External Beam Radiation Treatment Research Articles

Long-term results of multimodal peptide receptor radionuclide therapy and fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma

BackgroundThe combination of somatostatin receptor-directed peptide receptor radionuclide therapy (PRRT) in combination with external beam radiotherapy (EBRT) might prove a feasible treatment option in patients with advanced meningioma. Patients and methodsFrom May 2010 to May 2011, 10 patients with unresectable meningioma (6 × WHO grade I, 2 × WHO grade II, 2 × WHO grading not available) were treated with one cycle of PRRT followed by EBRT. Long-term toxicity and efficacy were assessed according to Common Terminology Criteria for Adverse Events version 5.0 and magnetic resonance imaging-based Response Assessment in Neuro-Oncology Working Group criteria, respectively. ResultsDuring long-term follow-up of a median of 105.0 months (range, 38.2–111.4 m), combined PRRT and EBRT was well-tolerated with no severe acute or chronic toxicity. Kidney or bone marrow function was not affected in any patient. Combination of PRRT and EBRT resulted in disease stabilization in 7 of the 10 patients with a median progression-free survival of 107.7 months (range, 47.2–111.4 m) vs. 26.2 months (range, 13.8–75.9 m) for the patients with meningioma progression. ConclusionsThe combination of PRRT and EBRT is a feasible and safe therapeutic option in meningioma patients. In this pilot cohort, the multimodality treatment demonstrated good disease stabilization.

Craniofacial second primary tumors in patients with germline retinoblastoma previously treated with external beam radiotherapy: A retrospective institutional analysis.

The long-term survival of germline retinoblastoma patients is decreased due to the risk of second primary tumors (SPTs) that occur years after the diagnosis of retinoblastoma. This risk is related to genetic predisposition and other factors, such as the treatment of retinoblastoma by external beam radiotherapy (EBRT). We studied the incidence, risk factors, and prognosis of specific craniofacial SPTs developed within the margins of radiation field in a cohort of 209 patients with germline retinoblastoma treated with EBRT at our institution between 1977 and 2010. Clinical characteristics, survival, incidence, and histology of craniofacial SPTs were recorded. Fifty-three of the 209 patients developed 60 distinct craniofacial SPTs in irradiated field with a median time from EBRT of 16.9 years (4-35) and a median follow-up of 24.8 years (5.3-40). Osteosarcoma (33.3%) and undifferentiated sarcoma (23.3%) were the more prevalent histological entities. Benign tumors (16.7%) also occurred. The cumulative incidence of craniofacial SPTs reached 32.6% at 35 years after EBRT, and the median survival after diagnosis was five years. In our series, irradiation under 12 months of age, bilateral EBRT, or previous treatment of retinoblastoma with chemotherapy did not significantly increase the risk of craniofacial SPTs. This work presents a strong argument to avoid EBRT in the management of retinoblastoma and emphasizes the high risk and poor prognosis of specific craniofacial SPTs. This study also points to the question of the need and benefits of special programs for early detection of craniofacial SPTs in survivors of irradiated germline retinoblastoma.

The effectiveness and prognostic factors of radioactive iodine-125 seed implantation for the treatment of cervical lymph node recurrence of esophageal squamous cell carcinoma after external beam radiation therapy.

