Radiotherapy Dose Research Articles

Prognostic assessment of patients with bone metastatic renal cell cancer treated with palliative radiotherapy.

The present study investigated the prognosis of patients who received palliative radiotherapy (RT) for bone metastases (BMs) from renal cell cancer (RCC), and assessed the prognostic factors specific to BMs from RCC. A total of 109 patients with RCC and BMs who underwent RT for the first time were included in the study. Prognostic factors were evaluated using multivariate analysis and a scoring system based on regression coefficients was devised. The median follow-up time was 9 months, and the 0.5-year overall survival (OS) rate was 73.0%. In the multivariate analysis, the significant prognostic factors were higher performance status (≥2), no control of the primary site, disseminated metastasis, lymph node metastasis and multiple BMs. A score of 1 point was assigned to each risk factor. The median OS times were 19.0 and 5.0 months in patients with a total score of ≤1 (n=49) and >1 (n=60), respectively (P<0.01). In conclusion, a comprehensive prognostic assessment using these factors may be useful for predicting the prognoses of patients with BMs from RCC. In addition, this scoring system may be useful in selecting the optimal RT dose.

First-line treatment with KN046, chemotherapy and palliative radiotherapy for advanced esophageal squamous cell carcinoma: an open-label, dose escalation, and dose expansion phase Ib trial

There is growing evidence to suggest that radiotherapy might enhance the efficacy of immunotherapy. This study aimed to assess the possibility of KN046, a bispecific antibody targeting PD-L1 and CTLA-4, combined with chemotherapy and palliative radiotherapy for advanced esophageal squamous cell carcinoma (ESCC). In this open-label, phase Ib trial, patients with advanced ESCC were administered chemotherapy with palliative radiotherapy, and KN046 in the predefined escalation dosages of 1, 3, or 5 mg/kg (every 3 weeks during chemotherapy cycles and every 2 weeks during KN046 maintenance). The chemotherapy regimen constituted cisplatin (75 mg/m2 i.v., d1) and paclitaxel (135–175 mg/m2 ivgtt., d1). Radiotherapy specifics, including site, timing, dose, and fragmentation pattern, were at the investigator’s discretion. The primary outcome was dose-limiting toxicity (DLT). From May 2019 to April 2021, 25 patients were enrolled across the dosage groups: 3 in 1 mg/kg, 12 in 3 mg/kg, and 10 in 5 mg/kg. No DLT was observed during the dose escalation. The objective response rate was 41.7% (95%CI 22.1–63.4), while the disease control rate was 87.5% (95%CI 67.6–97.3). At a median follow-up of 11.8 months, the median progression-free survival was 7.8 months (95%CI 5.2–9.7) and median overall survival was 15.9 months (95%CI 8.4-NE). Serious adverse events were reported in 48.0% of patients, predominantly leukopenia (16%), immune-mediated enterocolitis (12%), immune-mediated pneumonitis (8%), and neutropenia (8%). Combining KN046 with chemotherapy and palliative radiotherapy might be feasible, showing a favorable safety profile and notable efficacy in advanced ESCC patients.

Effectiveness of microsurgical palatal tonsillectomy in patients with oropharyngeal cancer and metastases of squamous cell carcinoma into the cervical lymph nodes without identified primary lesion

Introduction. Metastasis without an identified primary lesion is an unresolved and complex problem in clinical oncology. The issue of the necessity of primary lesion identification remains controversial. According to some studies, detection of the primary tumor potentially reduces the dose of radiation therapy and therefore prevents development of toxic reactions that reduce the quality of life of the patient, and in some cases completely eliminates the need for adjuvant therapy. Widespread development and application of robotic, microsurgical, and laser transoral techniques make it possible to verify latent oropharyngeal cancer. The detection of overexpression of p16 protein in metastatic affected lymph nodes may indicate the association of this pathology with human papillomavirus.Aim. To investigate the efficacy of microsurgical palatal tonsillectomy (using a surgical microscope) in diagnosis and treatment of occult oropharyngeal cancer in patients with cervical lymph node metastases of undetected primary site, determine the frequency of expression of the surrogate marker of human papillomavirus – protein p16.Materials and methods. The study was based on the results of diagnosing 82 patients with cervical lymph node metastases of undetected primary site. The inclusion criteria were morphologically verified cervical lymph node metastases of squamous cell carcinoma, absence of a primary tumour after a standard clinical examination. 10 patients underwent palatal tonsillectomy using a surgical microscope and cervical lymph node dissection based on the results of clinical examination and instrumental diagnostics.Results. The use of microsurgical palatal tonsillectomy in patients with metastases of squamous cell carcinoma in the cervical lymph nodes without identified primary lesion allowed to diagnose cancer of the palatine tonsil in 12.1 % of cases, cancer of this location associated with human papilloma virus in 70 % of cases.Conclusion. Microsurgical palatal tonsillectomy using a surgical microscope allowed us to not only verify occult palatine tonsil cancer, but also to establish accurate diagnosis and stage of the disease with subsequent determination of the scope of adjuvant therapy.

