Stereotactic body radiotherapy in pancreatic adenocarcinoma

Background:Stereotactic body radiotherapy(SBRT)in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding tissue.This review aimed at the SBRT application in the treatment of pancreatic cancer.Data sources:We retrieved articles published in MEDLINE/PubMed from January 2017 to December 2022.Keywords used in the search included:“pancreatic adenocarcinoma”OR“pancreatic cancer”AND“stereotactic ablative radiotherapy(SABR)”OR“stereotactic body radiotherapy(SBRT)”OR“chemoradiotherapy(CRT)”.English language articles with information on technical characteristics,doses and fractionation,indications,recurrence patterns,local control and toxicities of SBRT in pancreatic tumors were included.All articles were assessed for validity and relevant content.Results:Optimal doses and fractionation have not yet been defined.However,SBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to CRT.Furthermore,the combination of SBRT with chemotherapy may have additive or synergic effect on pancreatic adenocarcinoma.Conclusions:SBRT is an effective modality for patients with pancreatic cancer,supported by clinical practice guidelines as it has demonstrated good tolerance and good disease control.SBRT opens a possibility of improving outcomes for these patients,both in neoadjuvant treatment and with radical intent.

Present situation and prospect of immunotherapy for unresectable locally advanced esophageal cancer during peri-radiotherapy

Four major studies(Checkmate577,Keynote-590,Checkmate649 and Attraction-4)of locally advanced esophageal cancer published in 2020 have established the importance of immunotherapy,represented by anti-programmed death protein(PD)-1 in postoperative adjuvant treatment and advanced first-line treatment of locally advanced or advanced esophageal cancer and esophagogastric junction cancer,from the aspects of proof of concept,long-term survival,overall survival rate and progression-free survival.For unresectable or inoperable nonmetastatic esophageal cancer,concurrent radiotherapy and chemotherapy is the standard treatment recommended by various guidelines.Because its curative effect is still not ideal,it is necessary to explore radical radiotherapy and chemotherapy in the future,and it is considered to be promising to combine them with immunotherapeutic drugs such as anti-PD-1.This paper mainly discusses how to combine radical concurrent radiotherapy and chemotherapy with immunotherapy for unresectable local advanced esophageal cancer.

Radiotherapy for hyoid bone metastasis from lung adenocarcinoma:A case report

BACKGROUND Metastasis to the hyoid bone is an exceptionally rare occurrence,with documented cases limited to breast,liver,colon,skin,lung,and prostate cancers.This report highlights an unusual case involving the metastasis of lung adenocarcinoma to the hyoid bone,accompanied by a distinctive headache.Previous documentation involved surgical resection of the hyoid mass.We present a case displaying the benefits of palliative radiotherapy.CASE SUMMARY A 72-year-old non-smoking,non-alcoholic woman,initially under investigation for a year-long elevation in absolute lymphocyte count,presented with a monthlong history of intermittent throat pain.Despite negative findings in gastroenterological and otolaryngologic examinations,a contrast-enhanced chest computed tomography scan revealed a mediastinal mass and questionable soft tissue thickening in her left anterolateral neck.Subsequent imaging and biopsies confirmed the presence of lung adenocarcinoma metastasis to the hyoid bone.The patient was treated with platinum-based chemo-immunotherapy along with pembrolizumab.Ultimately,the lung cancer was unresponsive.Our patient opted for palliative radiation therapy instead of surgical resection to address her throat pain.As a result,her throat pain was alleviated,and it also incidentally resolved her chronic headaches.This is the second documented case of lung adenocarcinoma metastasizing to the hyoid bone.CONCLUSION Palliative radiotherapy may add to the quality of life in symptomatic patients with cancer metastatic to the hyoid bone.

Hemostatic radiotherapy for bleeding gastrointestinal

Hemostatic radiotherapy is a non-invasive treatment for bleeding gastrointestinal(GI)tumors,promoting tumor shrinkage,blood supply reduction,and fibrotic tissue formation.It is effective in cases where traditional interventions are insufficient or contraindicated and can prevent recurrent bleeding in patients with GI bleeding histories.Hypofractionation schedules are also effective for tumor control and patient compliance.

