Effect Of Intensity-modulated Radiotherapy Research Articles

Outcomes in patients with high- and very high-risk localized prostate cancer treated with definitive IMRT and long-term hormone therapy.

The aim of this study was to evaluate the effectiveness of intensity-modulated radiation therapy in combination with long-term androgen deprivation therapy for high-risk and very high-risk localized prostate cancer while also investigating factors associated with the therapeutic effect. Men who fulfilled criteria for the National Comprehensive Cancer Network high-risk or very high-risk localized prostate cancer and were treated with definitive intensity-modulated radiation therapy (74-78Gy) of the prostate and the seminal vesicle combined with androgen deprivation therapy in our institution from 2007 to 2016 were identified (n=197). In principle, patients received androgen deprivation therapy for 3-6months before radiation, concurrently, and for 2years after completion of intensity-modulated radiation therapy. The median follow-up period was 96months. The 5-year and 10-year overall survival rates in the overall population were 96.9% and 89.3%, respectively. The 5-year and 10-year cumulative incidence rates of biochemical failure were 2.5% and 16.3% in the high-risk group, and 8.6% and 32.0% in the very high-risk group, respectively, indicating a significant difference between the two groups (P=0.023). Grade Group 5 and younger age (cutoff: 70years old) were independent predictors of recurrence (P=0.016 and 0.017, respectively). Patients exhibiting biochemical failure within <18months after completion of androgen deprivation therapy displayed an increased risk of cancer-specific mortality (P=0.039) when contrasted with those who had a longer interval to biochemical failure. Patients with the National Comprehensive Cancer Network very high-risk prostate cancer, particularly those with Grade Group 5 and younger age, showed worse outcomes following intensity-modulated radiation therapy and long-term androgen deprivation therapy.

The cost effectiveness of intensity-modulated radiation therapy and three-dimensional conformal radiotherapy in the treatment of head and neck cancers

PurposeIntensity-modulated radiotherapy is developed as a replacement for 3-dimensional conformal radiation therapy. Considering the difference in costs and effectiveness of these interventions, the aim of this study was to compare the cost effectiveness of intensity-modulated radiation therapy and three-dimensional conformal radiotherapy in the treatment of head and neck cancer in east of Iran.MethodsA Markov model including six states based on xerostomia and dysphagia was developed to estimate the incremental cost effectiveness ratio from the perspective of societal. Cost and quality of life data were collected from 97 respondents via a checklist and EuroQol-5Dimension questionnaire. The robustness of results was examined by deterministic and probabilistic sensitivity analysis. All analysis were conducted with Treeage software.ResultsThe results of this study showed that the cost and quality adjusted life years for 3-dimensional conformal radiation therapy were 9209.76 and 3.63 respectively. However, the cost and quality adjusted life years for intensity-modulated radiotherapy were 12562.90 and 3.17 respectively. Therefore, 3-dimensional conformal radiation therapy produced 0.45 more quality adjusted life years than intensity-modulated radiotherapy and saved $3353. According to the incremental cost effectiveness ratio, 3-dimensional conformal radiation therapy as compared to intensity-modulated radiotherapy saved $7367.27 per quality adjusted life years. These results confirmed by sensitivity analysis.ConclusionThis study concluded that in the treatment of head and neck cancer, the 3-dimensional conformal radiation therapy method appears to be cost-effective when compared with intensity-modulated radiotherapy.

Long-Term Patient-Reported Quality of Life of Anal Cancer Survivors Treated With Intensity Modulated Radiation Therapy and Concurrent Chemotherapy: Results From a Prospective Phase II Trial