Clinical target volume design and dose in carbon-ion radiation therapy for sinonasal mucosal melanoma

Background and purposeNo guidelines exist for the clinical target volume (CTV) and radiotherapy dose in sinonasal mucosal melanoma (SNMM). Thus, we aimed to determine the carbon-ion radiotherapy (CIRT) CTV and dose for SNMM. Materials and methodsIn total, 135 patients with SNMM who received CIRT were reviewed. The relative biological effectiveness-weighted dose was 57.6 or 64 Gy in 16 fractions. CTV was classified into small CTV, which included the gross tumor and visible melanosis with a certain margin, and extended CTV, which included the tumor site and adjacent anatomical structures. Local recurrence (LR) patterns were pattern I, II, and III, defined as recurrence over the gross tumor, visible melanosis and subclinical area, which would be covered if extended CTV was applied, and outside the extended CTV, respectively. ResultsThe 5-year LR rate was 35.3 %. The prescribed dose was not a significant risk factor for pattern I LR; however, 57.6 Gy for a large tumor was insufficient for local control. Using an extended CTV was significantly associated with a lower risk of pattern II LR, and these recurrences did not occur in regions that received > 40 Gy. The 5-year pattern III LR rate was 6.4 %. ConclusionUtilizing an extended CTV in CIRT for SNMM is appropriate even for small tumors. Using a smaller CTV after an extended CTV of at least 40 Gy is recommended to reduce adverse events. Although the optimal dose for gross tumors remains unclear, the latest technology with 64 Gy showed good outcomes.

National Cancer Database analysis of radiation therapy consolidation modality and dose for inoperable endometrial cancer

We utilized the National Cancer Database (NCDB) to evaluate trends and assess outcomes in radiation therapy (RT) boost modality and total dose among medically inoperable endometrial cancer (EC) patients with locoregional disease. Patients with International Federation of Gynecology and Obstetrics (FIGO) stage I - IIIC2 inoperable EC treated with RT ± chemotherapy were analyzed. Practice patterns compared external beam RT (EBRT) versus high-dose-rate brachytherapy (BT) boost and total RT dose (palliative: ≤3000 cGy, definitive low dose [DLD]: 4500 - 6249 cGy, definitive high dose [DHD]: ≥6250 cGy) over time. Kaplan-Meier method evaluated overall survival (OS) and Cox proportional hazard modeling assessed variables associated with OS. NCDB included 1755 total cases, of which 1209 received a radiotherapy boost. From 2004 to 2019, boost modality rates differed with increasing utilization of BT consolidation and a decreasing rate of palliation. Predictors of a palliative dose were stage III disease, Black race, N2 disease, and poorly or undifferentiated grade. Multivariable analysis found BT boost was associated with lower mortality compared to EBRT (HR: 0.81, CI: 0.68-0.97; p = 0.019). Mortality rates were higher for palliation versus DHD. Additional factors associated with inferior survival were increasing age, worse Charlson-Deyo score, higher T stage, higher N stage, and moderately, poorly, or undifferentiated grade. Utilization of BT boost for locoregionally confined, medically inoperable EC has increased since 2004. Brachytherapy consolidation remains an effective RT modality for medically inoperable EC, associated with lower mortality compared to EBRT consolidation.

Measurement of ionising radiation dose absorbed by bones by using a bone-imitating polymer gel dosimeter

Three-dimensional radiotherapy dosimetry allows for high-resolution dose distribution measurements using dosimeters imitating various tissues. This work concerns bone-imitating dosimeters. The following are investigated: (i) manufacturing of bone-imitating dosimeters with two types of calcium hydroxyapatite, (ii) dose response characteristics after irradiation with a 6 MV photon beam, and (iii) tissue equivalence. The main findings include the dosimetric compositions with two types of calcium hydroxyapatite. For 18 % of one type of hydroxyapatite, the dosimeter imitates trabecular bone. For much higher concentrations (>40 %, another hydroxyapatite), the dosimeter approaches the properties of dense bone. The dynamic dose response is not greater than 30 Gy, the linear dose range is <20 Gy (computed tomography and nuclear magnetic resonance measurements), and the dose sensitivity is 0.11–0.18 Gy−1 s −1 (nuclear magnetic resonance measurements) for different weight fractions of hydroxyapatites. In summary, a bone-imitating polymer gel dosimeter can be used to measure the radiation dose in radiotherapy.

