Microbiome and Abdominopelvic Radiotherapy Related Chronic Enteritis: A Microbiome-based Mechanistic Role of Probiotics and Antibiotics.

Chronic diarrhea and abdominal pain after radiotherapy continue to be a problem in cancer survivors. Gut microbiomes are essential for preventing intestinal inflammation, maintaining intestinal integrity, maintaining enterohepatic circulation, regulating bile acid metabolism, and absorption of nutrients, including fat-soluble vitamins. Gut microbiome dysbiosis is expected to cause inflammation, bile acid malabsorption, malnutrition, and associated symptoms. Postradiotherapy, Firmicutes and Bacteroidetes phylum are significantly decreased while Fusobacteria and other unclassified bacteria are increased. Available evidence suggests harmful bacteria Veillonella, Erysipelotrichaceae, and Ruminococcus are sensitive to Metronidazole or Ciprofloxacin. Beneficial bacteria lactobacillus and Bifidobacterium are relatively resistant to metronidazole. We hypothesize and provide an evidence-based review that short-course targeted antibiotics followed by specific probiotics may lead to alleviation of radiation enteritis.

Is FAST FORWARD the Way Forward in Radiotherapy for Locally Advanced Breast Cancer - Learnings From the COVID Pandemic.

INTRODUCTION: Low middle-income countries (LMICs), including India, have paucity of external beam radiotherapy (RT) machines leading to prolonged wait times for RT. Delay in delivery of RT has been shown to adversely affect outcomes in locally advanced breast cancer (LABC). With the availability of results of multiple randomized controlled trials, hypofractionated RT delivered over 3 to 4 weeks became the standard of care in breast cancer RT. METHODS: We conducted a retrospective audit of 172 LABC patients treated with ultrahypofractionated adjuvant RT (radiotherapy completed in 1 week) during the COVID pandemic. Log rank and Cox-regression model used for univariate and multi-variate analyses. RESULTS: No patient developed grade 3 esophagitis. Grade 2 esophagitis requiring short term narcotic analgesics was seen in 12 (6.9%) patients. Grade 2 or higher toxicity peaked between 2 and 3 weeks after RT. The estimated 2 and 3- year recurrence free survival (RFS) for the cohort is 87.1 % and 81.4 %, respectively. The estimated 2 and 3-year overall survival for the cohort is 95% and 91.3%. On multivariate analysis, presence of extra-nodal extension was found to be an independent factor associated with worse RFS (P = .028). CONCLUSIONS: FAST FORWARD protocol RT in LABC appears well tolerated.

Lymphocyte sparing normal tissue effects in the clinic (LymphoTEC): A systematic review of dose constraint considerations to mitigate radiation-related lymphopenia in the era of immunotherapy.

BACKGROUND: Radiation-related lymphopenia has been associated with suboptimal tumor control rates leading to inferior survival outcomes. To date, no standardized dose constraints are available to limit radiation dose to resident and circulating lymphocyte populations. We undertook this systemic review of the literature to provide a synopsis of the dosimetric predictors of radiation-related lymphopenia in solid malignancies. METHODOLOGY: A systematic literature review of PubMed (National Institutes of Health), Cochrane Central (Cochrane collaboration), and Google Scholar was conducted with the following keywords: "radiation", "lymphopenia", "cancer", "dosimetric predictors" with an inclusion deadline of May 31, 2022. Studies that met prespecified inclusion criteria were designated either Good, Fair, or Poor Quality based on the Newcastle-Ottawa quality assessment. The dosimetric parameters derived from Good Quality studies were tabulated as LymphoTEC dose constraints. Dosimetric parameters derived from Fair and Poor-quality studies were grouped as optional. RESULTS: An initial systematic search of the literature yielded 1,632 articles. After screening, a total of 48 studies met inclusion criteria and were divided into the following categories: central nervous system (CNS, 6), thoracic (11), gastrointestinal (26), gynecologic (2), head and neck, breast, and genitourinary (one each) cancers. Lung mean dose, heart mean dose, brain V25, spleen mean dose, estimated dose to immune cells, and bone marrow V10 were among the strongest predictors for severe lymphopenia related to radiotherapy. CONCLUSION: Optimizing the delivery of radiation therapy to limit dose to lymphocyte-rich structures may curb the negative oncologic impact of lymphocyte depletion. The dose constraints described herein may be considered for prospective validation and future use in clinical trials to limit risk of radiation-related lymphopenia and possibly improve cancer-associated outcomes.

