Salvage I-125 brachytherapy for locally-recurrent prostate cancer after radiotherapy

PurposeRetrospective, single-institution analysis of clinical outcomes and treatment-related toxicity in patients treated with salvage I-125 low-dose rate (LDR) brachytherapy (BT) for locally-recurrent prostate cancer after radiotherapy.Materials and methodsBetween 2008 and 2018, 30 patients with biopsy-confirmed prostate cancer recurrence underwent salvage treatment with I-125 LDR-BT. Of these 30 patients, 14 were previously treated with primary external beam radiotherapy (EBRT; median dose, 73 Gy) and 16 with primary I-125 LDR-BT (145 Gy and 160 Gy in 14 and 2 cases, respectively). At seed implantation, the mean age was 75.8 years, with a median Gleason score of 7 and pre-salvage PSA of <10 ng/mL. Six patients received androgen deprivation therapy for six months after relapse diagnosis. The prescribed salvage I-125 BT dose to the gland was 120−130 Gy, with dose restrictions of Dmax <135% (urethra) and <100% (rectum). Toxicity was evaluated according to the CTCAE scale (v4.0).ResultsAt a median follow-up of 45 months, the biochemical recurrence-free survival rates at 1, 3 and 5 years were 86.7%, 56.7% and 53.3%, respectively. Overall survival at 5 years was 87%. On the multivariate analysis, two variables were significant predictors of recurrence: PSA at relapse and nadir PSA post-salvage. Grade 3 genitourinary toxicity was observed in 5 patients (radiation-induced cystitis in 3 cases and urethral stenosis in 2) and G3 gastrointestinal toxicity in 3 patients (rectal bleeding).ConclusionSalvage therapy with I-125 brachytherapy is a safe and effective treatment option for locally-recurrent prostate cancer in previously-irradiated patients. High pre-salvage PSA and post-salvage nadir PSA values were significantly associated with a worse disease control after salvage I-125 LDR-BT. In well-selected patients, I-125 LDR-BT is comparable to other salvage therapies in terms of disease control and toxicity. However, more research is needed to determine the optimal management of locally-recurrent prostate cancer.     

Soft-tissue sarcomas of the upper extremity: surgical treatment and outcome

The objective of this retrospective follow-up study was to evaluate the outcome of patients with soft-tissue sarcoma treated by the authors' protocol, which consists of a selective combination of conservative surgery and radiotherapy. Patients who relapsed were especially evaluated to improve treatment results. The authors examined 80 patients with local soft-tissue sarcoma in the upper extremity referred to their multidisciplinary group. Fifteen patients were referred for first or subsequent local recurrence, and 65 patients were treated for primary tumor. The goal of treatment was local control and preservation of a functional limb. Wide excision was attempted. If the margin was less than 2.5 cm, postoperative radiotherapy was administered. Eighty-five percent of the patients were treated by limb salvage. Thirty patients needed reconstructive procedures such as pedicled (20 patients) or free flaps (10 patients). No free flaps were lost. The 5-year disease-specific overall survival rate was 75 percent, the local recurrence-free survival rate was 79 percent, and the metastasis-free survival rate was 68 percent. In univariate analysis, prognostic factors for local recurrence were extracompartmental site; for development of metastases, large size and extracompartmental site; and for decreased disease-specific overall survival, large size and extracompartmental site. Intramuscular, cutaneous, and subcutaneous tumors had a 5-year local control rate of 100 percent, and extracompartmental tumors had a local control rate of 69 percent. Extracompartmental tumors clearly have the worst prognosis and should be the main target for improving treatment strategies. After exclusion of patients with inadequate treatment according to the authors' protocol, the local control rate at 5 years was 90 percent. Strict adherence to treatment protocol should be practiced.     

Local failure after primary radiotherapy in lung cancer: Is there a role for SBRT?