PurposeTo analyze factors influencing the efficacy of 125I seed implantation in the treatment of in-field cervical lymph node recurrence of esophageal squamous cell carcinoma (ESCC) after external beam radiation therapy.Material and methodsWe conducted a retrospective review of 36 patients with in-field cervical metastatic lymph nodes recurrence of esophageal squamous cell carcinoma (CML-ESCC) after external beam radiation therapy treatment, who underwent 125I seed implantation in our department from 2013 to 2019. Previous cumulative external irradiation dose ranged from 20 to 66 Gy (median, 60 Gy). The post-implant efficacy was evaluated by response evaluation criteria in solid tumors (RECIST) version 1.1, and an adverse event was evaluated by the Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Score (EORTC). COX proportional hazards model was used to analyze risk factors affecting effectiveness.ResultsAmong 36 patients, 31 patients (86.1%) received fluorouracil-based chemotherapy (1-6 cycles) after 125I seed implantation. Local control rates at 3, 6, 12, and 24 months after implantation were 51%, 30%, 30%, and 18%, respectively, with a median of 9 months (95% CI: 6.106-11.894); survival rates after 3, 6, 12, and 24 months were 55%, 41%, 22%, and 22%, respectively, with a median of 8 months (95% CI: 5.753-10.247). Multivariate analysis showed that D90 and short-term efficacy were independent factors related to local control and survival rate (p = 0.005, < 0.001, 0.010, < 0.001). There were 2 cases (5.6%) with grade 1 skin toxicity, 1 case (2.8%) with grade 4 skin toxicity, 3 cases (8.3%) with grade 1 mucosal ulcer, and 3 cases (8.3%) with grade 1 xerostomia.Conclusions125I seed implantation as an effective salvage treatment shows definite efficacy and safety for patients with in-field cervical lymph node recurrence of ESCC after external beam radiation therapy.

Patient setup variations in computed tomography-based treatment planning for left-sided breast cancer using electronic portal images

Background and Aim: This study deals with isocentric variations along with the setup reproducibility and determines the random and systematic errors in a cohort of 25 (females) left-sided breast cancer patients treated with megavoltage X-rays using an online electronic portal imaging (EPI) protocol. Materials and Methods: This is a hospital-based cross-sectional observational study which was carried out on 25 female patients of carcinoma breast (left sided) who had undergone modified radical mastectomy. After completion of the planned chemotherapy, all patients underwent virtual three-dimensional (3D) computed tomography (CT) simulation, and an external beam radiotherapy treatment was planned on these 3D CT images on a treatment planning system (TPS) using two (coplanar)/conventional tangential fields for a total dose of 50 Gy in 25 fractions. Analysis of 150 EPIs determined changes in the treatment fields during setup of these 25 patients. The online assessment included setup deviations in all the three directions (anteroposterior [AP], superoinferior [SI], and mediolateral [ML]) and variations in central lung distance (CLD) during the first three fractions. Results: Random errors ranged from 1 to 5 mm for the chest wall (medial and lateral) tangential treatments and 1 mm for the anterior supraclavicular nodal field. Systematic errors ranged from 2.5 to 4.5 mm in the AP direction for the tangential fields and from 2.5 to 7.5 mm in the SI and Mediolateral directions for the anterior supraclavicular nodal field. For 25 (left-sided) patients, the CLD (TPS) was 20–30 mm, CLD (EPIs) was 25–40 mm showing variations of 5–10 mm, V20 was 1.0–6.0 Gy, maximum total lung dose was 43 Gy, V30 was 2.0–4.0 Gy, maximum heart dose was 52 Gy, and maximum spine dose was 45 Gy. Conclusions: Online assessment of patient position with matching of EPIs with digitally reconstructed radiographs is a useful method in evaluation of interfraction reproducibility of tangential fields in breast irradiation, thereby improving upon the quality of treatment delivery for our patient population.

Preliminary results of modified interstitial MIAMI brachytherapy applicator for treatment of upper and apical vaginal tumors.