Trends in the treatment of human papillomavirus-associated oropharyngeal carcinoma in Slovakia.

The optimal treatment of oropharyngeal cancer (OPC) associated with human papillomavirus (HPV) is currently a subject of clinical research. This questionnaire study investigated current trends in the treatment of HPV-associated (HPV+) OPC in Slovakia with the incorporation of deintensification of oncological treatment into routine clinical practice outside of clinical trials. The Slovak Cooperative Head and Neck Cancer Group (SCHNCG) developed a questionnaire aimed at identifying trends in the oncological treatment of HPV+ OPC intended for all radiation oncology (RO) facilities in Slovakia. Specialists in the field of RO responded to general questions about the character of their individual institutions as well as to 4 theoretical clinical scenarios (case reports) regarding the treatment of HPV+ OPC, focusing primarily on the applied dose of radiotherapy (RT), the extent of target volumes, and the type of concurrent chemotherapy (CHT). The questionnaire study involved 35 RO specialists from 14 institutions in Slovakia. Regarding primary chemoradiotherapy (CRT) in T1N1M0 HPV+ OPC, 16 respondents (45.7%) would consider de-escalation of the RT dose to <70 Gy. In the case of postoperative RT in pT1pN1M0 HPV+ OPC with negative resection margins (R0) and absent extracapsular extension (ECE), 4 physicians (11.4%) would consider de-escalation of the RT dose to <60 Gy in the tumor bed area, while the majority of the treating specialists (n=19, 54.3%) would omit concurrent CHT. In the case of primary RT in elderly patient with T2N1M0 HPV+ OPC, the same number of physicians (n=16, 45.7%) would consider de-escalation of the RT dose to <70 Gy, and 14 respondents (40.0%) would completely omit CHT. In a high-risk patient with T2N3M0 HPV+ OPC with a complete response after 3 cycles of induction chemotherapy (iCHT), none of the respondents would indicate a reduction in the RT dose to the area of the original tumor and lymphadenopathy to <60 Gy. The doses and extent of irradiated volumes in the treatment of HPV+ OPC in Slovakia vary among different institutions. The tendency to de-escalate RT doses and reduce doses of concurrent systemic therapy in Slovakia is high and there was also an observed trend to reduce the extent of radiation treatment fields.

Cardiac Substructure Radiation Dose and Associations With Tachyarrhythmia and Bradyarrhythmia After Lung Cancer Radiotherapy

BackgroundArrhythmias are common following radiotherapy for non–small cell lung cancer. ObjectivesThe aim of this study was to analyze the association of distinct arrhythmia classes with cardiac substructure radiotherapy dose. MethodsA retrospective analysis was conducted of 748 patients with locally advanced non–small cell lung cancer treated with radiotherapy. Cardiac substructure dose parameters were calculated. Receiver-operating characteristic curve analyses for predictors of Common Terminology Criteria for Adverse Events grade ≥3 atrial fibrillation (AF), atrial flutter, non-AF and non–atrial flutter supraventricular tachyarrhythmia (SVT), bradyarrhythmia, and ventricular tachyarrhythmia (VT) or asystole were calculated. Fine-Gray regression models were performed (with noncardiac death as a competing risk). ResultsOf 748 patients, 128 (17.1%) experienced at least 1 grade ≥3 arrhythmia, with a median time to first arrhythmia of 2.0 years (Q1-Q3: 0.9-4.2 years). The 2-year cumulative incidences of each arrhythmia group were 8.0% for AF, 2.7% for atrial flutter, 1.8% for other SVT, 1.4% for bradyarrhythmia, and 1.1% for VT or asystole. Adjusting for baseline cardiovascular risk, pulmonary vein (PV) volume receiving 5 Gy was associated with AF (subdistribution HR [sHR]: 1.04/mL; 95% CI: 1.01-1.08; P = 0.016), left circumflex coronary artery volume receiving 35 Gy with atrial flutter (sHR: 1.10/mL; 95% CI: 1.01-1.19; P = 0.028), PV volume receiving 55 Gy with SVT (sHR: 1.03 per 1%; 95% CI: 1.02-1.05; P < 0.001), right coronary artery volume receiving 25 Gy with bradyarrhythmia (sHR: 1.14/mL; 95% CI: 1.00-1.30; P = 0.042), and left main coronary artery volume receiving 5 Gy with VT or asystole (sHR: 2.45/mL; 95% CI: 1.21-4.97; P = 0.013). ConclusionsThis study revealed pathophysiologically distinct arrhythmia classes associated with radiotherapy dose to discrete cardiac substructures, including PV dose with AF and SVT, left circumflex coronary artery dose with atrial flutter, right coronary artery dose with bradyarrhythmia, and left main coronary artery dose with VT or asystole, guiding potential risk mitigation approaches.