AimOur purpose is to construe the role of stereotactic body radiation therapy (SBRT) in the management of lung cancer from our early experience with SBRT for salvage treatment in patients with recurrent lung cancer after initial radiation therapy.BackgroundLocoregional recurrences are a frequent challenge in patients treated with radio-chemotherapy for locally advanced NSCLC. Conventional external beam radiation therapy (EBRT) is rarely given as salvage treatment because of the risk of toxicity. There is a paucity of published studies evaluating the role of SBRT in this clinical setting.Materials and methodsBetween 2008 and present, 10 patients with biopsy proven non-small cell lung cancer (NSCLC) underwent 14 radiosurgical procedures for salvage therapy after failing initial radiation treatment. Patients’ age ranged from 54 to 88 years with a median of 74 years in 6 males and 4 females. Intervals from initial radiation treatment to salvage SBRT were 3–33 months with a median of 13 months. SBRT treatments were delivered using Intensity Modulated Volumetric Arc Therapy (VMAT). All patients received concomitant chemotherapy.ResultsOverall survival after salvage radiosurgery ranged from 6 to 41 months (mean 20 months, median 18 months). Four of the ten patients are alive with disease locally controlled. Of the remaining 6 patients, 4 had distant progression of disease with brain metastases and one had both brain and lung metastases. The other patient had a regional failure. Toxicities were found in three of the ten (30%) patients with grade I pneumonitis.ConclusionIn our early experience, salvage SBRT is an effective modality of treating patients who failed after conventional irradiation, achieving excellent results in terms of local control with acceptable toxicity. Further prospective studies are needed to determine optimal fractionation schemes.     

Giant locally advanced and metastatic squamous cell skin carcinoma of head and neck region: case report

IntroductionAt the present time, the skin tumors are among the most common cancers. Optimal therapy is based on the extent of the disease and the age of the patient. The need for radiotherapy occurs for inoperable locally advanced tumors and in the event of failure, salvage surgery is applied.Materials and methodsWe provided a case report of an older patient with giant squamous cell skin carcinoma and a review of published articles.ResultsWe present a rare case of giant squamous cell skin carcinoma with metastatic satellite tumors that was primarily treated with curative radiotherapy. Five months after radiotherapy, a recurrent tumor was detected at the site of origin and the treatment was completed by salvage surgery. Full remission was achieved for four years.ConclusionDespite the seemingly incurable finding it is always necessary to consider radical treatment regardless of the patient´s age. Curative treatment could achieve long term remission in the group of older patients.     

The efficiency of the radiobiological and clinical of the intraoperative radiation therapy in combination with distant gamma-radiation therapy of malignant tumors

The efficiency of the radiobiological and the clinical planning of the combination of the intraoperative radiation therapy (IORT) and the external beam radiation therapy (EBRT) was assessed according to the incidence of local recurrences and to the level of radiation-induced damages during 5 years for patients with malignant tumors of head and neck, lung and soft tissues. Criteria of radiobiological planning for performing IORT + EBRT using the modified model of TDF (time-dose-fractionation) for calculating a single IORT dose and total radiation doses was defined among 169 patients of the studied group. The control group included 115 patients who were treated with surgery followed by photon radiation therapy at the total dose of 40-45 Gy. The Clinical critetia for performing the combined treatment with IORT and EBRT were such like: locally-advanced tumors, multicentrical location of tumor sites and the necessity of the increasing of the total doses of the combination of IORT and EBRT. The Average rates of total doses of IORT and EBRT were 67 +/- 2.1 Gy for patients with cancer of nasal cavity and of accessory nasal sinus, 50 +/- 1.8 Gy for patients with oral cavity cancer, 60 +/- 0.7 Gy for patients with lung cancer and 75 +/- 2.0 Gy for patients with sarcomas of soft tissues. Radiation-induced damages for normal tissues such as mandible osteomyelitis, neuritis and pathological bone fracture occurred among 16.8% of patients from the studied group if the TDF factor was exceeded over 100 conventional units. The combined treatment with IORT and EBRT resulted the significant reduction of recurrence rate among 5-year as compared with the combined treatment fot the control group: 37.5 +/- 5.3% and 65 +/- 5.1% of patients with cancer of nasal cavity and accessory nasal sinus; 55.8 +/- 6.3% and 80 +/- 5.9% of patients with oral cavity cancer; 57.8 +/- 6.7% and 75 +/- 5.8% of patients with non-small cell lung cancer and 32.7 +/- 6.1% and 72 +/- 6.7% of patients with sarcomas of soft tissues, respectively. The use of criteria for radiobiological and clinical planning of the combined treatment with IORT and EBRT promotes the improvement of long-term treatment results.     