Signal intensity changes of dentate nucleus on plain MR T1WI innasopharyngeal carcinoma patients after radiotherapy andmultiple injections of gadolinium-base contrast agent

Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(ΔSI i),while the percentage of relative changes of year j(ranging from 2 to 5)was calculated withΔSI j compared toΔSI 1(Rchange j).The values of these two parameters were compared,and the correlation ofΔSI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age norΔSI 1 was found between groups(all P>0.05).The second to the fifth yearΔSI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P<0.05).Within both groups,ΔSI was positively correlated with GBCA injection year-time(both P<0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.

Targeting the organelle for radiosensitization in cancer radiotherapy

Radiotherapy is a well-established cytotoxic therapy for local solid cancers, utilizing high-energy ionizing radiation to destroy cancer cells. However, this method has several limitations, including low radiation energy deposition, severe damage to surrounding normal cells, and high tumor resistance to radiation. Among various radiotherapy methods, boron neutron capture therapy (BNCT) has emerged as a principal approach to improve the therapeutic ratio of malignancies and reduce lethality to surrounding normal tissue, but it remains deficient in terms of insufficient boron accumulation as well as short retention time, which limits the curative effect. Recently, a series of radiosensitizers that can selectively accumulate in specific organelles of cancer cells have been developed to precisely target radiotherapy, thereby reducing side effects of normal tissue damage, overcoming radioresistance, and improving radiosensitivity. In this review, we mainly focus on the field of nanomedicine-based cancer radiotherapy and discuss the organelle-targeted radiosensitizers, specifically including nucleus, mitochondria, endoplasmic reticulum and lysosomes. Furthermore, the organelle-targeted boron carriers used in BNCT are particularly presented. Through demonstrating recent developments in organelle-targeted radiosensitization, we hope to provide insight into the design of organelle-targeted radiosensitizers for clinical cancer treatment.

SENEX-mediated CDK4/6 inhibition promotes senescence and confers apoptosis resistance in B-cell non-Hodgkin lymphoma

Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a crucial mechanism contributing to tumor drug resistance.Here,we analyzed SENEX/Rho GTPase Activating Protein 18(ARHGAP18)expression and prognostic significance in doxorubicin-induced B-NHL-TIS model and r/r B-NHL patients,investigating its target in B-NHL cell senescence and the effect of combining specific inhibitors on apoptosis resistance in B-NHL-TIS cells.Methods:Raji cells were transfected with the human SENEX shRNA recombinant lentiviral vector(Sh-SENEX)and the empty vector negative(NC)to construct a stable transfection cell line with knockdown of SENEX.Effect of SENEX-silencing on B-NHL-TIS formation,cell function and cell cycle-related pathways was analyzed.Using doxorubicin(DOX)-inducible senescent B-NHL cells combined with the specific cyclin dependent kinase 4/6(CDK4/6)inhibitor Palbociclib to observe that blocking CDK4/6 effects on TIS formation.SENEX expression of 21 B-NHL patients and 8 healthy controls were analyzed by qRT-PCR,and the correlation between its expression and clinical indicators were evaluated.Results:The downregulation of SENEX expression promotes G1-S phase transition and apoptosis while inhibiting cell proliferation,collectively suppressing the formation of TIS in B-NHL.Blockade of CDK4/6 promotes the DOX-induced G1 phase arrest to enhance TIS formation in B-NHL cells which can reverse the regulatory effect of silencing SENEX on B-NHL cell cycle regulation and senescence.The expression levels of SENEX were notably elevated in B-NHL patients compared to healthy controls,and Elevated expression levels of SENEX were associated with poor prognosis of B-NHL patients.Conclusions:SENEX enhances apoptosis resistance in B-NHL by inhibiting CDK4/6,thereby preventing G1-S phase transition and promoting TIS formation.