Intensity modulated radiation therapy (IMRT) has confirmed its superiority in improving acute treatment-related toxicities in anal cancer, without compromising tumor control. However, the effect of IMRT on long-term quality of life (QOL) is poorly documented. The study prospectively evaluated the long-term patient-reported QOL after IMRT-based chemoradiation in anal cancer. Fifty-eight patients treated with IMRT and concurrent 5 fluorouracil/mitomycin-C were enrolled in the study. A prespecified secondary endpoint was prospective evaluation of long-term QOL. Fifty-four patients underwent QOL evaluation at baseline, after treatment, and during follow-up until 60 months, with European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) scales and the Colorectal Cancer-Specific Quality Of Life Questionnaire (QLQ-CR29) scales. The QOL scores at baseline and posttreatment periods were compared. For QLQ-C30, at 60 months, the mean scores of global health status, all functional scales, and all symptoms except diarrhea had improved, indicating normalization of QOL. Clinically and statistically significant improvements in the global health status (15.4; P=.003), role functioning (19.3; P=.0017), emotional functioning (18.9; P=.008), and social functioning (29.8; P ≤ .001) were observed. Diarrhea persisted as a concern over the years (P=.172). For European Organization for Research and Treatment of Cancer QLQ-CR29, rectal pain (-38.6; P=.001), mucous or blood discharge per rectum (-22.8; P=.005), and perianal soreness (-37.3; P ≤ .001) were improved both clinically and statistically. Clinically significant fecal leakage was reported by 16% of patients (5.6; P=.421). Volumes receiving 45 and 54 Gy were independent predictors for fecal incontinence. Clinically and statistically significant urinary incontinence occurred in 21% of patients (17.5; P=.014). Deterioration of dyspareunia was clinically significant (26.7; P=.099) at 60 months. Compared with historical data, IMRT is associated with reduced long-term effects on QOL. The majority of patients treated with IMRT experienced clinically significant recovery of function and improvement in QOL over 5 years after completion of treatment. Specific toxicities such as chronic diarrhea, fecal incontinence, and urinary and sexual dysfunction were primarily responsible for deterioration of the long-term QOL. Future research aimed at reducing such toxicities is needed to further improve long-term QOL in anal cancer.

IMRT use for locally advanced cervix cancer: Do patients at safety-net hospitals have equal access to this technology? (285)

<b>Objectives:</b> Intensity-modulated radiation therapy (IMRT) is an advanced technique that allows for conformal delivery of radiation to a planned treatment area while minimizing radiation to organs at risk. Utilization of this technique in the definitive treatment of cervical cancer can be variable but has been associated with reduction of acute and late genitourinary and gastrointestinal side effects of radiation. The objective of this study was to identify the trends associated with IMRT use for patients undergoing definitive treatment for cervical cancer. <b>Methods:</b> This was a retrospective cohort study of patients with FIGO stage IB2-IVA cervical cancer from 2009-2020. All patients receiving curative-intent treatment for locally advanced cancer were included, with chemoradiation therapy followed by brachytherapy as the standard. At our institution, patients were referred from a network of safety net hospitals and also a group of academic medical centers and received radiation at one site. The primary outcome was the rate of IMRT versus three-dimensional conformal radiotherapy (3DCRT) usage. Secondary outcomes were progression-free survival (PFS) and overall survival (OS). We used Chi-square, logistic regression, Kaplan Meier log-rank test, and Cox regression with significance p<0.05. <b>Results:</b> One hundred thirty-eight patients were diagnosed with locally advanced cervical cancer in our cohort. The median age at diagnosis was 54 years (range: 23-83). Ninety-two (67%) patients received conventional 3CDRT, and 46 (33%) patients received IMRT. IMRT use increased from 0% in 2011 to 100% in 2020 (p<0.001). Age at diagnosis, race, insurance, and referring hospital were not correlated with IMRT use. In univariate regression, diagnosis after 2015 (OR: 34.22, 95% CI: 7.81-149.98), radiation dose greater than 50 Gray (OR: 2.60, 95% CI: 1.05-6.46), and need for paraaortic boost (OR 2.86, 95% CI: 1.09-7.52) were associated with IMRT. In multivariate regression, only diagnosis after 2015 was predictive of IMRT use (OR: 30.37, 95% CI: 6.58-140.36) when controlling for radiation dose and indication for paraaortic boost. IMRT use was not associated with a PFS benefit (p=0.903) nor an OS benefit (p=0.642). The median follow-up was 28 months (range: 3-122). Only stage was predictive of PFS (HR: 2.21, 95% CI: 1.41-3.44) and OS (HR: 2.63, 95% CI: 1.44-4.77) when controlling for race, insurance, and referring hospital. <b>Conclusions:</b> IMRT use has increased significantly over the last decade for locally advanced cervical cancer. In our care model, where patients referred from both a network of public and private hospitals undergo radiation at one central facility, there were no disparities in receipt of IMRT according to race, insurance, or referring hospital. There were no effects of IMRT on PFS or OS. Additional studies are warranted to correlate our institutional experience with national trends in IMRT usage. Table 1

Investigation of the Effect of Radiotherapy Dose on Chewing and Swallowing Structures in Head and Neck Cancer Patients Treated with Concomitant Chemoradiotherapy.