AB079. Whole-brain radiotherapy versus high dose chemotherapy with autologous stem-cell transplantation for consolidation therapy in primary central nervous system lymphoma.

Whole brain radiotherapy (WBRT) is commonly used as consolidation therapy in primary central nervous system lymphoma (PCNSL). However, high-dose chemotherapy followed by autologous stem cell transplantation (HD-ASCT) has emerged as an alternative approach for PCNSL. This systematic review aims to assess the efficacy and safety of both treatment modalities. The systematic review follows PRISMA guidelines. A comprehensive search strategy identified relevant studies from PubMed, Europe PMC, and Cochrane Library. The following search terms were used: "primary central nervous system lymphoma", "Autologous Stem Cell Transplantation", and "whole-brain radiotherapy". We included randomized controlled trials (RCTs) cohort studies evaluating the use of whole-brain radiotherapy and high-dose chemotherapy followed by autologous stem cell transplantation in the treatment of histologically-confirmed PCNSL. Publications included were limited to English language full texts that were published in the past 10 years. Data extraction & manuscript quality assessment was done by two independent reviewers with a third reviewer to resolve any discrepancy. Primary outcomes include overall survival (OS), progression-free survival (PFS) & treatment related toxicity (TRT). Secondary outcomes were clinical neurological function and performance score assessments. Individual studies were assessed using the Jadad Scale and the Newcastle-Ottawa Scale for observational studies. We identified 5 studies, consisting of 2 RCTs and 3 cohort studies. After all studies considered, analysis revealed that consolidation therapy with HD-ASCT had a better overall PFS and OS compared to whole-brain radiotherapy (P<0.005). Both groups showed similar TRT with mostly haematological toxicity. Holistically clinical cognitive functions are found to be improved in HD-ASCT Patients and poorer results are exhibited by WBRT patients primarily in executive functions. Performance statuses are scored differently across all studies with slightly preferable results shown in patients treated with HDC-ASCT. Based on the findings of this systematic review, HDC-ASCT might be a preferable choice of consolidative therapy as shown with better OS, PFS with similar TRT. While WBRT are more feasible and cost-efficient, risks of cognitive impairment and reduced performance status after WBRT should be considered for further treatment choices. Further randomized clinical trials with a similar scoring system are needed.

The impact of cancer patient pathway on timing of radiotherapy and survival: a cohort study in glioblastoma patients.

Glioblastoma (GBM) is an aggressive brain tumor in which primary therapy is standardized and consists of surgery, radiotherapy (RT), and chemotherapy. However, the optimal time from surgery to start of RT is unknown. A high-grade glioma cancer patient pathway (CPP) was implemented in Norway in 2015 to avoid non-medical delays and regional disparity, and to optimize information flow to patients. This study investigated how CPP affected time to RT after surgery and overall survival. This study included consecutive GBM patients diagnosed in South-Eastern Norway Regional Health Authority from 2006 to 2019 and treated with RT. The pre CPP implementation group constituted patients diagnosed 2006-2014, and the post CPP implementation group constituted patients diagnosed 2016-2019. We evaluated timing of RT and survival in relation to CPP implementation. A total of 1212 patients with GBM were included. CPP implementation was associated with significantly better outcomes (p < 0.001). Median overall survival was 12.9 months. The odds of receiving RT within four weeks after surgery were significantly higher post CPP implementation (p < 0.001). We found no difference in survival dependent on timing of RT below 4, 4-6 or more than 6 weeks (p = 0.349). Prognostic factors for better outcomes in adjusted analyses were female sex (p = 0.005), younger age (p < 0.001), solitary tumors (p = 0.008), gross total resection (p < 0.001), and higher RT dose (p < 0.001). CPP implementation significantly reduced time to start of postoperative RT. Survival was significantly longer in the period after the CPP implementation, however, timing of postoperative RT relative to time of surgery did not impact survival.

