patient (range 1-6) to total dose of 18Gy. There were no incidences of major bleeding (&gt;50 mL) or fatal hemoptysis in the 30 days following EPP. Moreover, there were no cases of severe (Grade 3 or higher) CTCAE toxicity reported. After a median follow up of 30 months (range 4-42) only 1 out of 17 patients treated with EPP alone required additional EBRT for airway obstruction, 12 months following EPP. Conclusions: Our data suggest the safety and efficacy of an expert multidisciplinary approach to palliating pulmonary airway obstruction using EPP. This approach provides effective palliation of airway obstruction and decreased the need for additional EBRT in majority of treated patients.

Safety and efficacy of posterior sub-Tenon's carboplatin injection versus intravitreal melphalan therapy in the management of retinoblastoma with secondary vitreous seeds.

To evaluate the safety and efficacy of posterior sub-Tenon's carboplatin injection compared to intravitreal melphalan injection in the management of retinoblastoma (RB) with secondary vitreous seeds. The outcome measures were vitreous seeds regression, need for other treatment modalities to achieve ocular salvage and treatment side effects. A prospective interventional comparative nonrandomized study included RB eyes developed secondary vitreous seeds during the period of follow up. They subdivided into two groups: study group I where posterior sub-Tenon's carboplatin (20 mg/2 mL) was injected and study group II where intravitreal melphalan (20 µg /0.1 mL) was injected. The injections repeated every 2-4wk. Thirty-three eyes were included in the study. Seventeen eyes (16 patients) in study group I and 16 eyes (16 patients) in study group II. Ten eyes (30.3%) were completely salvaged following local chemotherapies. Ocular salvage was 23.5% following posterior sub-Tenon's carboplatin injection versus 37.5% following intravitreal melphalan raised to 47.1% and 75% with addition of external beam radiotherapy (EBR) with no statistically significant difference between the study groups (P=0.16). A statistically significant correlation was found between ocular salvage rate and type of vitreous seeds either dust, spheres and clouds (r=0.42, P=0.015) and eyes harbor new solid tumor growth (r=0.35, P=0.045). The mean and median follow up periods following local chemotherapy injections were 2.0y in the study group I and 2.37y in the study group II. Few complications were reported: periorbital edema in all eyes and ocular motility disturbances in 13 eyes (76.5%) following posterior sub-Tenon's carboplatin injection. Vitreous hemorrhage developed in 2 eyes (12.5%) and localized retinopathy in 5 eyes (31.25%) following intravitreal melphalan. Local chemotherapy for treatment of RB with secondary vitreous seeds is safe and can salvage 30.3% of eyes without EBR. There is a superiority of intravitreal melphalan in ocular salvage however, no statistically significant difference between both groups.

Outcomes and toxicities in patients with intermediate-risk prostate cancer treated with brachytherapy alone or brachytherapy and supplemental external beam radiation therapy.

To evaluate the cancer control outcomes and long-term treatment-related morbidity of brachytherapy as well as combination brachytherapy and external beam radiation therapy (EBRT) in patients with intermediate-risk prostate cancer. A retrospective review was conducted in a prospectively collected database of patients with intermediate-risk prostate cancer who were treated either with brachytherapy or brachytherapy and EBRT, with or without androgen deprivation therapy (ADT), in the period 1990-2014. Urinary and erectile dysfunction symptoms were measured using the International Prostate Symptom Score (IPSS), the Mount Sinai erectile function scale and the Sexual Health Inventory for Men (SHIM). Cancer control endpoints included biochemical failure and development of distant metastases. All statistical analyses were carried out using the Statistical Package for Social Science (SPSS). Survival curves were calculated using Kaplan-Meier actuarial methods and compared using log-rank tests. Cox regression multivariate analyses were used to test the effect of multiple variables on treatment outcomes. A total of 902 patients were identified, with a median follow-up of 91 months. Of these, 390 received brachytherapy and 512 received combination therapy with EBRT. In patients with one intermediate-risk factor, the addition of EBRT did not significantly affect freedom from biochemical failure or distant metastases. Among patients with two or three intermediate-risk factors, added EBRT did not improve freedom from biochemical failure. Significant differences in late toxicity between patients treated with brachytherapy vs combination brachytherapy and EBRT were identified including urge incontinence (P < 0.001), haematuria (P < 0.001), dysuria (P < 0.001), and change in quality-of-life IPSS (P = 0.002). These symptoms were reported by patients at any point during treatment follow-up. Analysis of patients who were potent before treatment using actuarial methods showed that patients receiving combination therapy more frequently experienced loss of potency, as measured by the Mount Sinai erectile function scale (P = 0.040). Brachytherapy monotherapy results in equal biochemical and distant control in both patients with one and more than one intermediate-risk features. While no significant benefit was shown, we believe that the addition of EBRT may prevent recurrence in patients with multiple intermediate-risk features and should be considered.