Stereotactic radiation therapy for skull base recurrences: Is a salvage approach still possible?

AimA literature review was performed to analyse the role of stereotactic radiotherapy given in a single shot or in a fractionated fashion for recurrent skull base tumours in order to ascertain if it can be a real salvage approach.BackgroundThe management of recurrent skull base tumours can have a curative or palliative intent and mainly includes surgery and RT.Materials and methodsOne-thousand-ninety-one articles were found in the search databases and the most relevant of them were analysed and briefly described.ResultsData on recurrences of meningioma, pituitary adenoma, craniopharyngioma, chordoma and chondrosarcoma, vestibular schwannoma, glomus jugulare tumours, olfactory neuroblastoma and recurrences from head and neck tumours invading the base of skull are reported highlighting the most relevant results in terms of local control, survival, side effects and complications.ConclusionsIn conclusion, it emerges that SRS and FSRT are effective and safe radiation modalities of realize real salvage treatment for recurrent skull base tumours.     

Helical tomotherapy re-irradiation for patients affected by local radiorecurrent prostate cancer

BackgroundSalvage re-irradiation in patients affected by radiorecurrent prostate cancer might be a valid as well as challenging treatment option. The aim of this study was to evaluate feasibility and toxicity of salvage external beam radiotherapy (EBRT) re-treatment in patients affected by radiorecurrent prostate cancer within the prostate gland or the prostate bed.Materials and Methods15 patients underwent EBRT re-treatment using helical tomotherapy (HT), with daily Megavolt computed tomography image-guidance. We registered toxicity according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Biochemical relapse was defined as a PSA increase > 20% compared with the pre-EBRT re-treatment value. Survival curves were calculated using the Kaplan-Meier method.ResultsAll patients received a total dose of 50 Gy (25 × 2 Gy), and 7 (46.6%) had concomitant androgen deprivation therapy (median duration of 12 months). With a median follow-up of 40.9 months, the 2-year and 4-year biochemical relapse-free survival were 55% and 35%, respectively. Acute and late genito-urinary (GU) toxicity ≥2 were recorded in 4 (26.6%) and 5 (33.3%) patients, respectively, and the 4-year late GU toxicity was 30%. Acute gastrointestinal toxicity ≥2 was recorded in 2 (13.3%) cases, whereas no patient experienced late toxicity.ConclusionsDespite the inherent bias of a retrospective analysis, our long-term results showed a low toxicity profile with a relatively low rate of biochemical control for HT re-treatment in patients affected by local radiorecurrent prostate cancer. Prospective trials are needed to investigate the role of EBRT in this setting.     

Adjuvant gamma knife surgery and image-guided,intensity-modulated radiation therapy for the treatment of sacral chordomas

AimThe aim of this study was to confirm whether patients with sacral chordoma benefit from adjuvant radiotherapy and to determine the optimal photon radiotherapy module for comprehensive treatment.BackgroundChordoma is a rare slow-growing neoplasm arisen from cellular remnants of the notochord. About 50% occur in the sacrococcygeal region. Surgical resection and adjuvant radiation therapy are recommended treatment due to the improving local control rate.Materials and methods118 patients treated by surgery and adjuvant radiotherapy from August 2003 to May 2015 were retrospectively analyzed. All patients received surgical resection after diagnosis. Among these patients, 44 were treated by exclusive surgery, and 48 were treated with adjuvant image-guided, intensity-modulated radiation therapy (IG-IMRT). In addition, 26 patients were treated with gamma knife surgery (GKS) after surgical resection. The median follow-up was 54 months for all patients. Kaplan–Meier analysis was used to calculate recurrence-free survival (RFS) overall survival (OS).ResultsPatients treated with adjuvant radiotherapy had better RFS (p = 0.014) than those treated exclusively by surgery. The patients in the IG-IMRT group exhibited better recurrence-free survival (p = 0.01) than the GKS group. Moreover, in the IG-IMRT group, patients treated by higher dose were associated with better RFS (p = 0.04). No significant difference in OS was found. No grade 3 late toxicity was found.ConclusionsWe confirmed that adjuvant radiotherapy improved RFS but not OS in sacral chordoma patients after surgery. Furthermore, favorable RFS and low adverse event rates were observed following IG-IMRT. Our results suggest that high dose IG-IMRT is an appropriate module of adjuvant radiotherapy for sacral chordoma patients.     