Intensity-modulated radiotherapy (IMRT) is a treatment method that is used in the treatment of head and neck cancers. Impairment of chewing and swallowing functions in the early and late periods of radiotherapy is frequent. Therefore, revealing the dose-effect relationship is important. The main purpose of this study is to investigate the dose-effect relationship between chewing and swallowing structures objectively via a standardized videofluoroscopy protocol. The study included 35 participants treated with chemo-IMRT. A videofluoroscopic swallowing study (VFSS) was performed before IMRT, and 3 and 6months after IMRT. VFSS results were scored according to the Modified Barium Swallow Impairment Profile (MBSImP) and the Penetration-Aspiration Scale (PAS). Maximum interincisor mouth opening, body mass index (BMI), and Functional Oral Intake Scale levels were determined in these cases. The quality of life of participants was evaluated. There was a significant increase in PAS and MBSImP scores and a significant decrease in BMI scores of the patients after treatment. Xerotomy and sticky saliva complaints increased after treatment. The dose to the mastication muscles (> 40Gy) and the temporomandibular joint (> 46Gy) were found to be associated with a decrease in BMI; the dose to the superior pharyngeal constructor muscle (> 58Gy) was found to be associated with pharyngeal stripping wave. The presence of aspiration was associated with the inferior pharyngeal constructor muscle, glottic larynx, supraglottic larynx, and upper esophageal sphincter. Important findings to emerge from this study include detected toxic dose limits. These findings may guide physicians to minimize the side effects of IMRT.

Dosimetric effect of intensity-modulated radiation therapy for postoperative non-small cell lung cancer with and without air cavity in the planning target volume.

To evaluate the dosimetric effect of intensity-modulated radiation therapy (IMRT) for postoperative non-small cell lung cancer (NSCLC), with and without the air cavity in the planning target volume (PTV). Two kinds of IMRT plans were made for 21 postoperative NSCLC patients. In Plan-0: PTV included the tracheal air cavity, and in Plan-1: the air cavity was subtracted from the PTV. For PTV, the dosimetric parameters, including Dmean, D98, D95, D2, D0.2, conformity index (CI), and homogeneity index (HI) were evaluated. For organs at risk (OARs), the evaluation indexes, included the V5, V20 and the mean lung dose (MLD) of total lung, the V30, V40, and the mean heart dose (MHD) of heart, the spinal cord Dmax, and the V35 and the mean esophageal dose (MED) of esophagus. The number of segments and MUs were also recorded. Additionally, the correlation between the Plan-1 dosimetric change value relative to Plan-0, the size of air cavity, and the volume proportion of the cavity in the PTV was also analyzed. The Dmean of PTV, D2, D0.2, HI and CI in Plan-1 decreased compared with those in Plan-0. For OARs, the V30, MHD, and MED also decreased. The CI change value of Plan-1 relative to Plan-0 had a significantly negative correlation with the size and the volume proportion of air cavity, and the MED change value also had a significantly negative correlation with the air cavity size. The IMRT plans for patients with postoperative NSCLC can achieve a better target dose distribution and offer an improved sparing of the heart and esophagus by removing the PTV air cavity, while reducing the target conformity. The change value of CI and MED had a significantly negative correlation with the air cavity size.

Factors predictive of the development of hypothyroidism after intensity-modulated radiation therapy for pharyngeal cancer