Clinical study of chemotherapy-related cognitive impairment in patients with non-Hodgkin lymphoma

BACKGROUND Chemotherapy for malignant tumors can cause brain changes and cognitive impairment,leading to chemotherapy-induced cognitive impairment(CICI).Current research on CICI has focused on breast cancer and Hodgkin’s lymphoma.Whether patients with non-Hodgkin’s lymphoma(NHL)undergoing chemo-therapy have cognitive impairment has not been fully investigated.therapy have cognitive impairment has not been fully investigated.AIM To investigate whether NHL patients undergoing chemotherapy had cognitive impairments.METHODS The study included 100 NHL patients who were required to complete a compre-hensive psychological scale including the Brief Psychiatric Examination Scale(MMSE)at two time points:before chemotherapy and within 2 wk of two chemo-therapy courses.A language proficiency test(VFT),Symbol Number Pattern Test(SDMT),Clock Drawing Test(CDT),Abbreviated Daily Cognition Scale(ECog-12),Prospective and Retrospective Memory Questionnaire,and Karnofsky Perfor-mance Status were used to assess cognitive changes before and after chemo-therapy.RESULTS The VFT scores for before treatment(BT)and after treatment(AT)groups were 45.20±15.62,and 42.30±17.53,respectively(t-2.16,P<0.05).The CDT scores were 8(3.5-9.25)for BT and 7(2.5-9)for AT groups(Z-2.1,P<0.05).Retrospective memory scores were 13.5(9-17)for BT and 15(13-18)for AT(Z-3.7,P<0.01).The prospective memory scores were 12.63±3.61 for BT and 14.43±4.32 for AT groups(t-4.97,P<0.01).The ECog-12 scores were 1.71(1.25-2.08)for BT and 1.79(1.42-2.08)for AT groups(Z-2.84,P<0.01).The SDMT and MMSE values did not show a significant difference between BT and AT groups.CONCLUSION Compared to the AT group,the BT group showed impaired language,memory,and subjective cognition,but objec-tive cognition and execution were not significantly affected.

Enhancing Precision in Radiotherapy Delivery: Validating Monte Carlo Simulation Models for 6 MV Elekta Synergy Agility LINAC Photon Beam Using Two Models of the GAMOS Code

The most crucial requirement in radiation therapy treatment planning is a fast and accurate treatment planning system that minimizes damage to healthy tissues surrounding cancer cells. The use of Monte Carlo toolkits has become indispensable for research aimed at precisely determining the dose in radiotherapy. Among the numerous algorithms developed in recent years, the GAMOS code, which utilizes the Geant4 toolkit for Monte Carlo simula-tions, incorporates various electromagnetic physics models and multiple scattering models for simulating particle interactions with matter. This makes it a valuable tool for dose calculations in medical applications and throughout the patient’s volume. The aim of this present work aims to vali-date the GAMOS code for the simulation of a 6 MV photon-beam output from the Elekta Synergy Agility linear accelerator. The simulation involves mod-eling the major components of the accelerator head and the interactions of the radiation beam with a homogeneous water phantom and particle information was collected following the modeling of the phase space. This space was po-sitioned under the X and Y jaws, utilizing three electromagnetic physics mod-els of the GAMOS code: Standard, Penelope, and Low-Energy, along with three multiple scattering models: Goudsmit-Saunderson, Urban, and Wentzel-VI. The obtained phase space file was used as a particle source to simulate dose distributions (depth-dose and dose profile) for field sizes of 5 × 5 cm2 and 10 × 10 cm2 at depths of 10 cm and 20 cm in a water phantom, with a source-surface distance (SSD) of 90 cm from the target. We compared the three electromagnetic physics models and the three multiple scattering mod-els of the GAMOS code to experimental results. Validation of our results was performed using the gamma index, with an acceptability criterion of 3% for the dose difference (DD) and 3 mm for the distance-to-agreement (DTA). We achieved agreements of 94% and 96%, respectively, between simulation and experimentation for the three electromagnetic physics models and three mul-tiple scattering models, for field sizes of 5 × 5 cm2 and 10 × 10 cm2 for depth-dose curves. For dose profile curves, a good agreement of 100% was found between simulation and experimentation for the three electromagnetic physics models, as well as for the three multiple scattering models for a field size of 5 × 5 cm2 at 10 cm and 20 cm depths. For a field size of 10 × 10 cm2, the Penelope model dominated with 98% for 10 cm, along with the three multiple scattering models. The Penelope model and the Standard model, along with the three multiple scattering models, dominated with 100% for 20 cm. Our study, which compared these different GAMOS code models, can be crucial for enhancing the accuracy and quality of radiotherapy, contributing to more effective patient treatment. Our research compares various electro-magnetic physics models and multiple scattering models with experimental measurements, enabling us to choose the models that produce the most reli-able results, thereby directly impacting the quality of simulations. This en-hances confidence in using these models for treatment planning. Our re-search consistently contributes to the progress of Monte Carlo simulation techniques in radiation therapy, enriching the scientific literature.