Anaplastic thyroid cancer: outcomes of trimodal therapy

BackroundThe purpose of this study is to assess the impact of trimodal therapy [surgery, chemotherapy and external beam radiotherapy (EBRT)] in patients with anaplastic thyroid cancer (ATC) treated with curative intent.Materials and methodsRetrospective review of patients with ATC treated at a tertiary referral centre between January 2009 and June 2020. Data were collected regarding demographics, histology, staging, treatment and outcomes.ResultsSeven patients (4 female) were identified. Median age was 58 years (range 52–83 years). All patients received EBRT with concurrent doxorubicin. Six patients received surgery followed by chemoradiotherapy (CRT), and one underwent neoadjuvant CRT followed by surgery. Median radiological tumour size was 50mm (range 40–90 mm). Six patients had gross extrathyroidal extension and three had N1b disease. Prescribed radiotherapy schedules were 46.4 Gy in 29 bidaily fractions (n = 2, treated 2010), 60 Gy in 30 daily fractions (n = 2), 66 Gy in 30 fractions (n = 2) and 70 Gy in 35 fractions (n = 1; patient received neoadjuvant CRT). CRT was discontinued early for two patients due to toxicities. At median follow up of 5.8 months, 42.9% (3/7) patients were alive and disease-free. Only one patient developed a local failure. Three patients died from distant metastases without locoregional recurrence.ConclusionsDespite poor prognosis of ATC, selected patients with operable tumours may achieve high locoregional control rates with trimodal therapy, with possibility of long-term survival in select cases.     

Retroperitoneal primitive neuroectodermal tumour (PNET). A case report and review of the literature

PurposeWe report a clinical case and present a brief review of the literature of peripheral primitive neuroectodermal tumour (PNET) as a rare disease. We discuss the difficult clinical and pathological diagnosis and the multidisciplinary approach to treatment of PNET. We debate radiosensitivity of extracranial recurrent retroperitoneal PNET.Methods and materialsExternal beam radiation therapy was applied for a non-resectable local recurrence of retroperitoneal PNET in a 74-year-old woman. There were no distant metastases and our patient has refused chemotherapy.ResultsLocal tumour control (LTC) was achieved after administration of a total dose of 60 Gy in 30 fractions by external beam 60 Cobalt radiotherapy.ConclusionsPNET is an aggressive malignant tumour infiltrating lymphatics and metastasizing haematogenously. It requires a multimodality treatment. Late local recurrence of extracranial retroperitoneal PNET has shown high radiosensitivity, so local tumour irradiation could be a radical treatment even in non-resectable cases.     

妇科肿瘤患者术后盆腔感染情况调查、 病原菌分布及其危险因素分析

目的调查妇科肿瘤患者术后盆腔感染的情况以及病原菌分布,并探讨术后发生盆腔感染的危险因素。方法回顾性分析自2013年1月到2017年1月在东南大学附属中大医院接受妇科肿瘤手术治疗的384例患者的临床资料。统计妇科肿瘤术后盆腔感染的发生率及病原菌的分布情况。将发生盆腔感染的患者分为感染组,未发生盆腔感染的患者分为未感染组,对比两组的临床资料,并通过多因素Logistic回归分析,归纳妇科肿瘤患者术后发生盆腔感染的危险因素。结果术后发生盆腔感染41例,感染率为10.68%,培养出病原菌54株,其中革兰阳性菌14株,占25.93%,革兰阴性菌35株,占64.81%,真菌5株,占9.26%。感染组患者年龄60岁的比例、手术持续时间2h的比例、合并慢性基础疾病的比例、开放手术的比例、术前化疗的比例、术后留置引流管的比例和术后卧床时间7d的比例均显著高于未感染组(均P0.05);多因素Logistic回归分析结果显示,年龄大、手术持续时间长、合并慢性基础疾病、开放手术、术前化疗、术后留置引流管、术后卧床时间长均是妇科肿瘤患者术后盆腔感染的危险因素(均P0.05)。结论妇科肿瘤患者术后较容易并发盆腔感染,病原菌主要为革兰阴性菌。多种因素可增加术后盆腔感染的风险,临床应加强防控措施,降低妇科肿瘤患者术后盆腔感染的发生率。     