PurposeIntracavitary vaginal brachytherapy (VBT) cylinders are limited in treating upper/apical vaginal disease due to the distance between the target and radiation source positions. Interstitial brachytherapy devices directly expose the vaginal mucosa to radiation sources, increasing morbidity. To target apical disease while limiting excessive treatment to the vaginal mucosa and organs at risk, we modified the commercially available multichannel MIAMI applicator, allowing the direct extension of needles into the apex with the protection of cylinder.Material and methodsThe device has one central plastic core with six peripheral channels. The modified device permits titanium needles to surpass the apical surface into vaginal tissue. A retrospective analysis on thirteen patients treated with this device was conducted. Patient demographics, gross tumor volume (GTV)/clinical target volume (CTV), initial diagnosis and management, toxicity data, and EQD2 data for the bladder and rectum were obtained.ResultsThere were ten patients with vaginal recurrences and three with primary vaginal/cervical cancers. Mean dosage of VBT treatment was 25.5 Gy in 3-5 fractions. Mean dosage of external beam radiation therapy (EBRT) treatment was 44 Gy. Common acute toxicities included diarrhea, fatigue, cystitis, and nausea. Common chronic toxicities were pelvic pain, vaginal stenosis, and skin telangiectasia. Mean EQD2 dose for bladder and rectum were 72.3 Gy and 62.3 Gy, respectively. Ten patients had no evidence of relapse, two suffered from distant metastases, and one patient with stage IIIA cervical adenocarcinoma had loco-regional recurrence seventeen months after radiation treatment.ConclusionsOur data suggests that the custom applicator is associated with robust dosimetric coverage, good loco-regional control, acceptable toxicity, and reduced tissue trauma. This device allows treatment of apically located vaginal tumors without significant damage to the vaginal vault and organs at risk. Additionally, it provides the flexibility to treat multiple patients with variable vaginal diameters and sizes/depths of apical tumors using a single device.

Haemoptysis: a presentation of papillary thyroid carcinoma

Papillary thyroid carcinomas can be retrospectively diagnosed in patients, who are having metastatic disease with an occult primary lesion. A sixty-year-old female patient was investigated for haemoptysis and was found to have a tracheal lesion. Biopsy revealed a papillary carcinoma of the thyroid. Patient underwent total thyroidectomy with excision of the tracheal lesion and was followed up by adjuvant external beam radiotherapy (EBRT) and radioactive iodine (RAI) treatment. The detailed history, examination and investigations of neck and upper aerodigestive tract (ADT) are important for correct diagnosis of papillary thyroid microcarcinoma.

Prostate Margin Reduction for External Beam Radiation Therapy Treatment of high-risk Prostate Cancer Including Pelvic Lymph Nodes

Bone has been used as an image guidance surrogate for prostate and pelvic lymph node (PLN) radiotherapy. Despite the independent motion of the prostate from bone, recent study has demonstrated that adequate dose could be delivered to this target when a 10mm margin except 7mm posteriorly is used to expand the PTV. This study explored the feasibility of reducing the margin by assessing the dosimetric impact on prostate and organ at risks.

Brachytherapy with surgical resection as salvage treatment for recurrent high-grade meningiomas: a matched cohort study.

To evaluate surgical resection with brachytherapy placement as a salvage treatment in patients with recurrent high-grade meningioma who exhausted prior external beam treatment options. Single-center retrospective review of our institutional experience of brachytherapy implantation from 2012 to 2018. The primary outcome of the study was progression free survival (PFS). Secondary outcomes included overall survival (OS) and complications. A matched cohort of patients not treated with brachytherapy over the same time period was evaluated as a control group. All patients had received prior radiation treatment and underwent planned gross total resection (GTR) surgery. A total of 27 cases were evaluated. Compared with prior treatment, brachytherapy implantation demonstrated a statistically significant improvement in tumor control [HR 0.316 (0.101 - 0.991), p = 0.034]. PFS-6 and PFS-12 were 92.3% and 84.6%, respectively. Compared with the matched control cohort, brachytherapy treatment demonstrated improved PFS [HR 0.310 (0.103 - 0.933), p = 0.030]. Overall survival was not statistically significantly different between groups [HR 0.381 (0.073 - 1.982), p = 0.227]. Overall postoperative complications were comparable between groups, although there was a higher incidence of radiation necrosis in the brachytherapy cohort. Brachytherapy with planned GTR improved PFS in recurrent high-grade meningioma patients who exhausted prior external beam radiation treatment options. Future improvement of brachytherapy dose delivery methods and techniques may continue to prolong control rates and improve outcomes for this challenging group of patients.

Gemcitabine potentiates the anti-tumour effect of radiation on medullary thyroid cancer.