Demography, patterns of care, and survival outcomes in patients with salivary duct carcinoma: an individual patient data analysis of 857 patients.

Aim: Salivary duct carcinoma (SDC) is a rare and aggressive malignancy. The optimal treatment protocols are debated. Methodology: A systematic search and individual patient data analysis of published cases of SDC was performed. SPSS v21 was used for statistical analysis. Results: Data of 857 patients available. Median overall survival (OS) and progression-free survival (PFS) of the entire cohort 42 months and 24 months. Nodal involvement, males, primary size >5 cm, androgen receptor (AR) negativity significantly worse OS. Patients with surgery had a favorable median PFS (p = 0.000) and OS (p = 0.077). Patients with adjuvant radiation had better PFS (30 vs 18 months; p = 0.077). Conclusion: SDC has modest survival. Surgery and adjuvant radiation should be advocated for all patients. AR expression appears prognostic for survival.

Rosette Forming Glioneural Tumor Treated with Conformal Radiation.

Rosette forming glioneural tumors (RGNT) are a rare type of low-grade brain tumor included in 2007 in WHO classification. Given the benign nature of the disease, a complete surgical excision has been considered optimum. However, a handful of cases have reported the locally aggressive nature of RGNT. In addition, radiation may also be considered for a tumor located in areas where surgical excision is difficult. We present a similar case, where surgical risk was weighed against resection and we treated the patient with conformal radiation.

A systematic review and meta-analysis of the impact of radiation-related lymphopenia on outcomes in pancreatic cancer.

Background: Pancreatic cancer is a devastating disease with a 5-year survival rate of 5-10%. Radiation is commonly used in neoadjuvant and adjuvant settings to improve local control. Studies have shown that circulating lymphocyte count depletion after radiation has been associated with poor tumor control and inferior overall survival (OS) outcomes. Method: To better understand the impact of radiation-associated lymphopenia in pancreatic cancer, the authors undertook this systematic review and meta-analysis of clinical studies that have reported radiation-related lymphopenia in pancreatic cancer. Results: A systematic methodology search of PubMed, Embase and the Cochrane Library resulted in 2969 abstracts. Nine studies fulfilled the inclusion criteria. Six studies reported on outcomes in patients undergoing definitive chemoradiation and three studies comparing outcomes in stereotactic body radiotherapy versus definitive chemoradiation. The patients with severe lymphopenia were at increased risk of death with a pooled hazard ratio of 2.33 (95% CI: 1.79, 3.03; I2: 36%; p < 0.001) compared with patients with no severe lymphopenia. The odds of developing severe lymphopenia were 1.12 (95% CI: 0.45, 2.79; I2: 95%; p < 0.81). The pooled mean difference for OS was -6.80 months (95% CI: -10.35, -3.24; I2: 99%; p < 0.002), suggesting that patients who develop grade 3 or 4 lymphopenia have inferior median OS outcomes. Limiting the mean splenic dose to less than 9 Gy as well as various spleen dosimetric parameters such as visit (V)10 <32%, V15 <23% and V20 <15.4% can reduce the incidence of severe lymphopenia. Conclusion: Radiation-related lymphopenia is associated with an increased hazard of death and inferior median OS. Spleen dosimetric parameters correlate with the incidence of severe lymphopenia and with sub-optimal survival outcomes. There is a need to validate these findings in prospective studies.