Radiation-induced breast angiosarcoma: report of two patients after accelerated partial breast irradiation (APBI) and review of the literature

BackgroundAngiosarcoma may rarely complicate radiotherapy of breast cancer. This so-called radiation-induced angiosarcoma (RIAS) occurs in less than 0.3% of patients that underwent breast conservation surgeries, usually years after completion of radiotherapy.Case presentationwe introduce two cases of invasive ductal carcinoma who underwent lumpectomy and accelerated partial breast irradiation (APBI) as an alternative protocol to whole breast irradiation (WBI). They received adjuvant partial breast radiotherapy on tumor cavity for a total dose of 38.5 Gy in 10 fractions in 5 days using 3D-external-beam RT. In both cases, RIAS occurred eight years after radiotherapy, in the sub-cicatricial area in one patient and outside the irradiated area in the other one. They both underwent radical surgery and chemotherapy was performed in one patient.DiscussionThe underlying mechanism for development of RIAS is not well known, but its incidence seems to be increasing. RIAS after partial breast irradiation is very rare and has been reported in two cases so far. As it may be suggested in case 2, it is still a matter of debate if the risk of radiation-induced sarcoma is radiation-dose dependent. Although mastectomy is considered as a standard treatment, choice of treatment should be made according to the patient’s specifications.ConclusionThere are very few studies in the literature that report RIAS after APBI. Present study is the only one reporting two cases after the external 3D technique APBI. Prognosis of RIAS remains poor. Only a careful evaluation in a multidisciplinary context can offer to the patients the best result in terms of local control and survival.     

Ultrasound-guided intraoperative electron beam radiation therapy: A phantom study

PurposeTo develop the method for ultrasound (US)-guided intra-operative electron beam radiation therapy (IOERT).MethodsWe first established the simulation, planning, and delivery methods for US-guided IOERT and constructed appropriate hardware (the multi-function applicator, accessories, and US phantom). We tested our US-guided IOERT method using this hardware and the Monte Carlo simulation IOERT treatment planning system (TPS). The IOERT TPS used a compensator to build the conformal dose distribution. Then, we used the TPS to evaluate the effect of setup uncertainty on target coverage by introducing phantom setup error ranging from 0 mm to 10 mm to the plans with and without the compensator.ResultsThe simulation, planning, and delivery methods for US-guided IOERT were introduced and validated on a phantom. A complete technique for US-guided IOERT was established. Target coverage decreased by about 12% and 29% as the phantom setup error increased to 5 mm and 10 mm for the plans with compensator, respectively. Without compensator, the corresponding target coverage decreases were 2% and 13%, respectively.ConclusionIn our study, we developed the multi-function applicator, US Phantom, and TPS for IOERT. The procedures included not only dose distribution planning, but also intraoperative US imaging, which provided the information necessary during surgery to improve IOERT quality assurance. Target coverage was more sensitive to setup errors with compensator compared to no compensator. Further studies are needed to validate the clinical efficacy of this US-guided IOERT method.     

Target volume definition for staple line recurrences of non-small cell lung cancer