Improving 3D dose prediction for breast radiotherapy using novel glowing masks and gradient-weighted loss functions.

The quality of treatment plans for breast cancer can vary greatly. This variation could be reduced by using dose prediction to automate treatment planning. Our work investigates novel methods for training deep-learning models that are capable of producing high-quality dose predictions for breast cancer treatment planning. The goal of this work was to compare the performance impact of two novel techniques for deep learning dose prediction models for tangent field treatments for breast cancer. The first technique, a "glowing" mask algorithm, encodes the distance from a contour into each voxel in a mask. The second, a gradient-weighted mean squared error (MSE) loss function, emphasizes the error in high-dose gradient regions in the predicted image. Four 3D U-Net deep learning models were trained using the planning CT and contours of the heart, lung, and tumor bed as inputs. The dataset consisted of 305 treatment plans split into 213/46/46 training/validation/test sets using a 70/15/15% split. We compared the impact of novel "glowing" anatomical mask inputs and a novel gradient-weighted MSE loss function to their standard counterparts, binary anatomical masks, and MSE loss, using an ablation study methodology. To assess performance, we examined the mean error and mean absolute error (ME/MAE) in dose across all within-body voxels, the error in mean dose to heart, ipsilateral lung, and tumor bed, dice similarity coefficient (DSC) across isodose volumes defined by 0%-100% prescribed dose thresholds, and gamma analysis (3%/3mm). The combination of novel glowing masks and gradient weighted loss function yielded the best-performing model in this study. This model resulted in a mean ME of 0.40%, MAE of 2.70%, an error in mean dose to heart and lung of -0.10 and 0.01Gy, and an error in mean dose to the tumor bed of -0.01%. The median DSC at 50/95/100% isodose levels were 0.91/0.87/0.82. The mean 3D gamma pass rate (3%/3mm) was 93%. This study found the combination of novel anatomical mask inputs and loss function for dose prediction resulted in superior performance to their standard counterparts. These results have important implications for the field of radiotherapy dose prediction, as the methods used here can be easily incorporated into many other dose prediction models for other treatment sites. Additionally, this dose prediction model for breast radiotherapy has sufficient performance to be used in an automated planning pipeline for tangent field radiotherapy and has the major benefit of not requiring a PTV for accurate dose prediction.

Protective effect of melatonin against radiobiological damage in the brain of rats exposed to low and high dose rate radiotherapy

This study aimed to investigate the radioprotective effect of melatonin (MLT) on brain damage in rats exposed to low and high dose rate radiotherapy. The dose rates of 10 MV photon beams used in the study were 600 MU/min and 2400 MU/min for low dose rate radiotherapy (LDR_RT) and high dose rate radiotherapy (HDR_RT), respectively. A total of 46 female Wistar albino rats aged between 8 and 12 weeks were divided in 6 groups. These groups were control, MLT, LDR_RT, HDR_RT, LDR_RT plus MLT and HDR_RT plus MLT, respectively. Rats in the radiation group received 16 Gy single dose whole body radiotherapy. Rats in the LDR_RT plus MLT and HDR_RT plus MLT groups received 10 mg/kg melatonin by intraperitoneal injection 15 min before radiotherapy. The rats were sacrificed 48 h after radiotherapy. Biochemical and histopathological methods analyzed radiation damage in rats. There was a statistically significant difference between the LDR_RT and HDR_RT radiation groups and the control group in terms of biochemical and histopathological parameters (p < 0.05). In the groups that received only LDR_RT and HDR_RT, the moderate neuro-degeneration scores were 1 and 4, respectively, while the moderate neuro-degeneration scores were 0 and 2 when MLT was applied to these groups. Superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) enzymes were decreased due to radiotherapy, whereas these enzymes were improved in MLT-treated groups. In conclusion, melatonin was found to be effective as a radioprotective agent in the prevention of brain damage caused by exposure to 10 MV photon radiation at dose rates of 600 MU/min and 2400 MU/min.

The Landscape of Stereotactic Ablative Radiotherapy (SABR) for Renal Cell Cancer (RCC).