A Systematic Review and Meta-analysis of the Impact of Radiation-Related Lymphopenia on Outcomes in High-Grade Gliomas.

Supriya MallickIntroduction Malignant gliomas are the most common primary malignant brain tumors and are typically treated with maximal safe surgical resection followed by chemoradiation. One of the unintended effects of radiation is depletion of circulating lymphocyte pool, which has been correlated with inferior overall survival outcomes. Methods A comprehensive and systematic searches of the PubMed, Cochrane Central, and Embase databases were done to assess the studies that have reported radiation-related lymphopenia in high-grade gliomas. Hazard ratios (HRs), odds ratios (OR), and mean differences were represented with Forest plots comparing patients with severe lymphopenia and no severe lymphopenia. Review Manager Version 5.3 (The Nordic Cochrane Centre, Copenhagen, Denmark) was used for the analysis. Results Nineteen studies were included in the final systematic review and 12 studies were included in the meta-analysis. The odds of developing severe lymphopenia were 0.39 (95% CI:0.19, 0.81, I 2 = 94%, p = 0.01). Patients with severe lymphopenia were at increased risk of death with a pooled HR = 2.19 (95% CI: 1.70, 2.83, I 2 = 0%, p <0.00001) compared to patients with no severe lymphopenia. The mean difference in survival between patients with severe lymphopenia and no severe lymphopenia was -6.72 months (95% CI: -8.95, -4.49, I 2 = 99%, p <0.00001), with a better mean survival in the no severe lymphopenia group. Conclusion Radiation-induced severe lymphopenia was associated with poor overall survival and increased risk of death. Photon therapy, larger planning target volume, higher brain dose, higher hypothalamus dose, and female gender were associated with increased risk of severe lymphopenia.

A Systematic Review of Radiation-Related Lymphopenia in Genito-urinary Malignancies.

BACKGROUND: The impact of radiation-related lymphopenia on clinical outcomes has been reported in various solid malignancies such as high grade gliomas, head and neck cancers, thoracic malignancies and gastro-intestinal malignancies but its impact is not clearly known in the context of common genito-urinary (GU) malignancies. METHODOLOGY: To better understand the effect of radiation-associated lymphopenia in prostate and bladder cancer, we undertook this systematic review of clinical studies that have studied radiation-related lymphopenia in GU malignancies. A systematic methodology search of PubMed, Embase, and Cochrane library resulted in 2125 abstracts. Ten studies fulfilled the inclusion criteria which included any prospective, retrospective study or cohort study of prostate, urinary bladder, kidney, ureter, urethra, penile cancer in humans, and radiation should be part of treatment and intent has to be in definitive or adjuvant settings. Finally the study should have data on radiation-related lymphopenia. RESULTS: Four studies reported on the cancer-specific outcomes related to the lymphopenia. The incidence of low lymphocyte counts were documented in all the studies. Three studies analyzed the factors associated with the Lymphocyte depletion. Pooled incidence of severe lymphopenia was 29.25% and mild to moderate lymphopenia was 60.75%. Bone marrow volume receiving 40 Gy was associated with the incidence of lymphopenia. CONCLUSION: One-third of the patients suffer from severe lymphopenia after radiation in prostate and bladder cancer. There are no clear data to support the correlation between severe lymphopenia and disease outcomes. Bone marrow dosimetry can affect the incidence and severity of lymphopenia. There is need of prospective datasets to identify the impact of radiation-related lymphopenia in GU malignancies focusing on long-term side effects, recurrence rates, and overall survival.

Risk and impact of radiation related lymphopenia in lung cancer: A systematic review and meta-analysis.