BackgroundStaple line (SL) recurrences of non-small cell lung cancer (NSCLC) are commonly treated with radiotherapy (RT), but the target volume definition — whole SL versus focused on recurrence — is unclear. The aim of the study was to determine the appropriate target volume for RT of SL recurrences.Materials and methodsTwenty-two consecutive patients (20 stage I, 2 stage II) treated with salvage RT for SL recurrences were retrospectively analyzed. Imaging features at the time of SL recurrence were evaluated to guide target volume definition.ResultsSurgeryAll patients had complete tumor resection (wedge resection in 10 (45%) and lobectomy in 12 (55%) patients). 14 (64%) patients had risk factors for recurrence, including surgical margins ≤ 2 cm, angiolymphatic and visceral pleural invasion.Salvage RTAfter a median 26 months (9–67), all 22 patients developed SL recurrence which was metabolically active on PET in all and biopsy-confirmed in 18/22 (82%) patients. All patients underwent RT targeting the location of the SL recurrence only. 13/22 (59%) patients had additional PE T-negative nodular or linear SL changes that were not included in the irradiated volume.Recurrence after RTAfter a median 17 months (9–34) 10/22 (45%) patients recurred either regionally 6/10 (60%), in the lungs 4/10 (40%) or distally 3/10 (30%). No patient recurred at the SL. Two-year overall and disease-free survival rates after RT were 71% and 65%, respectively.ConclusionRT to SL recurrences alone results in excellent local control. Additional treatment to reduce regional and distant recurrences should be considered.     

Recurrence patterns of pancreatic cancer treated with adjuvant intensity modulated radiotherapy

BackgroundThe aim of this study was to investigate the recurrence patterns in pancreatic cancer patients treated with adjuvant intensity modulated radiotherapy (IMRT) and to correlate the sites of locoregional recurrence with radiotherapy target volumes.Materials and methodsThirty-eight patients who had undergone resection and adjuvant chemoradiation for pancreatic cancer were evaluated. Radiotherapy (RT) was started after 1–3 cycles of adjuvant chemotherapy (CHT). Clinical target volume (CTV) was contoured according to the RTOG guideline. All patients were treated with IMRT with a dose of 45–50.4 Gy. Computerized tomography (CT) images at the time of recurrence were correlated with radiotherapy plans. Locoregional recurrences were classified as in-field, out-field and marginal.ResultsMedian overall survival (OS) was 19 months. One- and 2-year OS rates were 73.6% and 37.1%, respectively. Locoregional recurrence and distant metastases were observed in 11 (28.9%) and 23 (60.5%) patients, respectively. For the 11 locoregional recurrences, 7 were in-field, 1 was marginal, and 3 were out-of-field. One patient had isolated local, 2 patients had isolated regional and 15 (57.6%) patients had only distant failures. The first presentations of failures were mostly distant (58%). On multivariate analysis, tumor size ≥ 3 cm (p = 0.011) and positive vascular invasion (p = 0.014) predicted for worse OS rate.ConclusionsThe majority of locoregional recurrences were in the radiation field among pancreatic cancer patients treated with postoperative IMRT. However, failures were predominantly distant, and improvement of systemic control may be of particular interest.     

Electron radiotherapy (IOERT) for applications outside of the breast: Dosimetry and influence of tissue inhomogeneities

PurposeThe purpose of study is to investigate the dosimetry of electron intraoperative radiotherapy (IOERT) of the Intraop Mobetron 2000 mobile LINAC in treatments outside of the breast. After commissioning and external validation of dosimetry, we report in vivo results of measurements for treatments outside the breast in a large patient cohort, and investigate if the presence of inhomogeneities can affect in vivo measurements.Methods and materialsApplicator factors and profile curves were measured with a stereotactic diode. The applicators factors of the 6 cm flat and beveled applicators were also confirmed with radiochromic films, parallel-plate ion chamber and by an external audit performed with ThermoLuminescent Dosimeters (TLDs). The influence of bone on dose was investigated by using radiochromic films attached to an insert equivalent to cortical bone, immersed in the water phantom. In vivo dosimetry was performed on 126 patients treated with IOERT using metal oxide-silicon semiconductor field effect transistors (MOSFETs) placed on the tumor bed.ResultsRelatively small differences were found among different detectors for measurements of applicator factors. In the external audit, the agreement with the TLD was mostly within ±0.2%. The largest increase of dose due to the presence of cortical bone insert was +6.0% with energy 12 MeV and 3 cm applicator. On average, in vivo dose was significantly (+3.1%) larger than prescribed dose.ConclusionIOERT in applications outside the breast results in low discrepancies between in vivo and prescribed doses, which can be also explained with the presence of tissue inhomogeneity.     