Renal cell cancer (RCC) has traditionally been considered radioresistant. Because of this, conventional radiotherapy (RT) has been predominantly relegated to the palliation of symptomatic metastatic disease. The implementation of stereotactic ablative radiotherapy (SABR) has made it possible to deliver higher ablative doses safely, shifting the renal radioresistance paradigm. SABR has increasingly been adopted into the multidisciplinary framework for the treatment of locally recurrent, oligoprogressive, and oligometastatic disease. Furthermore, there is growing evidence of SABR as a non-invasive definitive therapy in patients with primary RCC who are medically inoperable or who decline surgery, unsuited to invasive ablation (surgery or percutaneous techniques), or at high-risk of requiring post-operative dialysis. Encouraging outcomes have even been reported in cases of solitary kidney or pre-existing chronic disease (poor eGFR), with a high likelihood of preserving renal function. A review of clinical evidence supporting the use of ablative radiotherapy (SABR) in primary, recurrent, and metastatic RCC has been conducted. Given the potential immunogenic effect of the high RT doses, we also explore emerging opportunities to combine SABR with systemic treatments. In addition, we explore future directions and ongoing clinical trials in the evolving landscape of this disease.

Echocardiographic Functional Outcomes Following Regional Nodal Irradiation for Breast Cancer Using Volumetric Modulated Arc Therapy

Regional nodal irradiation (RNI) for breast cancer yields improvements in disease outcomes, yet comprehensive target coverage often increases cardiac radiation therapy (RT) dose. Volumetric modulated arc therapy (VMAT) may mitigate high-dose cardiac exposure, although it often increases the volume of low-dose exposure. The cardiac implications of this dosimetric configuration (in contrast to historic 3D conformal techniques) remain uncertain. Eligible patients receiving adjuvant RNI using VMAT for locoregional breast cancer were prospectively enrolled in an IRB-approved study. Echocardiograms were performed prior to RT, at the conclusion of RT, and 6 months following RT. Echocardiographic parameters were measured by a single reader and measures were compared pre- and post-RT via the signed-rank test. Changes in echocardiographic parameters over time were compared to mean and max heart doses via the Spearman correlation test. Among 19 evaluable patients (median age 38 years), 89% (n = 17) received doxorubicin and 37% (n = 7) received trastuzumab/pertuzumab combination therapy. All patients received VMAT-based whole-breast/chest wall and RNI. The average mean heart dose was 456 cGy (range, 187-697 cGy) and the average max heart dose was 3001 cGy (1560-4793 cGy). Among salient echocardiographic parameters, no significant decrement in cardiac function was observed when comparing pre-RT to 6 months post-RT: mean left ventricular ejection fraction (LVEF) was 61.8% (SD 4.4%) pre-RT and 62.7% (SD 3.8%) 6 months post-RT (P = .493); mean global longitudinal strain (GLS) was -19.3% (SD 2.2%) pre-RT and -19.6% (SD 1.8%) 6 months post-RT (P = .627). No individual patient exhibited reduced LVEF or sustained decrement in GLS. No correlations were observed for changes in LVEF or GLS when compared to mean or maximum heart doses (P > .1 for all). VMAT for left-sided RNI yielded no significant early decrement in echocardiographic parameters of cardiac function, including LVEF and GLS, within this limited cohort. No patient exhibited significant LVEF changes, and none exhibited sustained decrements in GLS. VMAT may be a reasonable approach to cardiac avoidance in patients requiring RNI, including those receiving anthracyclines and HER2-directed therapy. Larger cohorts with longer follow-ups will be needed to validate these findings.

A feasibility study of dosimetry for breast cancer radiotherapy based on body surface changes.

The requirement for precise and effective delivery of the actual dose to the patient grows along with the complexity of breast cancer radiotherapy. Dosimetry during treatment has become a crucial component of guaranteeing the efficacy and security. To propose a dosimetry method during breast cancer radiotherapy based on body surface changes. A total of 29 left breast cancer radiotherapy cases were retroactively retrieved from an earlier database for analysis. Non-rigid image registration and dose recalculation of the planning computed tomography (CT) referring to the Cone-beam computed tomography were performed to obtain dose changes. The study used 3D point cloud feature extraction to characterize body surface changes. Based on the correlation proof, a mapping model is developed between body surface changes and dose changes using neural network framework. The MSE metrics, the Euclidean distances of feature points and the 3D gamma pass rate metric were used to assess the prediction accuracy. A strong correlation exist between body surface changes and dose changes (first canonical correlation coefficient=0.950). For the dose deformation field and dose amplitude difference in the test set, the MSE of the predicted and actual values were 0.136 pixels and 0.229 cGy, respectively. After deforming the planning dose into a deformed one, the feature points' Euclidean distance between it and the recalculated dose changes from 9.267±1.879mm to 0.456±0.374mm. The 3D gamma pass rate of 90% or higher for the 2mm/2% criteria were achieved by 80.8% of all cases, with a minimum pass rate of 75.9% and a maximum pass rate of 99.6%. Pass rate for the 3mm/2% criteria ranged from 87.8% to 99.8%, with 92.3% of the cases having a pass rate of 90% or higher. This study provides a dosimetry method that is non-invasive, real-time, and requires no additional dose for breast cancer radiotherapy.