BACKGROUND: Despite the modern advances in treatment techniques, the survival of locally advanced lung cancer patients continues to remain poor. Circulating lymphocytes have an important role to play in local immune response to RT as well as immune checkpoint inhibitors, and radiation related lymphopenia has been associated with inferior survival in various tumors. METHODS: We undertook this systematic review and meta-analysis to evaluate the literature on risk and impact of lymphopenia in thoracic tumors. A systematic methodology search of the PubMed, Embase and Cochrane library was performed and eligible studies selected based on pre-defined inclusion and exclusion criteria. Review Manager Version 5.4.1 was used for the meta-analysis. RESULTS: Fourteen studies were included in the final systematic review and 10 in the quantitative analysis. Overall mean incidence of severe lymphopenia (absolute lymphocyte count < 500) was 64.24%. The patients with severe lymphopenia were at increased risk of death with a pooled HR of 1.59 (95% CI: 1.40, 1.81, I2 = 17%, P < 0.001) and progression with a pooled HR of 2.1 (95% CI: 1.57, 2.81, I2 = 59%, P < 0.001) compared to patients with no severe lymphopenia. Dosimetric parameters including gross tumor volume, lung V5 and heart V5 were predictive of lymphopenia, while advanced age, lower baseline lymphocyte counts, higher stage and large tumor size were other risk factors. Models predicting estimated radiation dose to lymphocytes were a good surrogate for treatment outcomes. CONCLUSION: Radiation related lymphopenia is associated with increased hazard of progression and death in lung cancer. Minimizing the lung and heart dose, especially in patients with concurrent other risk factors can reduce lymphopenia and potentially improve treatment outcomes in these patients.

Laryngeal soft tissue sarcoma: Systematic review and individual patient data analysis of 300 cases.

BACKGROUND: Laryngeal sarcoma is rare. We performed a systematic review and individual patient analysis to evaluate the patterns of care, prognostic factors, and role of radiotherapy in laryngeal soft tissue sarcoma. METHODS: A systematic search on PubMed and Google scholar was done. An individual patient data analysis was done. RESULTS: Of the 300 cases of laryngeal sarcoma, 80% underwent surgery. 44% underwent larynx preservation surgery and 25% received radiotherapy with surgery. Median progression free survival (PFS) was 48 months and overall survival (OS) of 224 months for the entire cohort. Patients with large primary, cartilage invasion, and positive margins had numerically worse PFS. Cartilage invasion and primary tumor size >3 cm were the most common risk factors for adjuvant radiation therapy. Patients receiving radiotherapy were not associated with better survival. CONCLUSION: Laryngeal sarcoma associated with a good survival. Larynx preservation surgery is feasible in nearly half patients. Adjuvant radiotherapy may be warranted in patients poor prognostic factors.

Tectal Rosette-Forming Glioneuronal Tumor - A Case Report Focusing on a Possible Role for Radiotherapy in Inoperable Tumors.

BACKGROUND: Rosette-forming glioneuronal tumor (RGNT) is a rare and distinctive glioneuronal tumor. Although surgical excision is considered the standard treatment for these slow growing WHO Grade I tumors, gross-total resection is achieved in less than 50% of RGNTs due to its localisation amidst vital structures. With very few cases with long term follow-up reported, there is limited knowledge of the natural clinical course and the role of radiotherapy in inoperable RGNTs. CASE DESCRIPTION: A previously well 26-year old male, presented with long standing headache, increasing gait instability and fainting episodes. Imaging revealed a tectal plate mass with hydrocephalous. An endoscopic third ventriculostomy and biopsy was done, revealing RGNT. He received radiotherapy with a curative intent. The patient remained neurologically stable for 4 years. Follow-up imaging done after 4 years showed decrease in tumor size. CONCLUSIONS: The current case highlights a role for radiotherapy in RGNTs occurring in surgically challenging sites.

The mechanistic rationale of drugs, primary endpoints, geographical distribution of clinical trials against severe acute respiratory syndrome-related coronavirus-2: A systematic review.