Patients with medullary thyroid cancer (MTC) are often diagnosed with spread tumour disease and the development of better systemic treatment options for these patients is important. Treatment with the radiolabelled somatostatin analogue 177Lu-octreotate is already a promising option but can be optimised. For example, combination treatment with another substance could increase the effect on tumour tissue. Gemcitabine is a nucleoside analogue that has been shown to sensitise tumour cells to radiation. The aim of this study was to investigate potentially additive or synergistic effects of combining radiation with gemcitabine for treatment of MTC. Nude mice transplanted with patient-derived MTC tumours (GOT2) were divided into groups and treated with radiation and/or gemcitabine. Radiation treatment was given as 177Lu-octreotate or external beam radiotherapy (EBRT). The volume of treated and untreated tumours was followed. The absorbed dose and amount of gemcitabine were chosen to give moderate tumour volume reduction when given as monotherapy to enable detection of increased effects from combination treatment. After follow-up, the mice were killed and tumours were immunohistochemically (IHC) analysed. Overall, the animals that received a combination of EBRT and gemcitabine showed the largest reduction in tumour volume. Monotherapy with EBRT or gemcitabine also resulted in a clear detrimental effect on tumour volume, while the animals that received 177Lu-octreotate monotherapy showed similar response as the untreated animals. The GOT2 tumour was confirmed in the IHC analyses by markers for MTC. The IHC analyses also revealed that the proliferative activity of tumour cells was similar in all tumours, but indicated that fibrotic tissue was more common after EBRT and/or gemcitabine treatment. The results indicate that an additive, or even synergistic, effect may be achieved by combining radiation with gemcitabine for treatment of MTC. Future studies should be performed to evaluate the full potential of combining 177Lu-octreotate with gemcitabine in patients.

Fast automated multi-criteria planning for HDR brachytherapy explored for prostate cancer

We developed a fast and fully-automated, multi-criteria treatment planning workflow for high dose rate brachytherapy (HDR-BT). In this workflow, the patient-CT with catheter reconstructions and dwell positions are imported from the clinical TPS into a novel system for automated dwell time optimisation. The optimised dwell times are then imported into the clinical TPS. The aims of automation were (1) planner-independent, enhanced plan quality, (2) short optimisation times.Our in-house developed system for fully automated, multi-criteria external beam radiotherapy (EBRT) treatment planning (Erasmus-iCycle) was adapted for optimisation of HDR-BT dose distributions. The investigations were performed with planning CT scans with catheter reconstructions and delineations of twenty-five low- and intermediate-risk prostate cancer patients who were previously treated in our center with Gy HDR-BT. Automatically generated plans (autoplans) were compared to the corresponding clinical plans. All evaluations were performed in the clinical TPS.The requested 95% tumour coverage was obtained for all autoplans, while this was only observed in 23/25 clinical plans. All autoplans showed a consistent reduction of the for the highest prioritised OAR, the urethra. The average and maximum reductions were 6.3%-point and 12.1%-point of the prescribed dose, respectively. In addition, conformality of the autoplans was higher. The autoplans had slightly smaller delivery times. Autoplanning took on average 4.6 s, including computation of the dose kernels.

Radiation-Induced Amplification of TGFB1-Induced Mesenchymal Stem Cell-Mediated Sodium Iodide Symporter (NIS) Gene 131I Therapy.

The innate tumor homing potential of mesenchymal stem cells (MSCs) has been used for a targeted delivery of the theranostic sodium iodide symporter (NIS) transgene into solid tumors. We have previously shown that external beam radiotherapy (EBRT) results in the enhanced recruitment of NIS-expressing MSCs into human hepatocellular carcinoma (HuH7). In parallel, the tumor-associated cytokine TGFB1 becomes strongly upregulated in HuH7 tumors in response to EBRT. We therefore evaluated the effects of combining focused EBRT (5 Gy) with MSC-mediated systemic delivery of the theranostic NIS transgene under control of a synthetic TGFB1-inducible SMAD-responsive promoter (SMAD-NIS-MSCs) using 123I-scintigraphy followed by 131I therapy in CD1 nu/nu mice harboring subcutaneous human hepatocellular carcinoma (HuH7). Following tumor irradiation and SMAD-NIS-MSC application, tumoral iodide uptake monitored in vivo by 123I-scintigraphy was enhanced as compared with nonirradiated tumors. Combination of EBRT and SMAD-NIS-MSC-mediated 131I therapy resulted in a significantly improved delay in tumor growth and prolonged survival in therapy mice as compared with the combined therapy using CMV-NIS-MSCs or to control groups receiving EBRT or saline only, or EBRT together with SMAD-NIS-MSCs and saline applications. MSC-based NIS-mediated 131I therapy after EBRT treatment dramatically enhanced therapeutic efficacy when a TGFB1-inducible SMAD-responsive promoter was used to drive NIS expression in adoptively applied MSCs. The remarkable therapeutic effect seen is thought to be linked in large part to the enhanced TGFB1 produced in this context, which leads to a highly selective and focused amplification of MSC-based NIS expression within the tumor milieu.