Background Hypothyroidism is a common adverse event after radiotherapy for head and neck tumors and the incidence need to be re-evaluated because of using intensity-modulated radiotherapy (IMRT). Aims/Objectives Confirm the dose-volume effect of IMRT for pharyngeal cancer on hypothyroidism. Materials and methods This was a retrospective analysis of patients underwent IMRT for pharyngeal cancer from June 2011 to May 2018. Patients were classified into group A (thyroid stimulating hormone (TSH) <5μU/ml), group B (5< =TSH < 10), and group C (10< =TSH) based on TSH over 36 months post-radiation. Radiation dose, thyroid volume, and the proportion of the thyroid that received X Gy or greater (Vx) were measured. Results Fifty-two patients were included in this work. Hypothyroidism developed in 33/52 (63%) patients, 13 in group B and 20 in group C. The mean radiation dose to the thyroid was 49.4 Gy and the median time until hypothyroidism was 39 months after irradiation. Hypothyroidism was significantly related to neck dissection (ND) and radiation dose to the thyroid. Patients whose thyroid received 45 Gy or more (V45) >67% had a significantly higher incidence of hypothyroidism. Conclusions and significance Patients with pharyngeal cancer who had ND and V45 to the thyroid >67% are at risk of hypothyroidism.

Doses of intensity-modulated radiotherapy and its association with cardiac disease in esophageal cancer patients.

BackgroundNo clear guidelines or available studies exist regarding the effects of intensity-modulated radiotherapy (IMRT) of esophageal cancer (EC) on the cardiovascular system. We therefore analyzed a wide range of cardiac vascular dosimetric parameters and clinical characteristics to assess the prognostic factors for EC patients treated with IMRT.MethodsA total of 112 patients receiving IMRT at the Qianfoshan Hospital between July 2012 and May 2017 were retrospectively reviewed. The dose per fraction was 1.8–2.0 Gy, and the total dose range was 54–66 Gy. Kaplan-Meier analysis was used to estimate death due to heart disease. Univariate and multivariate logistic regression models were calculated to test for associations between patient characteristics and dose-volume histogram (DVH) parameters. A t-test and chi-squared or Fisher’s exact test was used to analyze the comparisons.ResultsThe maximum and mean doses received by the heart were 57.34±13.51 and 24.83±11.40 Gy, respectively. Among the parameters examined, which included the maximum dose received by the heart, the mean dose received by the right and left ventricle (RV and LV), and the maximum dose received by the right atrium (RA), the mean dose received by the RV predicted survival and was included in our multivariate analysis. The results indicated that patients with basic heart disease who were undergoing concurrent radiochemotherapy were more likely to have cardiac disease.ConclusionsThis is first study to examine the prognosis of cardiovascular vessels exposed to various radiation doses during the treatment of EC, the findings of which suggest that limiting radiation exposure may be an important measure in IMRT application. These findings of this study may provide theoretical support for prediction of radiation-induced heart disease (RIHD). Furthermore, to curb the risk of RIHD, the modality of chemotherapy also needs to be attentively monitored and managed.

Effect of intensity-modulated radiation therapy on sciatic nerve injury caused by echinococcosis.

Conventional radiotherapy has a good killing effect on femoral echinococcosis. However, the sciatic nerve around the lesion is irreversibly damaged owing to bystander effects. Although intensity-modulated radiation therapy shows great advantages for precise dose distribution into lesions, it is unknown whether intensity-modulated radiation therapy can perfectly protect the surrounding sciatic nerve on the basis of good killing of femoral echinococcosis foci. Therefore, this study comparatively analyzed differences between intensity-modulated radiation therapy and conventional radiotherapy on the basis of safety to peripheral nerves. Pure-breed Meriones meridiani with bilateral femoral echinococcosis were selected as the research object. Intensity-modulated radiation therapy was used to treat left femoral echinococcosis of Meriones meridianus, while conventional radiotherapy was used to treat right femoral echinococcosis of the same Meriones meridianus. The total radiation dose was 40 Gy. To understand whether intensity-modulated radiation therapy and conventional radiotherapy can kill femoral echinococcosis, trypan blue staining was used to detect pathological changes of bone Echinococcus granulosus and protoscolex death after radiotherapy. Additionally, enzyme histochemical staining was utilized to measure acid phosphatase activity in the protoscolex after radiotherapy. One week after radiotherapy, the overall structure of echinococcosis in bilateral femurs of Meriones meridiani treated by intensity-modulated radiation therapy disappeared. There was no significant difference in the mortality rate of protoscoleces of Echinococcus granulosus between the bilateral femurs of Meriones meridiani. Moreover, there was no significant difference in acid phosphatase activity in the protoscolex of Echinococcus granulosus between bilateral femurs. To understand the injury of sciatic nerve surrounding the foci of femoral echinococcosis caused by intensity-modulated radiation therapy and conventional radiotherapy, the ultrastructure of sciatic nerves after radiotherapy was observed by transmission electron microscopy. Additionally, apoptosis of neurons was examined using a terminal-deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and expression of Bcl-2 and Bax in sciatic nerve tissue was detected by immunohistochemical staining and western blot assay. Our results showed that most neurons in the left sciatic nerve of Meriones meridiani with echinococcosis treated by intensity-modulated radiation therapy had reversible injury, and there was no obvious apoptosis. Compared with conventional radiotherapy, the number of apoptotic cells and Bax expression in sciatic nerve treated by intensity-modulated radiation therapy were significantly decreased, while Bcl-2 expression was significantly increased. Our findings suggest that intensity-modulated radiation therapy has the same therapeutic effect on echinococcosis as conventional radiotherapy, and can reduce apoptosis of the sciatic nerve around foci caused by radiotherapy. Experiments were approved by the Animal Ethics Committee of People's Hospital of Xinjiang Uygur Autonomous Region, China (Approval No. 20130301A41) on March 1, 2013.