There are numerous ongoing studies assessing treatment options for preventing, treating, and managing complications of coronavirus disease-2019 disease. The objective of this study was to do a systematic review and critical appraisal of the ongoing clinical trials with an aim to provide insight into the various interventions tested, clinical rationale, geographical distribution of the trials as well as the endpoints assessed in the studies. ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, and PubMed were assessed till 11 May 2020. The search resulted in 3242 ongoing studies of which 829 studies were included. There are 134 different drug-based interventions being assessed in 463 clinical trials as treatment options China accounts for 35% of all ongoing clinical studies followed by USA 23% and other countries together account for 42%. Amongst the 463 studies assessing drug-based treatment options, studies that are funded by federal and academic institutions are 79.6%, pharmaceutical company-funded studies are 15.11%, and no funding information is available in 5.10%. The definitive outcomes like mortality are being assessed as primary outcome in 22.8% of the studies only and need for ventilator in 6.2% of the studies. Amongst the pharmaceutical company-funded drug-based studies, only 20% of the studies had mortality as the primary outcome. Only 5.5% of the ongoing clinical trials are specifically designed to assess the most vulnerable population like elderly, patients with comorbidities and cancer. Multiple intervention-based clinical studies against severe acute respiratory syndrome-related coronavirus-2 are being performed throughout the world with a high concentration of clinical trials in the developed world with concern that of elderly and patients with comorbidities are being underrepresented and definite endpoints like mortality are being assessed in only one-fifth of the studies.

A phase III randomised trial of trans-abdominal ultrasound in improving application quality and dosimetry of intra-cavitary brachytherapy in locally advanced cervical cancer.

INTRODUCTION: Intra-cavitary brachytherapy (ICB) remains an integral part of radiotherapy treatment in cervical cancer. Two-dimensional X ray point-based planning remains common and blind insertion leads to uterine perforations and higher toxicity. We conducted a randomised controlled trial of using trans-abdominal ultrasound in performing ICB to reduce perforation and organ at risk doses. PATIENT AND METHODS: The present study is a phase III open label randomised controlled trial of ultrasound guided ICB conducted on invasive cervical cancer patients. Patients were randomised by a simple computer-generated randomization chart into Arm A (No Ultrasound guidance) and Arm B (ICB with ultrasound guidance). The uterine perforation rates, tandem length change rates, bladder doses, rectal dose and procedure times were compared. Fischer exact test was used to compare the arms and p value <0.05 considered significant. RESULTS: A total of 160 patients were randomised. With US assistance, the uterine perforation rate was 1.25% (n = 1). In the non-US assistance arm the perforation rate was 12.5% (n = 10) (p = 0.005). Mean time to complete the entire procedure was significantly shortened from 26 min to 19 min favouring the US arm (p = 0.001). Dosimetric assessment between the two groups showed significant decrease in dose received by the various organs at risk with US assistance. CONCLUSION: The present study confirms significant improvement in application quality as well as dosimetry with reduction in procedure time. Trans-Abdominal US should be routinely used for ICB procedures, particularly in resource limited settings.

A systematic review of the role of carbon ion radiation therapy in recurrent rectal cancer.

BACKGROUND: Colorectal cancer is the fourth leading cause of cancer-associated death in the world. The 5-year local recurrence rates in patients undergoing multimodality therapy are approximately 5-10%. The standard approach to treat locally recurrent rectal is re-irradiation followed by surgical resection. Recent reports have suggested that the treatment outcomes with carbon ion radiation therapy (CIRT) in recurrent rectal cancer are promising and have superior results compared to photon therapy. Hence, we performed a systematic review to evaluate the patterns of care and treatment outcomes of recurrent rectal cancer patients treated with CIRT. METHODOLOGY: We performed a systematic search to identify the articles that reported on CIRT use in recurrent rectal cancer. RESULTS: Systematic search of PubMed and Cochrane Central resulted in 98 abstracts. Eight studies fulfilled the predefined inclusion criteria. Among eight studies, one study is a prospective phase I/II study done in Japan; three prospective studies are ongoing (PANDORA-01 trial, HIMAT1351trial, and a phase II study of reirradiation for prior CIRT), and five studies are institutional reports on role of CIRT. These studies were predominantly reported from Japan and Germany. All reports except one were performed in patients who have not received prior radiation. The most commonly utilized treatment prescription was 73.4 Gy (RBE) in 16 fractions over 4 weeks in patients without any prior history of radiation and 36 Gy in 12 fractions over 3 weeks at 3 Gy per fraction in patients with prior photon radiation to the pelvis. There is one ongoing trial assessing the role of carbon ion re-irradiation in patients who had prior CIRT for rectal cancer. CONCLUSION: CIRT holds immense promise in improving outcomes in locally recurrent rectal cancer. There is a need for more multi-institutional prospective clinical trials to assess the role of CIRT.