IPEM Topical Report: A 2018 IPEM survey of MRI use for external beam radiotherapy treatment planning in the UK

The benefits of integrating MRI into the radiotherapy pathway are well published, however there is little consensus in guidance on how to commission or implement its use. With a view to developing consensus guidelines for the use of MRI in external beam radiotherapy (EBRT) treatment planning in the UK, a survey was undertaken by an Institute of Physics and Engineering in Medicine (IPEM) working-party to assess the current landscape of MRI use in EBRT in the UK.A multi-disciplinary working-party developed a survey to understand current practice using MRI for EBRT treatment planning; investigate how MRI is currently used and managed; and identify knowledge gaps. The survey was distributed electronically to radiotherapy service managers and physics leads in 71 UK radiotherapy (RT) departments (all NHS and private groups).The survey response rate was 87% overall, with 89% of NHS and 75% of private centres responding. All responding centres include EBRT in some RT pathways: 94% using Picture Archiving and Communication System (PACS) images potentially acquired without any input from RT departments, and 69% had some form of MRI access for planning EBRT. Most centres reporting direct access use a radiology scanner within the same hospital in dedicated (26%) or non-dedicated (52%) RT scanning sessions. Only two centres reported having dedicated RT MRI scanners in the UK, lower than reported in other countries. Six percent of radiotherapy patients in England (data not publically available outside of England) have MRI as part of their treatment, which again is lower than reported elsewhere. Although a substantial number of centres acquire MRI scans for treatment planning purposes, most centres acquire less than five patient scans per month for each treatment site. Commissioning and quality assurance of both image registration and MRI scanners was found to be variable across the UK. In addition, staffing models and training given to different staff groups varied considerably across the UK, reflecting the current lack of national guidelines.The primary barriers reported to MRI implementation in EBRT planning included costs (e.g. lack of a national tariff for planning MRI), lack of MRI access and/or capacity within hospitals. Despite these challenges, significant interest remains in increasing MRI-assisted EBRT planning over the next five years.

Effect of Radiation Dose to Cardiac Substructures on the Acute Development of New Arrhythmias Following Conventionally Fractionated Radiation Treatment to the Lung