Evaluation of Air-Kerma and Absorbed Dose to Water for External Radiotherapy Beam Using Ionization Chamber

Radiotherapy is the most widely applied oncologic treatment modality utilizing ionizing radiation. A high degree of accuracy, reliability and reproducibility is required for a successful treatment outcome. Measurement using ionization chamber is a prerequisite for absorbed dose determination for external beam radiotherapy. Calibration coefficient is expressed in terms of air kerma and absorbed dose to water traceable to Secondary Standards Dosimetry Laboratory. The objective of this work was to evaluate the level of accuracy of ionization chamber used for clinical radiotherapy beam determination. Measurement and accuracy determination were carried out according to IAEA TRS 398 protocol. Clinical farmers type ionization chamber measurement and National Reference standard from Secondary Standards Dosimetry Laboratory were both exposed to cobalt-60 beam and measurement results compared under the same environmental conditions. The accuracy level between National Reference Standard and clinical radiotherapy standard was found to be −1.92% and −2.02% for air kerma and absorbed dose to water respectively. To minimize the effect of error and maximize therapeutic dose during treatment in order to achieve required clinical outcome, calibration factor was determined for air kerma (Nk) as 49.7 mGy/nC and absorbed dose to water ND, as 52.9 mGy/nC. The study established that radiotherapy beam measurement chain is prone to errors. Hence there is a need to independently verify the accuracy of radiation dose to ensure precision of dose delivery. The errors must be accounted for during clinical planning by factoring in calibration factor to minimize the systematic errors during treatment, and thereby providing enough room to achieve ±5% dose delivery to tumor target as recommended by ICRU.

Efficacy and Safety of Primary Radiotherapy in Combination with EGFR-TKIs for Non-Small Cell Lung Cancer Harboring EGFR Mutation

Objective: To evaluate the efficacy and safety of EGFR-TKI with the radiotherapy in EGFR mutant metastatic NSCLC. Methods: Retrospective analysis of 72 patients with stage IV lung cancer with EGFR-sensitive mutation. Patients in the A group were treated with the first-generation EGFR-TKI (Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor) combined with radiotherapy for primary tumors (34 cases). The B group was treated with the first-generation EGFR-TKI alone until the disease progressed (38 cases). PFS, OS, pulmonary infection and hematological toxicity during treatment were commented in both groups. Results: The objective remission rate was 47.1% (16/34) in the A group and 21.1% (8/38) in the B group. There was a significant difference between the two groups. There was no significant difference in hematological toxicity between the A group and the B group. There were 10 patients (29.4%) with degree II pulmonary infection in the A group and 3 patients (7.9%) in the B group. The difference between the two groups was statistically significant, suggesting that the incidence of pneumonia in the A group was higher than that in the B group. The median PFS (Progression-Free Survival)) and OS (Overall Survival) of the A group were significantly longer than those of the B group (16.5 months vs 9 months) and the median OS (36 months vs 19 months). The PFS and OS in the A group were significantly longer than those in the B group. Conclusion: EGFR-TKI combined with primary radiotherapy can significantly prolong the drug resistance time of EGFR mutant metastatic NSCLC.

Chemotherapy and radiotherapy:Could they contribute to the development of new tumors and metastases?