Intensity-modulated Radiation Therapy for Lymph Node Oligo-recurrence.

This study aimed to evaluate the effect of intensity-modulated radiation therapy (IMRT) on the clinical outcomes of patients with lymph node (LN) oligo-recurrence and a controlled primary tumor. We retrospectively reviewed the medical records of 21 patients diagnosed with LN oligo-recurrence who received IMRT with curative intent. Patients with tumor of various primary sites and histopathological types were included in this study. The 3-year overall survival (OS) and in-field progression-free survival (PFS) rates were 75% and 52%, respectively. Statistical analysis showed that lower dose to the gross tumor volume (GTV) and larger GTV were significantly associated with poorer OS; adenocarcinoma and lower dose to GTV were significantly associated with poorer in-field PFS. No patients experienced severe adverse events. IMRT may provide a safe and effective treatment for patients with LN oligo-recurrence. Tumor dose-escalation sparing normal tissue using IMRT technology may improve the OS and in-field PFS.

The effect of IMRT on acute toxicity in patients with gastric cancer treated with preoperative chemoradiation.

153 Background: Two trials are currently investigating preoperative chemoradiation (CRT) for localized gastric adenocarcinoma. However, radiation therapy (RT) can be associated with relatively high rates of acute toxicity. Newer techniques, such as intensity modulated RT (IMRT), could reduce toxicity by reducing radiation dose to normal structures. Our goal was to compare rates of toxicity and toxicity-related events in patients treated with IMRT compared to 3D conformal RT (3DCRT). Methods: The records of 202 gastric cancer patients treated with preoperative intent RT at our institution from 1998-2018 were retrospectively reviewed. Demographic data, treatment details, acute and late toxicities (CTCAE 4.0 criteria), progression and survival data were recorded. Patients who had stage IV disease were excluded. Statistical analysis included descriptive statistics, Cox regression analysis, and Kaplan-Meier survival. Results: 54% were male and the median age was 63. 82 patients received 3DCRT and 120 patients received IMRT (median 45Gy, IQR, 45-45Gy in each group). 78% of patients in the 3DCRT group and 91% of patients in the IMRT group received neoadjuvant chemotherapy prior to RT. 99% of patients received concurrent chemotherapy. The rate of grade 3-4 acute toxicity was significantly lower in patients treated with IMRT compared to 3DCRT (53% vs. 73%, p = 0.004). The composite rate of toxicity-related events (hospitalization, feeding tube, IV rehydration, or RT break) was also significantly lower in patients treated with IMRT compared to 3DCRT (80% vs. 91%, p = 0.031). 72% of patients who received 3DCRT and 68% of patients who received IMRT underwent subsequent surgical resection. The 3-year OS rate was 58.1% for patients receiving IMRT and 60.2% for patients receiving 3DCRT (p = 0.649). The 3-year PFS rate was 47.5% for patients receiving IMRT and 52.7% for patients receiving 3DCRT (p = 0.486). Conclusions: Our study indicates a marked reduction in the rates of grade 3-4 acute toxicity and toxicity-associated events in patients treated with IMRT compared to 3DCRT. These findings suggest that IMRT should be considered as the radiation modality in patients treated with preoperative CRT for gastric cancer.