Contribution of intraoperative radiotherapy (IORT) for therapeutic de-escalation in early breast cancer: Report of a single institution's experience.

The spread of systematic screening and the emergence of oncoplastic techniques allow more breast conservative treatment associating lumpectomy and external beam radiation therapy. In order to furthermore facilitate the patient's treatment, intraoperative radiation therapy (IORT) has been developed. The oncological safety of this technique has been studied, and is considered acceptable. Many questions remain unsolved in regard of the toxicity of this procedure as well as the patient's selection criteria. In this study, we present the first results and complications rate of patients treated by IORT in a single French institution. Between 2012 and 2015, all patients with breast cancer treated in a one-step procedure associating lumpectomy and IORT were retrospectively included in a monocentric cohort. Acute and long-term toxicities were evaluated using CTCAE v4.0 classification. 280 breast cancers were treated using IORT procedure. Additional external beam radiation therapy was requested for 45.7% patients. The acute complications rate was 14.6%, with 5 surgical revisions needed (1.78%). With a median follow up of 911 days, the long-term grade-3 toxicity rate was 1.1%. The only risk factor for local fibrosis was external beam radiation therapy (EBRT) (OR = 1.99; IC95 [1.05-3.81], P = 0.036). Three patients (1.07%) were diagnosed with local recurrence. The results from this cohort confirm the low complication and recurrence rate of IORT procedure. A good selection of patients is necessary in order to lower the EBRT rate and allow therapeutic de-escalation. The classification of tumors into IHC subsets seems a good selection gate. Intraoperative radiation therapy appears to have a low toxicity rate with an acceptable local recurrence risk, and should therefore be considered as an option in the treatment of early breast cancer.

Brachytherapy of Intracranial Gliomas.

Interstitial implantation of radioactive materials (brachytherapy [BT]) has been designed to protractedly deliver a high radiation dose to a well-defined target volume, while minimizing irradiation of the adjacent normal tissues. Even though promising results have been reported over time, the role of this treatment modality in the management of brain tumors is still poorly defined, and only a few centers worldwide apply it in clinical practice. Nevertheless, temporary or permanent interstitial implantation of low activity (<20 mCi) and low dose rate (≤10 cGy/h) iodine-125 (125I) seeds as possible therapy of intracranial gliomas is currently undergoing a definite revival, and several indications for its use have been identified. Generally, 125I-BT may be considered a reasonable option in cases of unresectable, well-circumscribed, either newly diagnosed or recurrent tumors with a diameter of ≤4 cm, virtually in any location within the brain. Importantly, this treatment does not narrow down the spectrum of the possible subsequent salvage therapeutic options, since neither repeated interstitial nor additional external beam irradiation at the time of tumor progression after BT is associated with a significantly increased risk of radiogenic complications. Using correct patient selection criteria, appropriate surgical technique, and established treatment parameters, would make BT a truly minimally invasive procedure with a low risk of complications and reasonable efficacy.