Objective: Both chemotherapy and radiotherapy have demonstrated high effectiveness as the best mechanisms in the fight against cancer;however, various studies seem to confirm that they could also favor the development of other unwanted effects of great importance for the patient. The main objective of this study is to find out the possible existence of this type of links. Method: This is a systematic literature review that seeks to find out which and how long cases of late interactions related to chemotherapy and radiotherapy treatments have been known. The bibliographic review was carried out based on references published in the last five years. Results: Various studies confirm the possible relationship between chemotherapy and radiotherapy treatments with the development of new undesirable side effects, especially as a consequence of the hepatotoxicity generated in the case of chemotherapy and radiation in radiotherapy. However, in this last type of treatment, the problems raised are really few. Conclusions: The existence of a risk of suffering new unwanted side effects after different types of treatment seems to have been demonstrated, especially in the case of chemotherapy. In the case of radiotherapy, adverse effects are practically non-existent, although they are no less important.

Primary Non-Hodgkin’s Malignant Lymphoma of the Uterus at the Reference Hospital of Maradi/Niger: A Case Report

Malignant non-Hodgkins lymphoma (MHNL) of the uterus is uncommon. We report a case diagnosed on the basis of histologic and immunohistochemical studies of a hysterectomy specimen induced by a very painful pelvic mass in a 50-year-old patient with no previous history of the disease. It was classified as Ann Arbor IV Bb after imaging, given the medullary infiltration and signs of clinical and biological evolutivity: the patient had received two courses of chemotherapy, CHOP protocol. She died 23 days after the second treatment due to a hypertensive crisis.

Correlation between dose-volume parameters and rectal bleeding after 12 fractions of carbon ion radiotherapy for prostate cancer

BACKGROUND Carbon ion radiotherapy(CIRT)is currently used to treat prostate cancer.Rectal bleeding is a major cause of toxicity even with CIRT.However,to date,a correlation between the dose and volume parameters of the 12 fractions of CIRT for prostate cancer and rectal bleeding has not been shown.Similarly,the clinical risk factors for rectal bleeding were absent after 12 fractions of CIRT.AIM To identify the risk factors for rectal bleeding in 12 fractions of CIRT for prostate cancer.METHODS Among 259 patients who received 51.6 Gy[relative biological effectiveness(RBE)],in 12 fractions of CIRT,15 had grade 1(5.8%)and nine had grade 2 rectal bleeding(3.5%).The dose-volume parameters included the volume(cc)of the rectum irradiated with at least x Gy(RBE)(Vx)and the minimum dose in the most irradiated x cc normal rectal volume(Dx).RESULTS The mean values of D6cc,D2cc,V10 Gy(RBE),V20 Gy(RBE),V30 Gy(RBE),and V40 Gy(RBE)were significantly higher in the patients with rectal bleeding than in those without.The cutoff values were D6cc=34.34 Gy(RBE),D2cc=46.46 Gy(RBE),V10 Gy(RBE)=9.85 cc,V20 Gy(RBE)=7.00 cc,V30 Gy(RBE)=6.91 cc,and V40 Gy(RBE)=4.26 cc.The D2cc,V10 Gy(RBE),and V20 Gy(RBE)cutoff values were significant predictors of grade 2 rectal bleeding.CONCLUSION The above dose-volume parameters may serve as guidelines for preventing rectal bleeding after 12 fractions of CIRT for prostate cancer.

Changes in acute and late toxicity and patient-reported health-related quality of life following radiotherapy in women with breast cancer:A 1-year longitudinal study

Objective:The objective of this study was to investigate the frequency of acute and late toxicities,as well as changes in the quality of life(QOL)for breast cancer patients following radiotherapy(RT).Materials and Methods:A total of 108 breast cancer women were recruited for this prospective study.Data were collected at various intervals;prior to,and 1,3,6 months,and 1 year after radiation therapy.The primary outcomes were toxicity radiation therapy oncology group/European Organization for Research and Treatment of Cancer(EORTC)criteria.Our secondary outcome was QOL,measured using EORTC QLQ-C30 and Edmonton Symptom Assessment Scale.We employed Friedman’s two-way analysis to evaluate the changes in QOL over the course of 1 year.Results:The early toxicities that are most commonly experienced include pharyngeal,skin,and mucous membrane toxicity.Late toxicities frequently involve skin and submucosal toxicity.To measure patient functionality,all functional subscale scores except for the patient’s emotional state increased over time compared to pre-RT.Symptoms of the patients,which were included in the QOL symptom scale,decreased during the follow-up period,except for fatigue;however,changes in pain,insomnia,and loss of appetite did not significantly change.We identified the analogous symptom profiles in Edmonton.Although patients’overall health scores declined in the 1st and 3rd months after radiotherapy(RT),they rebounded at 6 and 12 months.Conclusion:For breast cancer patients,RT did not adversely affect functional capacity or exacerbate symptoms,but persistent fatigue did increase during the observation period.Health-care professionals ought to devise strategies to assist patients with skin toxicity and fatigue.