Clinical evaluation of intensity-modulated radiotherapy for locally advanced pancreatic cancer

BackgroundThe purpose was to retrospectively evaluate the effect of intensity-modulated radiotherapy (IMRT) on gastrointestinal (GI) toxicities and outcomes compared to three-dimensional conformal radiotherapy (3DCRT) for locally advanced pancreatic cancer (LAPC).MethodsWe included 107 consecutive patients who underwent CRT for LAPC from September 2001 to March 2015; 80 patients underwent 3DCRT and 27 patients underwent IMRT. They were compared for GI toxicities, locoregional progression free survival (LRPFS), distant metastasis free survival (DMS), and overall survival (OS).ResultsMedian radiation dose and fractions for 3DCRT and IMRT were 54 Gy/30 fr. and 48 Gy/15 fr. The regimens of CRT consisted of weekly gemcitabine 250 mg/m2 (for 3DCRT) or 1000 mg/m2 (for IMRT). Acute GI toxicity ≥grade 2 occurred in 32 patients (40%) treated with 3DCRT compared with five patients (19%) treated with IMRT. Late GI toxicity of grade 3 occurred in 10 patients (12%) treated with 3DCRT and one patient (4%) treated with IMRT. Patients who underwent IMRT had superior 1-year LRPFS (73.1% vs. 63.2%, p = 0.035) and 1-year OS (92.3% vs. 68.2%, p = 0.037) as compared with those treated with 3DCRT. Multivariate analysis showed that in IMRT patients, higher dose (≥45 Gy) was an independent factor for better LRPFS and OS.ConclusionsLAPC patients treated with hypofractionated full-dose gemcitabine IMRT had improved OS and LRPFS without increased GI toxicities when compared to those of patients treated with conventionally fractionated low dose gemcitabine 3DCRT. In IMRT patients, higher dose was an independent favorable prognostic factor for better LRPFS and OS, which suggests that dose escalation with IMRT for LAPC is a promising strategy.

Changes in Candida Profile in Patients Undergoing Intensity Modulated Radiotherapy for Head and Neck Malignancies

The increased oral Candida colonization that resulted for radiotherapy often leads to candidiasis. Intensity Modulated Radiotherapy (IMRT) is a technique of delivering radiation with improved dose distributions sparing the surrounding normal tissue and decreasing the ill-effects. Objective: To identify and quantify changes in the Candidal carriage of patients undergoing IMRT for head and neck malignancy. Methods: Saliva from 37 patients undergoing IMRT for head and neck malignancy was collected. The Candida species profile pre- and post-IMRT was evaluated using semi quantitative fungal culture. The changes in the distribution of the growth of Candida species due to IMRT was analyzed using Wilcoxon sign rank test. Results: Twenty-two patients were Candida -positive pre-IMRT, while 24 patients were Candida -positive post-IMRT. Candida species isolates pre-IMRT were C . albicans (63%) , C. tropicalis (26%), C. glabrata (7%) , C. krusei (4%) and post-IMRT, were C. albicans (55%) , C. tropicalis (30%), C. glabrata (12%) and C. krusei (3%). C. albicans showed increased growth post-IMRT in the range of 103 to 104 colony-forming units per ml of saliva (p>0.05). Conclusion: There was no significant effect of IMRT on the distribution of growth of Candida. Candida albicans was the most common species. A change towards non C. albicans species post-IMRT was seen.

Effectiveness of intensity-modulated radiation therapy with simultaneous integrated boost in cervical cancer patients with PET positive lymph nodes

Purpose It is standard for our department to offer intensity-modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB) for all node-positive cervical cancer patients. Multiple institutions have provided reports and here we provide our outcomes using IMRT [Vargo et al. (Int J Rad Oncol Biol Phys 90: 1091–1098, 9), Marnitz et al. (Strahlentherapie und Onkol 191: 421–428, 10), Jung et al. (Anticancer Res 34: 4361–4366, 11), Zhang et al. (J Gynecol Oncol 25: 14–21, 12), Ke et al. (Zhonghua Fu Chan Ke Za Zhi 48: 649–653, 13)] .

Combination of intensity modulated radiotherapy followed treatment with p38 MAPK activation inhibitor inhibits the proliferation of MCF-7 breast cancer cells.