The impact of radiation dose on specific cardiac substructures and its relationship with the development of new cardiac arrhythmias in the acute setting (either during the radiation treatment course itself, or within the month immediately following completion of treatment) is not well-established in the existing literature. We aimed to identify patients who experienced acute cardiac arrhythmic toxicities and determine the dose received by the sinoatrial (SA) node and right atrium in these patients. We conducted a single-institution, retrospective review of patients who received at least 45 Gy of external-beam radiation treatment to the lung between October 2013 and June 2017. 193 patients were identified within this cohort, and these patients’ medical records were reviewed for incidence of new cardiac events during or after radiation treatment. Seven patients were identified as having suffered a Grade 3 acute cardiac arrhythmic toxicity requiring inpatient admission, all of whom had no prior history of arrhythmias. Contouring guidelines for regional cardiac anatomy were created, and cardiac substructures, including the SA node and all four main chambers of the heart, were contoured on these patients. An analysis of the dose received by the SA node and the right atrium, two substructures critical to the electrical conduction system of the heart, was subsequently completed on this patient subset. Of the seven patients with an acute cardiac arrhythmic toxicity, the median age was 65 and the median follow-up from conclusion of radiation treatment was 17 months. The median prescribed dose was 60 Gy in 30 fractions. Two of the patients were prescribed radiation for left-sided lung malignancies, and the other five were treated for right-sided cancers. Two of the seven patients experienced cardiac toxicity during the treatment course, while the other five experienced toxicities within the month following conclusion of radiation. Four of the seven patients experienced atrial fibrillation, and the remaining toxicities (one in each patient) were Mobitz Type 2 heart block, multifocal atrial tachycardia, and atrial flutter. Across all seven patients, the mean SA node dose ranged from 1702 cGy to 6778 cGy and the maximum SA node dose ranged from 3157 cGy to 6904 cGy; the mean right atrial dose ranged from 443 cGy to 4057 cGy and the maximum right atrial dose ranged from 3620 cGy to 6938 cGy. Three patients received over 60 Gy of mean SA node dose, maximum SA node dose, and maximum right atrium dose. While acute development of new cardiac arrhythmias following conventionally fractionated radiation treatment to the lung is an uncommon occurrence, increased radiation dose to the SA node and right atrium may predispose patients to this toxicity; further study is warranted to elucidate specific dose limits to cardiac substructures.

Risk of Subsequent Primary Cancers After External Beam Radiotherapy Treatment of Pediatric Low Grade Gliomas: A Surveillance, Epidemiology, and End Results Analysis 1973 to 2015

Abstract INTRODUCTION Past studies have associated external beam radiotherapy (EBRT) with higher incidences of subsequent primary malignancies (SPMs). This link has been documented for leukemias, and prostate, thyroid, and bone cancers. However, the effects of EBRT on SPM development from low grade gliomas (LGGs) are not well understood. The aim of the present study was to characterize the risk of SPM development after EBRT treatment of LGGs. METHODS A total of 1439 pediatric (age 0-17) records between 1973 and 2015 were assembled from the Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable Cox regressions were used to evaluate the prognostic impact of demographic, tumor, and treatment-related covariates. Propensity score matching was used to balance baseline characteristics. Survival and cumulative hazard analyses measured the time to, and risk of, SPM development, stratified by receipt of EBRT. RESULTS Of the 1439 pediatric patients we analyzed, 450 received EBRT and 989 did not. A total of 65 pediatric patients were identified who developed SPMs after LGG diagnosis, and 35 of these patients received EBRT (OR: 2.70). Unadjusted Cox regressions revealed a significantly elevated SPM risk in EBRT-treated pediatric patients with LGGs (HR: 2.22, CI: 1.34-3.67). After adjusting for covariates such as race, gender, income, chemotherapy, and grade (World Health Organization I vs II), there was still a clear association between EBRT and the development of SPMs (HR: 2.52, CI: 1.50-4.23). Propensity score matching across covariates did not significantly impact the hazard ratio. Time-to-event Kaplan Meier curves demonstrated earlier SPM development in the EBRT-treated LGG pediatric population, and Nelson–Aalen cumulative hazard estimates showed higher incidences of SPM development at all time points. CONCLUSION EBRT treatment for LGGs is associated with an elevated incidence of SPMs, even after controlling for available covariates. This suggests less aggressive EBRT use in the pediatric LGG population may be warranted.

Patient-reported health-related quality of life up to three years after the treatment with permanent brachytherapy: Outcome of the large-scale, prospective longitudinal study in Japanese–Prostate Cancer Outcome Study by Permanent I-125 Seed Implantation (J-POPS)