Pneumocystis pneumonia in stage IIIA lung adenocarcinoma with immune-related acute kidney injury and thoracic radiotherapy:A case report

BACKGROUND Immune checkpoint inhibitors(ICIs)are therapeutic agents for advanced and metastatic non-small cell lung cancer(NSCLC)with high clinical antitumor efficacy.However,immune-related adverse events occur in 20%of these patients and often requiring treatment with immunosuppressive agents,such as corticosteroids.Consequently,this may increase the risk of patients to opportunistic infections.Pneumocystis jirovecii pneumonia(PJP),a rare but serious opportunistic infection typically observed in patients with human immunodeficiency virus,can also occur in cancer patients undergoing long-term glucocorticoid treatment.CASE SUMMARY We report a case of a 56-year-old male with squamous NSCLC treated with triplimab combined with paclitaxel,carboplatin,and radical thoracic radiation therapy.Following this regimen,he developed acute kidney injury(AKI)with elevated creatinine levels.After concurrent radical chemoradiotherapy ended,he developed a grade 3 immune-related AKI.High-dose corticosteroids were administered to treat AKI,and renal function gradually recovered.Corticosteroids were reduced to a dose of 10 mg prednisone equivalent daily eight weeks later;however,he developed severe pneumonia with spontaneous pneumothorax.Next-generation sequencing of the bronchoscopic lavage revealed PJP co-infection with herpes simplex virus 1 and cytomegalovirus.The inflammation was more severe in areas exposed to radiation.Piperacillin-tazobactam,acyclovir,sulfamethoxazole,and trimethoprim were used to control the infection.The patient recovered,and immunotherapy was terminated.CONCLUSION PJP is rare but can occur in patients with ICI adverse events and should be differentiated from tumor progression or immune-related adverse events.Thoracic radiation may increase risk,necessitating careful monitoring and prevention.

Assessment of Occupational Radiation Exposure for Radiotherapy Healthcare Workers at Kenyatta National Hospital Using Thermoluminescence Dosimeter LiF:Mg,Ti

Kenyatta National Hospital (KNH) is the largest public referral hospital with a comprehensive cancer treatment facility in East and Central Africa. Occupational radiation monitoring is a significant technique for demonstrating compliance of radiation regulatory limits. The objective of the study was to carry out assessment of occupational radiation exposure among radiotherapy personnel at KNH using thermoluminescence dosimeter, TLD. KNH staff were monitored using dosimeter type TLD-100 made of LiF:Mg,Ti, on monthly basis. The reader system used for analysis was Harshaw 8800. The measurement established the average monthly accumulated occupational personnel dose for KNH to be 0.21 mSv and 0.29 mSv for Hp (10) and Hp (0.07) respectively. The accumulated dose results were within the maximum acceptable dose of 1.67 mSv/month and 41.6 mSv/month for Hp (10) and Hp (0.07) respectively. The investigation results were higher than the acceptable public limit of 0.08 mSv/month. Moreover, incidences were noted where the fetus dose limit 0.42 was also exceeded. Evaluation of statistical dose exposure among doctors, nurses and radiographers’ measurement results were within ±0.02 mSv. The study established the average KNH occupational radiation exposure levels for both Hp (10) and Hp (0.07) were within the ICRU recommendation, validating radiation protection safe practice. Data analysis of healthcare workers did not indicate exposure trend biased to any healthcare profession. Hence radiation risk cut across all professional categories. It is recommended that Radiation Monitoring program be reviewed to include non-clinical staff who access the facility. Radiation reporting should not be limited to one facility, but reflect cases where workers are involved in multiple multiple jobs.