Dosimetric evaluation of Gafchromic EBT2 film for breast intraoperative electron radiotherapy verification

PurposeQuality assurance (QA) is one of the most important issues that should be addressed for intraoperative electron radiotherapy (IOERT), which is not benefiting from image-based treatment planning system. The aim of this study is to evaluate the dosimetric characteristics of Gafchromic EBT2 film for breast IOERT QA procedure.MethodsDue to the fact that some dedicated accelerators are being used for IOERT, dependence of the film response to energy, field size, dose rate and incidence angle of electron beam from the LIAC IOERT accelerator was studied. Then, film response curve to breast IOERT doses was obtained and its accuracy was evaluated and justified through comparison to the results of ionometric dosimetry.ResultsThe results of this study indicated that there are no significant differences between the film responses at different energies of 6, 8, 10 and 12 MeV (P-value = 0.99). Similarly, no field size dependency was found when evaluating the response of the film to different field sizes ranging from 4 to 10 cm (P-value = 0.94). Film response was found to be independent of the dose rate of intraoperative electron beam (P-value = 0.12). Film response variations with changing the beam incidence angle were not significant (P-value > 0.8). Calibration curve at the dose range of 8–24 Gy had an acceptable accuracy. The difference between the results of film dosimetry and ionometric dosimetry was around 5% which was in agreement with the results of dose uncertainty estimation.ConclusionThe EBT2 film was found to be a potentially appropriate tool for breast IOERT verification.     

Hypofractionated radiotherapy in breast cancer: a 10-year single institution experience

BackgroundModerately post-operative hypofractionated radiotherapy (HYPO-RT) for breast cancer is a safe and effective strategy as seen in large prospective trials. This study aimed to assess overall and disease-free survivals, local control, and acute and late toxicities in patients treated with HYPO-RT.Materials and methodsData from patients submitted to post-operative HYPO-RT, with or without boost, were evaluated retrospectively. Demographic, disease, and treatment characteristics were collected.ResultsFrom March 2009 to December 2016, 393 patients were treated. Breast-conserving surgery was performed in 94.7%, immediate reconstruction after mastectomy in 6 (1.5%). Most patients (91.2%) had initial stage (0 to IIA), and chemotherapy was performed in 42.0%, HYPO-RT was mainly performed in 15 or 16 daily fractions of 267 cGy and 265 cGy, respectively. The median follow-up was 5.7 years. There were 25 deaths (6.4%) and 17 (4.3%) local recurrences. At 5 and 10 years, the overall survival, local control, and disease-free survival were, respectively, 96.0% and 79.3%, 99.2% and 94.9%, 96.6%, and 91.9%. Acute grade 3 or 4 dermatitis was observed in 0.9%. Late grade 1 or 2 occurred in less than 3% of the patients.ConclusionHYPO-RT is a safe and effective radiotherapy regimen with excellent disease control and overall survival rates, with low acute and late toxicity rates.     

Assessment of clinically relevant dose distributions in pelvic IOERT using Gafchromic EBT3 films

PurposeIn IOERT a single dose of radiation is delivered to the tumour site during surgery. Manual dose calculations are used and the irradiation target volume, electron energy and applicator are decided on site by the radiation oncologist. This work assesses the effect that irregular and curved surfaces, typical of pelvic IOERT, may have on the expected dose distribution.MethodsThe feasibility of using Gafchromic EBT3 films and a slab phantom to obtain 2D dose distributions was investigated. Different set-ups were tested by comparison with water tank measurements, applying the gamma function analysis with 2% and 2 mm criteria. The validated set-up was then used to obtain reference dose distributions, which were converted to colour-coded graphical representations. Phantoms with step-like and curved surfaces were created to simulate typical pelvic IOERT irradiation surfaces, and the dose distributions were obtained and compared with the reference distributions.ResultsGood agreement with water tank measurements was obtained for all applicators below 2 mm, using the chosen setup in reference conditions. In non-reference conditions, the presence of a step-like surface creates an adjacent hotspot, followed by a quick reduction of the dose in depth. With curved surfaces, the dose distribution is shifted forward, becoming curved and deeper, but when the applicator is larger than the hole, hotspots are also observed.ConclusionsThe shape of the irradiation surfaces alters the dose distribution. Visualization of these effects is important to assess target coverage and interpret in vivo measurements in pelvic IOERT.