The present study was aimed to investigate the effect of intensity modulated radiotherapy (IMRT) followed by treatment with inhibitor for p38 MAPK, SB203580 on the rate of proliferation in drug resistant MCF-7 breast cancer cells. Interestingly, the results from immuno histochemistry and western blot assays revealed higher level of distribution of activated p38 MAPK in the drug resistant breast cancer tissues compared to the primary tissues. Treatment of the drug resistant MCF-7 cells with SB203580 led to a significant decrease in the phosphorylation of p38 MAPK. Exposure to IMRT caused a significant decrease in the rate of proliferation in drug resistant MCF-7breast cancer cells (P < 0.05). MCF-7 cells were subjected to IMRT for 45 min followed by treatment with SB203580 for 12 h. The results from MTT assay revealed inhibition in the rate of proliferation of MCF-7 cells more efficiently compared to the IMRT or SB203580 when used separately (P < 0.02). The effect of IMRT and SB203580 on inhibition of MCF-7 cell proliferation showed synergistic relation. Since MAPK signaling pathway plays an important role in the development of drug resistance, therefore, inhibition of p38 MAPK activation by the combination of IMRT followed by treatment with inhibitor for p38 MAPK can be a promising strategy for breast cancer treatment. Thus combination of IMRT exposure and treatment with SB203580 can be used for the inhibition of drug resistant breast cancer.

Effect of IMRT and three-dimensional conformal radiotherapy on oral Candida colonization: A comparative study

Aim: To investigate oral candidiasis in patients with head and neck cancer before and after intensity-modulated radiation therapy and three-dimensional conformal radiotherapy (3D CRT) and to explore if there is an association with the type of radiotherapy used and the severity of candidiasis. Materials and Methods: Patients who received radiation therapy (RT) for the treatment of head and neck cancer were divided into two groups: Group 1 consisted of patients (n = 20) who received Intensity modulated radiation therapy (IMRT) and Group 2 (n = 20) consisted of patients who received 3D CRT. Saliva from these patients was collected before and after radiotherapy and evaluated for Candida species using culture method. Results: Significant increase of Candida albicans was seen in patients who underwent 3D CRT as compared to IMRT. Other species of Candida such as Candida tropicalis, Candida glabrata, and Candida krusei showed increase postradiotherapy in both groups, but the change was not significant. Conclusion: Although candidiasis is seen regardless of the type of radiation therapy used, the oral environment is more stable after intensity-modulated radiation therapy as and when compared to 3D CRT. Salivary substitutes and good oral hygiene before, during, and after radiotherapy could be used to increase oral clearance and to decrease the chance of candidiasis.

Intensity-modulated radiotherapy controls nasopharyngeal carcinoma distant metastasis and improves survival of patients.

BackgroundThis study evaluated the distant metastatic outcomes in nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT) plus chemotherapy.Methods530 Non-metastatic NPC patients were retrospectively collected and reviewed after receiving IMRT with or without chemotherapy between June 2006 and December 2011. Patients were treated with one fraction of IMRT daily for 5 days a week for 69.96–74.09 Gy, while 473 (89.2 %) of patients also received chemotherapy.ResultsPatients were followed up for a median follow-up duration of 49 months (range from 5 to 98 months). After treatment, 91 (17.3 %) patients developed distant metastasis. Distant metastasis after treatment was significantly associated with advanced 2010 Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) T staging (p = 0.034), N stage (p < 0.001), 2010 UICC/AJCC stage (p < 0.001), and tumor recurrence (p = 0.029). However, chemotherapy failed to reduce cancer distant metastasis in early stage patients, the distant metastasis rate was 17.5 % in stage III and 24.2 % in stage IVA–B diseases, after IMRT and chemotherapy. The multivariate analysis showed that cancer remission duration, treatment modality, and metastatic site (p < 0.001, p = 0.027 and p = 0.022, respectively) were all independent predictors for overall survival of NPC patients after IMRT and chemotherapy.ConclusionsThis study provided insight into the effects of IMRT plus chemotherapy in the treatment of NPC. Future studies will explore the efficacy of more aggressive systemic therapies for high-risk patients with distant metastasis.