Radical radiotherapy without surgical tumor resection for rectal cancer

In this editorial,I would like to comment on the article,recently published in the World Journal of Clinical Oncology.The article focuses on non-surgical treatments for locally recurrent rectal cancer,including the watch-and-wait(WW)strategy after total neoadjuvant therapy(TNT)and particle beam therapy.As treatment options for rectal cancer continue to evolve,the high complete response rate achieved with TNT has led to the development of a new non-surgical approach:WW.Chemoradiotherapy followed by consolidation chemotherapy,in particular,has a low rate of tumor growth and is a treatment aimed at achieving a cure without surgery.However,the risk of recurrence within two years is significant,necessitating careful follow-up.Establishing standardized follow-up methods that can be implemented by many physicians is essential.Carbon ion radiotherapy has demonstrated high local control with a low incidence of severe late toxicities,even after previous pelvic radiotherapy.While these new non-surgical curative treatments for rectal cancer require further investigation,future advancements in this field are anticipated.

Evaluation of Dosimetric Impact of Uncertainty of Measurement in Estimating External Radiotherapy Dose

Cancer is a major societal public health and economic problem, responsible for one in every six deaths. Radiotherapy is the main technique of treatment for more than half of cancer patients. To achieve a successful outcome, the radiation dose must be delivered accurately and precisely to the tumor, within ± 5% accuracy. Smaller uncertainties are required for better treatment outcome. The objective of the study is to investigate the uncertainty of measurement of external radiotherapy beam using a standard ionization chamber under reference conditions. Clinical farmers type ionization chamber measurement was compared against the National Reference standard, by exposing it in a beam 60Co gamma source. The measurement set up was carried out according to IAEA TRS 498 protocol and uncertainty of measurement evaluated according to GUM TEDDOC-1585. Evaluation and analysis were done for the identified subjects of uncertainty contributors. The expanded uncertainty associated with 56 mGy/nC ND,W was found to be 0.9% corresponding to a confidence level of approximately 95% with a coverage factor of k = 2. The study established the impact of dosimetry uncertainty of measurement in estimating external radiotherapy dose. The investigation established that the largest contributor of uncertainty is the stability of the ionization chamber at 36%, followed by temperature at 22% and positioning of the chamber in the beam at 8%. The effect of pressure, electrometer, resolution, and reproducibility were found to be minimal to the overall uncertainty. The study indicate that there is no flawless measurement, as there are many prospective sources of variation. Measurement results have component of unreliability and should be regarded as best estimates of the true value. .

Study on the Impact of Post-Mastectomy Radiotherapy on Immediate Breast Reconstruction and Complications: A Meta-Analysis

Background and objective:Immediate breast reconstruction not only reduces the number of surgeries for patients after mastectomy but also decreases psychological and physical trauma,making it increasingly popular.However,there is currently no consensus on the integration of post-mastectomy radiotherapy(PMRT)with reconstruction techniques.This review evaluates the impact of PMRT on complications following immediate breast reconstruction,providing guidance for clinical treatment decisions.Methods:PubMed,Web of Science,Embase,and other databases were searched for studies published in the past 15 years on outcomes of implant-based breast reconstruction in the context of radiotherapy to identify articles for analysis.RevMan 5.4 software was used to analyze the risks of seroma,infection,wound dehiscence,flap necrosis,implant exposure,capsule contracture,and reconstruction failure.Results:A total of 1l relevant studies were included,comprising 6323 cases of immediate breast reconstruction.It was found that breasts receiving postoperative irradiation had a significantly increased risk of complications,with statistically significant differences in seroma(P=0.004),infection(P<0.00001),wound dehiscence(P=0.04),implant exposure(P<0.00001),capsule contracture(P<0.00001),and reconstruction failure(P<0.00001).There was no statistically significant difference in flap necrosis(P=0.88).Conclusion:The results indicate that postoperative radiotherapy significantly increases the risk of complications for patients undergoing immediate implant-based reconstruction.Preventive measures may be taken in advance with the assistance of healthcare providers if necessary.