PurposeTo evaluate long-term health-related quality of life (HRQOL) impact of I-125 permanent seed implantation (PI) in Japanese patients with localized prostate cancer. Materials and MethodsThis is a longitudinal, prospective study of 2353 patients who enrolled in the nationwide Japanese–Prostate Cancer Outcome Study by Permanent I-125 Seed Implantation (J-POPS) from July 2005 to June 2007. HRQOL was measured before and after treatment (3, 12, 24, and 36 months) using the Medical Outcomes Study 8-items Short-Form Health Survey (SF-8) and the Expanded Prostate Cancer Index Composite Japanese version questionnaire. ResultsOf the total of 1511 patients who returned anonymized HRQOL questionnaires to Translational Research Center for Medical Innovation, 1079 underwent PI alone (PI group) and 432 underwent combined PI and external beam radiation therapy (EBRT) treatment (EBRT combination therapy group). The mental component summary score of SF-8 was improved at 12, 24, and 36 months compared with the pretreatment level. Although the urinary summary score at 3 months in the PI group was significantly lower than that in the EBRT combination therapy group, which recovered thereafter and was comparable to the score of the EBRT combination therapy group. The bowel summary score in the PI group was significantly higher than that in the EBRT combination therapy group at 12, 24, and 36 months. ConclusionThis longitudinal, large-scale prospective study indicated that the general HRQOL for PI was almost maintained 3 years after treatment. These results provide important information for patients with localized prostate cancer, who may select to receive I-125 brachytherapy.

Radioiodine therapy of advanced differentiated thyroid cancer: clinical considerations and multidisciplinary approach.

Differentiated thyroid cancer (DTC) accounts for 95% of all thyroid cancers and is generally an indolent tumor, treated effectively with surgery, radioactive iodine, and thyroid-stimulating hormone suppressive therapy. However, 5-10% of patients have advanced disease, with aerodigestive tract invasion, distant metastases, or radioiodine refractory disease, with poor prognosis. This review focuses on the approaches for treating advanced DTC, including management of gross extra-thyroidal extension, recurrent loco-regional or distant metastatic disease, the role of external beam radiation therapy and systemic treatment. Locally ablative treatment modalities, including surgery, radiation therapy, and thermal ablation are evolving and can be used in selected patients. In recent years, new therapeutic agents with molecular targets have become available and two multi-kinase inhibitors, sorafenib and lenvatinib, have been licensed for iodine refractory DTC showing an advantage in terms of progression-free survival, although an impact on overall survival has not been proven yet and remarkable side-effects emerged. Management of advanced thyroid cancer can be challenging but a multidisciplinary approach can significantly improve outcomes for this patient population.

Evaluating the Impact of Post-Treatment Self-Management Guidelines for Prostate Cancer Survivors

BackgroundWith a rising number of prostate cancer survivors, transitioning patients to follow-up care has become more relevant in the current Albertan cancer care landscape and has led to a need for better patient education resources surrounding this topic. In response, the Alberta Provincial Genitourinary Tumour Team and Cancer Control Alberta have developed self-management guidelines to aid patients with prostate cancer during this transition. This study aimed to evaluate the effectiveness and impact of the new provincial self-management guidelines in facilitating transition from active curative external beam radiation treatment to primary community care. MethodsThis prospective study used convenience sampling to recruit 18 patients with prostate cancer from two major cancer centers in Alberta: Calgary and Edmonton. Participants were given the self-management guidelines within their final week of external beam radiation treatment and a follow-up phone questionnaire 4 weeks later. Participants answered standardized questions regarding the self-management document based on the themes of timeliness, patient-centeredness, safety, effectiveness, and comprehensiveness. Results and DiscussionA thematic analysis of the results suggested that the majority of patients were satisfied with the document in all domains, but some expressed concern with the clarity of the document. They suggested improvements such as adding a side effect timeline, adding an appendix or symptom index, further simplifying the language, and coordinating delivery of the guidelines with an in-person education session. ConclusionOverall, our findings supported the effectiveness of the guidelines in providing self-management information. If implemented into practice, these guidelines could have a positive impact on the perception of patients with prostate cancer regarding transitioning to follow-up care.