Effectiveness and feasibility of selective intra-arterial low dose of cisplatin infusion and concomitant radiotherapy for patients with advanced laryngeal cancer with impaired renal function: A retrospective cohort study.

Chemoradiation therapy with high-dose cisplatin is the standard regimen against advanced squamous cell carcinoma of the larynx (SCC-L). However, patients with renal dysfunction are ineligible for this regimen. We investigated the effectiveness and feasibility of selective intra-arterial low-dose cisplatin infusion and radiotherapy (modified [m]-RADPLAT) for patients with impaired renal function. We retrospectively reviewed the data of 77 patients with SCC-L who received m-RADPLAT. Fourteen and 63 patients had creatinine clearance (CrCl) values of 30 ≤ CrCl < 60 mL/min and ≥60 mL/min, respectively. The m-RADPLAT regimen led to no significant changes in serum creatinine or CrCl values post-treatment. The 5-year local control, overall survival, and laryngectomy-free survival rates of the CrCl < 60 and ≥60 groups were 90.0% and 90.5%, 100% and 81.8%, and 100% and 79.0%, respectively. Grade 3 or higher toxicity rates were not significantly different between the groups. The m-RADPLAT regimen yielded favorable survival rates and clinical outcomes in patients with impaired renal function.

Standard or high dose chemoradiotherapy, with or without the protease inhibitor nelfinavir, in patients with locally advanced pancreatic cancer: The phase 1/randomised phase 2 SCALOP-2 trial

BackgroundThe multi-centre two-stage SCALOP-2 trial (ISRCTN50083238) assessed whether dose escalation of consolidative chemoradiotherapy (CRT) or concurrent sensitization using the protease inhibitor nelfinavir improve outcomes in locally advanced pancreatic cancer (LAPC) following four cycles of gemcitabine/nab-paclitaxel. MethodsIn stage 1, the maximum tolerated dose (MTD) of nelfinavir concurrent with standard-dose CRT (50.4 Gy in 28 fractions) was identified from a cohort of 27 patients. In stage 2, 159 patients were enrolled in an open-label randomized controlled comparison of standard versus high dose (60 Gy in 30 fractions) CRT, with or without nelfinavir at MTD. Primary outcomes following dose escalation and nelfinavir use were respectively overall survival (OS) and progression free survival (PFS). Secondary endpoints included health-related quality of life (HRQoL). ResultsHigh dose CRT did not improve OS (16.9 (60 % confidence interval, CI 16.2–17.7) vs. 15.6 (60 %CI 14.3–18.2) months; adjusted hazard ratio, HR 1.13 (60 %CI 0.91–1.40; p = 0.68)). Similarly, median PFS was not improved by nelfinavir (10.0 (60 %CI 9.9–10.2) vs. 11.1 (60 %CI 10.3–12.8) months; adjusted HR 1.71 (60 %CI 1.38–2.12; p = 0.98)). Local progression at 12 months was numerically lower with high-dose CRT than with standard dose CRT (n = 11/46 (23.9 %) vs. n = 15/45 (33.3 %)). Neither nelfinavir nor radiotherapy dose escalation impacted on treatment compliance or grade 3/4 adverse event rate. There were no sustained differences in HRQoL scores between treatment groups over 28 weeks post-treatment. ConclusionsDose-escalated CRT may improve local tumour control and is well tolerated when used as consolidative treatment in LAPC but does not impact OS. Nelfinavir use does not improve PFS.