Therapeutic effect of intensity modulated radiotherapy combined with temozolomide on brain metastases

目的 分析调强放疗联合替莫唑胺治疗脑转移瘤的疗效。 方法 回顾性分析2012年1月至2013年12月在山西省肿瘤医院接受治疗的脑转移瘤患者50例，其中采用单纯调强放疗（单纯放疗组）25例，调强放疗联合替莫唑胺治疗（同步放化疗组）25例。采用世界卫生组织（WHO）实体瘤评价标准比较两组临床疗效。 结果 50例脑转移瘤患者均完成治疗。同步放化疗组中，17例患者未完成同步放化疗后6个周期的替莫唑胺辅助化疗。单纯放疗组中，完全缓解3例，部分缓解10例，稳定8例，进展4例，总有效率52 %（13/25），疾病控制率84 %（21/25）；同步放化疗组中，完全缓解5例，部分缓解16例，稳定4例，进展0例，总有效率84 %（21/25），疾病控制率100 %（25/25）。两组有效率及疾病控制率差异有统计学意义（P 0.05）。 结论 调强放疗联合替莫唑胺治疗脑转移瘤有效，但未提高患者的生存率。

Late Toxicities of Intensity-Modulated Radiation Therapy for Head and Neck Rhabdomyosarcoma.

To examine the late effects of intensity-modulated radiation therapy (IMRT) in pediatric patients with rhabdomyosarcoma of the head and neck. All 1-year survivors of pediatric head and neck rhabdomyosarcoma treated with IMRT at a single institution from 1999 to 2014 were assessed for long-term complications. Late toxicities were graded according to CTCAE version 4.03. Among 30 patients, median age at IMRT was 7.4 (1.5-20.8) years, median follow-up was 7.7 (1.2-14.4) years, and median IMRT dose was 50.4 (36-50.4) Gy. Tumor subsites included parameningeal (80%), orbit (13%), and other (7%). Common late toxicities were facial disfigurement (n = 23, 77%), growth hormone deficiency (n = 11, 37%), cataract (n = 10, 34%), and dental problems (n = 10, 33%). Twenty-two patients (73%) had ≥2 late toxicities and 14 patients (47%) had ≥3 late toxicities. Seventeen patients (57%) experienced grade 2 toxicity and 10 patients (33%) had grade 3 toxicity. Grade 3 toxicities included visual disturbance, cataract, facial disfigurement, chronic sinusitis/otitis, and hearing loss. Severe facial deformity was noted in nine patients (30%), and three patients underwent cosmetic surgery. Patients with severe facial deformity were treated at younger ages (median 6.0 years vs. 8.1 years for patients with no/nonsevere facial deformity) and more likely to have infratemporal fossa tumors. There were no secondary solid malignancies. Late radiation toxicities are common in survivors of pediatric head and neck rhabdomyosarcoma treated with IMRT. While the majority of late effects are mild-moderate, they can significantly impact quality of life, particularly facial disfigurement.

Brain dose-sparing radiotherapy techniques for localized intracranial germinoma: Case report and literature review of modern irradiation

We examined the effects of intensity-modulated radiation therapy with dose-sparing and avoidance technique on a pediatric patient with localized intracranial germinoma. We also reviewed the literature regarding modern irradiation techniques in relation to late neurocognitive sequelae. A patient with a localized intracranial germinoma in the third ventricle anterior to the pineal gland received a dose-sparing intensity-modulated radiation therapy. The planning was compared to the radiation oncologist's guide of organs at risk and dose constraints for dosimetric analyses. The patient received radiation therapy alone. The total dose was 54Gy delivered in 2.0Gy fractions to the primary tumour and 37Gy in 1.4Gy fractions to whole ventricles using a dose-sculpting plan. Dosimetry analyses showed that dose-sparing intensity-modulated radiation therapy delivered reduced doses to the whole brain, temporal lobes, hippocampi, cochleae, and optic nerves. With a follow-up of 22 months, failure-free survival was 100% for the patient and no adverse events during radiation treatment process. Intensity-modulated radiation therapy with dose sparing and avoidance technique can spare the limbic circuit, central nervous system, and hippocampus for pineal germ cell tumours. This technique reduces the integral dose delivered to the uninvolved normal brain tissues and may reduce late neurocognitive sequelae caused by cranial radiotherapy.