Differential vaginal wall dosing in high-dose rate brachytherapy for endometrial cancer: The potential for superior coverage of at-risk areas while preserving organs at risk—An analysis of simulated data.

e17121 Background: The treatment of curable endometrial cancer (EC)involves surgery with adjuvant radiotherapy. Histology of EC is a major determining factor for intracavitary brachytherapy (ICRT) treatment volume in early stage EC. Many guidelines recommend ICRT treatment of an extended volume up to the whole length of the vaginal stump (VS) for cases of high risk histologies (HRH) wherein a differential dosing of proximal and distal VS has the potential to achieve targeted therapeutic doses to at risk areas without compromise to critical structures.We present a simulated novel way to treat the VS by ICRT in cases of EC with HRH. Analysis of the simulated and approved plans allow us to compare the doses to organs at risk (OAR’s). Methods: Seventy-five cases from July 2017-August 2018 were reviewed and twenty-five (25) met the criteria for inclusion in this study. All these cases received External Beam Radiation Therapy (EBRT) dose of 50.4Gy/28. The ICRT simulation CT data-set was subsequently used to generate the study plan which was then compared to the actual treatment plan. In order to treat the whole VS but spare OARs a club-shaped design was proposed. This technique involved treating the upper 1/3 with a prescription point at 0.5cm lateral to the applicator surface and the lower 2/3 with a prescription point at the applicator surface. The length of the VS was defined from the tip of the applicator to 2cm superior to the introitus. The D2cc values for the contoured bladder and rectum were extracted from the treatment plan and used along with the D2cc values from the EBRT treatment to calculate OAR EQD2. QUANTEC Constraints used were (ICRU 83): EQD2 bladder: 90Gy; EQD2 rectum: 75Gy. Once calculated, the results were analyzed and the percent deviation between the proposed plan and the constraints as well as the approved plan were determined. Results: Twelve (12) of twenty-five (25) cases were HRH cases. The club-shaped design to treat the whole VS didn't further compromise the OAR (EQD2: 22% below constraints) or the rectum (EQD2: 1% below constraints). There was only a 2% difference between the final constraints in both treatment techniques. Conclusions: This technique to treat the full VS length can be used without adversely affecting OAR toxicities with superior coverage to at risk areas while maintaining dose constraints to OAR. Results, however, are limited by the small sample size.

Monte carlo study of organ doses and related risk for cancer in Tanzania from scattered photons in cervical radiation treatment involving Co-60 source

PurposeThe present work aimed to evaluate organ doses and related risk for cancer from external beam radiation treatment (EBRT) and high-dose-rate (HDR) brachytherapy (BT) involving Co-60 source for patients with cervical carcinoma in Tanzania based on Monte Carlo methods and to evaluate the secondary cancer risks in their lifetime. MethodsEBRT and HDR-BR were modelled by using the MCNPX Monte Carlo (MC) code. The MC simulations were performed by using validated models and isocentric irradiation of an adult female computational phantom. The organ doses and cancer risks estimates were obtained. ResultsThe highest absorbed doses of 6.98 × 10−2 and 5.74 × 10−2 Sv/Gy were recorded in the bladder for BT and EBRT. The higher risk was found for colon at 1.06 × 10−3 in the HDR-BT and 9.75 × 10−5 in the EBRT per 100,000 population at exposure age of 35 years than in the other organs. The risk magnitude decreased with increasing age at exposure. In general, the secondary cancer risks in all sites considered from EBRT and HDR-BR for cervical cancer patient were lower than the baseline risks. ConclusionsThe chances of developing secondary cancer take years following radiation therapy are extremely low, but the results of present study can support to establish a future database on secondary cancer risks involving radiation therapy in patients with cervical cancer by using HDR-BR and EBRT with Co-60 source in Tanzania and other developing countries.

Modern methods of external-beam radiation therapy in treatment of patients with hepatocellular carcinoma

Treatment of patients with hepatocellular carcinoma is an urgent problem of modern oncology. Despite the possibility of using various methods of local and systemic exposure and their continuous improvement, the results of treatment of patients with hepatocellular carcinoma in general remain unsatisfactory. Modern radiation therapy can be considered as one of the significant methods of local exposure due to relative efficacy and acceptable tolerability. Implementation of radiation treatment in the mode of stereotactic radiotherapy is a promising direction in the treatment of patients with hepatocellular carcinoma because of the possibility of applying ablative doses with a significant restriction of doses to healthy organs and tissues in a short period of time and the possibilities of combining this method with other variants of specific treatment.