Impact of surgery and adjuvant treatment on the outcome of extraocular sebaceous carcinoma: a systematic review and individual patient's data analysis of 206 cases.

BACKGROUND: Extraocular sebaceous carcinoma (EOSC) is an aggressive malignancy of the sebaceous gland. Surgery is considered the cornerstone of treatment, but there is lack of clarity about extent and adjuvant treatment. METHODS: We conducted a systematic review and analysis of individual patient data of all published cases of EOSC to look into demography, pattern of care, importance of type of surgery, and other adjuvant treatment and survival outcome. A search of PubMed and Google Scholar was done with the key words sebaceous carcinoma, extraocular sebaceous carcinoma, and Muir-Torre syndrome till December 2017. The data were compiled in an Excel chart and analyzed using SPSS IBM software. RESULTS: Data of 206 patients were retrieved. Median age at presentation was 65 years (range: 11-96 years). Surgery was performed in all except 13 patients. Of these 13, eight were deemed inoperable for extensive disease, and five had metastatic disease. Median PFS and OS for the entire cohort were 84 months (95% CI: 10-158 months) and 92 months (95% CI: 59-126 months). Univariate analysis revealed significantly poor survival for patients with a metastatic disease, regional nodal metastasis, and those with Mohs micrographic or incomplete surgery. CONCLUSION: EOSC is a disease of elderly patients with good prognosis. Complete surgery with regional lymph node dissection is standard treatment. The role of adjuvant radiotherapy is debatable but can be considered in patients with incomplete surgery or high-risk factors.

Hypofractionated radiotherapy with temozolomide in diffuse intrinsic pontine gliomas: a randomized controlled trial.

INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) is the most common form of brainstem glioma. The present study was performed to assess if hypofractionated radiotherapy completed in < 3 weeks with temozolomide improves survival in DIPG. MATERIAL AND METHODS: The present study is a phase II open label randomized trial. The study included newly diagnosed patients with DIPG. Patients in arm A received conventional fractionated RT of 60 Gy in 30 fractions over 6 weeks while patients in arm B received hypo-fractionated radiotherapy of 39 Gy in 13 fractions over 2.6 weeks along with concurrent Temozolomide (TMZ) 75 mg/m2 from day 1 to day 17 followed by adjuvant TMZ for six cycles. The survival analysis was performed with modified intention to treat analysis. RESULTS: A total of 35 patients were randomized. 33 patients were evaluable. 93% (n = 14) of patients in the conventional arm completed treatment while only 17% (n = 3) of the children could complete planned course of treatment in the experimental arm. The median overall survival (OS) was 11 months (95% CI - 7.5 to 14.5 months) in the conventional arm and 12 months (95% CI - 10.5 to 13.5 months) in the experimental arm (p = 0.208). 28% (n = 5) patients in the experimental arm developed grade 3 or 4 hematological toxicity. CONCLUSION: The above study shows that hypofractionated radiotherapy with concurrent and adjuvant temozolomide does not improve OS and has higher hematological toxicity. Conventional radiotherapy remains the standard of care.