Metabolic Profile of Cerebellum in Posterior Fossa Tumor Survivors: Correlation With Memory Impairment

AimsThe cerebellum is a key structure in working and procedural memory. The aim of the present prospective exploratory study was to investigate, the metabolic characteristics of the cerebellum in posterior fossa tumor (PFT) survivors using 3D proton magnetic resonance spectroscopy imaging (3D MRSI), to determine whether metabolites could be useful biomarkers of memory impairment. Materials and methodsSixty participants were included in the IMPALA study, divided into three groups: 22 irradiated PFT, 17 nonirradiated PFT, and 21 healthy controls matched with irradiated PFT for age, sex, and handedness. PFT survivors were treated at least 5 years ago, either by surgery or a combination of surgery, chemotherapy, and radiotherapy. All participants underwent working and procedural memory tests and multimodal MRI including a 3D MRSI sequence. N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and lactate (Lac) metabolite values were extracted from the cerebellum for comparisons between groups, correlations with neurocognitive test scores, and radiotherapy doses. ResultsMedian (range) age at neurocognitive tests was 18 (7–26) years. Median Cho, Cr, NAA, and Lac values, and the ratio of NAA to the sum of metabolites were significantly lower for PFT survivors than for healthy controls (p < 0.05). Scores on working and procedural memory tests were significantly lower for PFT survivors (p < 0.004) and correlated with median and maximum Cho and NAA values (0.28 <r < 0.49, p < 0.04). Except for creatine, the other metabolites were not significantly different between irradiated and nonirradiated survivors. MRSI values in the cerebellum were not correlated with either total dose or doses received by this structure. ConclusionResults revealed changes in cerebellar metabolic values in PFT survivors that were closely correlated with memory deficits, suggesting that some metabolites could be used as markers of cognitive decline, but this will require validation on a larger sample size.

A Prospective Randomised Comparative Study to Evaluate the Effect of Single Dose (6.25Gy Vs 8Gy) Palliative Radiotherapy with Zoledronic Acid in Patients with Painful Bone Metastases

Background: To assess the effectiveness of a single fraction dose of radiotherapy (6.25Gy versus 8 Gy) with zoledronic acid in cancer patients with painful bone metastases in treating pain; quality of life; duration of pain response and incidence of skeletal related events (SREs). Material and methods: A total of 80 patients with bone metastases presented in the department of Radiation Oncology, S.M.S hospital were randomly assigned to: Group A, received single dose of 6.25Gy with Zoledronic acid 4mg and Group B, received single dose of 8Gy with Zoledronic acid 4mg. The main variable was pain which was assessed with 11 point Numeric pain Rating Score (NRS). Results: There were total 80 patients, 40 in each group, with mean age 54.6 years and 54.5 years in group A and B respectively. Most frequent primary malignant sites were lung (36.2%), breast (28.7%), and prostate (8.7%). At 4 weeks post radiotherapy, complete response was 25% in group A, 27.5% in group B and overall response was 82.5% in group A, 85% in group B. At 2 months post radiotherapy complete response was observed in 25% of patients in group A, while 30% in group B and overall response in 85 % in group A and 87.5% in group B. Quality of life improved in both groups. Mean duration of pain relief was 13.5 weeks vs. 14.5 weeks respectively in group A and group B. Conclusion: There was improvement in pain relief and quality of life post radiotherapy in both the groups. On comparison between 2 groups, the overall pain relief was insignificant between the two dose schedules. So a lower dose 6.25Gy is almost as effective as 8 Gy single fractions for treatment of painful bone metastases.

Total management of hemangiopericytoma/solitary fibrous tumor of the buttock: A case report.

Solitary fibrous tumors can manifest at various anatomical sites, predominantly occurring at extrapleural sites with a peak incidence between 40 and 70 years. SFT necessitates long-term follow-up owing to its tumor characteristics. However, comprehensive reports covering the period from initial diagnosis to the patient's demise are lacking. Herein, we present a case of a malignant SFT of the buttocks that was treated at our hospital from the time of initial diagnosis to the end of life, with a literature review. A 54-year-old woman had a T1 low-to-isobaric and T2 isobaric-to-hyperintense mass in the psoas muscle on magnetic resonance imaging, diagnosed as an SFT. Wide excision was performed, followed by postoperative radiotherapy and chemotherapy. Multiple lung metastases were treated, while bone metastases appeared in the left femur. Multiple spinal metastases developed, causing respiratory distress due to pleural effusion. Best support care was initiated; however, a thrombus appeared in the inferior vena cava. Despite anticoagulant therapy, the patient died 11 years and 6 months after the initial surgery. Herein, marginal resection resulted in a relatively short operative time and average blood loss. The radiotherapy dose was 66 Gy; no complications occurred, and local recurrence was prevented. Tumor arthroplasty was performed to stabilize the affected limbs, and the patient required careful follow-up. Despite the poor prognosis, the patient survived >11 years after surgery and had a favorable outcome. Long-term monitoring for potential complications remains necessary.