Dose-response relationship between volume base dose and tumor local control in definitive radiotherapy for vaginal cancer.

OBJECTIVE: This study aimed to establish the dose-response relationship between volume base dose and tumor local control for vaginal cancer, including primary vaginal cancer and recurrent gynecologic malignancies in the vagina. MATERIALS AND METHODS: We identified studies that reported volume base dose and local control by searching the PubMed, the Web of Science, and the Cochrane Library Database through August 12, 2023. The regression analyses were performed using probit model between volume based dose versus clinical outcomes. Subgroup analyses were performed according to stratification: publication year, country, inclusion time of patients, patients with prior radiotherapy, age, primaries or recurrent, tumor size, concurrent chemoradiotherapy proportion, dose rate, image modality for planning, and interstitial proportion. RESULTS: A total of 879 patients with vaginal cancer were identified from 18 studies. Among them, 293 cases were primary vaginal cancer, 573 cases were recurrent cancer in the vagina, and 13 cases were unknown. The probit model showed a significant relationship between the HR-CTV (or CTV) D90 versus the 2-year and 3-year local control, P values were 0.013 and 0.014, respectively. The D90 corresponding to probabilities of 90% 2-year local control were 79.0 GyEQD2,10 (95% CI: 75.3-96.6 GyEQD2,10). CONCLUSIONS: A significant dependence of 2-year or 3-year local control on HR-CTV (or CTV) D90 was found. Our research findings encourage further validation of the dose-response relationship of radical radiotherapy for vaginal cancer through protocol based multicenter clinical trials.

The top 100 most cited articles in helical tomotherapy: a scoping review.

Objective: The purpose of this scoping review was to explore the top 100 most cited articles in helical tomotherapy (HT) through bibliometric analysis and visualization tools, help researchers comprehensively understand the research hotspots of HT, and provide clear and intuitive network visualization. Methods: The Web of Science Core Collection and the search strategy of "Title (TI)=(tomotherapy)" were used to search for articles related to HT as of 27 May 2023. The top 100 most cited articles were obtained by sorting "citations: highest first". From these top 100 most cited articles, the following information was extracted: journals, years and months, countries, authors, types of tumor treated, and topics. The VOSviewer software was introduced for visualizing all the articles related to HT. Results: The top 100 most cited articles in HT were published between 1999 and 2019. The citation counts of these articles ranges from 326 to 45, with a total of 8,422 citations at the time of searching. The index of citations per year (CPY) ranges from 22.32 to 2.45. These articles originated from 17 countries, with most publications from the United States (n=50), followed by Canada (n=12), Italy (n=10), Germany (n=7) and Belgium (n=5). The International Journal of Radiation Oncology, Biology, Physics published the highest number of articles (n=31), followed by Radiotherapy and Oncology (n=20), Medical Physics (n=13) and Strahlentherapie und Onkologie (n=12). In terms of specific tumor types, head and neck cancer (n=15) is the most common disease, followed by cancers with complex target structures (n=14), breast cancer (n=12), prostate cancer (n=10) and lung cancer (n=8). The most common research topics also include dosimetric comparison (n = 44), quality assurance (n = 12) and Megavoltage CT (n = 8). Conclusion: This scoping review provides a comprehensive list of the 100 most cited articles in HT. This analysis offers valuable insights into the current research directions of HT that can be utilized by researchers, clinicians, and policy-makers.

Dose-effect relationship of linear accelerator based stereotactic radiotherapy for brain metastases.

OBJECTIVE: The purpose of this study is to reveal the dose-effect relationship of linear accelerator (LINAC)-based stereotactic radiotherapy (SRT) in patients with brain metastases (BM). MATERIALS AND METHODS: The PubMed, Cochrane, and Web of Science databases were used to identify studies that reported local tumour control after LINAC-based SRT in patients with BMs. Studies of other approaches that could affect local tumour control, such as whole brain radiotherapy, targeted therapy, and immunotherapy, were excluded from the dose-effect relationship analysis. Data extracted included patient and treatment characteristics and tumour local control. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as the statistically significant level. RESULTS: After literature screening, 19 eligible studies involving 1523 patients were included in the probit model regression analysis. There was no significant dose-effect relationship between nominal BED10 and peripheral BED10 versus 12-month local control probability. There were significant dose effect relationships between the centre BED10 and the average BED10 versus the 12-month local control probability, with P values of 0.015 and 0.011, respectively. According to the model, the central BED10 and the average BED10 corresponding to probabilities of 90% 12-month local control were 109.2 GyBED10 (95% confidence interval (CI): 88.7-245.9 GyBED10) and 87.8 GyBED10 (95% CI: 74.3-161.5 GyBED10), respectively. A 12-month local control rate of 86.9% (95% CI: 81.7-89.7%) and 85.5% (95% CI: 81.2-89.2%) can be expected at a centre BED10 of 80 Gy and an average BED10 of 60 Gy, respectively. CONCLUSION: For patients with BM treated with LINAC-based SRT, more attention should be given to the central and average doses of PTV. A clear definition of the dose prescription should be established to ensure the effectiveness and comparability of treatment.

Dose-effect relationship between dose-volume parameters of residual gross tumor volume and clinical prognosis in MRI-guided adaptive brachytherapy for locally advanced cervical cancer: a single-center retrospective study.

PURPOSE: To investigate the dose-effect relationship between the dose-volume parameters of residual gross tumor volume (GTVres) and clinical prognosis in MRI image-guided adaptive brachytherapy (IGABT) of patients with locally advanced cervical cancer in our center. MATERIALS AND METHOD: The clinical data of 93 patients with locally advanced cervical squamous cell cancer who received external beam radiotherapy (EBRT) combined with IGABT ± chemotherapy in our center were retrospectively analyzed. The disease stage, overall treatment time (OTT), chemotherapy, and the dose-volume parameters D90, D98, and D100 of GTVres, the intermediate-risk clinical target volume (CTVIR), and the high-risk clinical target volume (CTVHR) of the patients were statistically analyzed. Kaplan-Meier and uni- and multivariable Cox regression analyses were used to analyze 2­year overall survival (OS), progression-free survival (PFS), and local control rate (LC). A probit model was employed to assess the dose-effect relationship between the volume and dose-volume parameters of GTVres and 2­year OS, PFS, and LC. RESULTS: The median follow-up time was 19.6 months and 2­year OS, PFS, and LC were 79.6%, 68.8%, and 94.6%, respectively. CTVHR D90 was an independent influencing factor for 2­year PFS (P = 0.041); GTVresBT1 volume was an independent factor for 2­year OS, PFS, and LC (P < 0.001). The probit model showed that at GTVresBT1 volume < 32.86 cm3, the expected 2­year LC was > 90%; at GTVres D98 > 129.12 GyEQD2, the expected 2­year OS was > 90%. CONCLUSION: Both the volume and dose-volume parameters of GTVres are promising predictors in assessment of IGABT prognosis of cervical cancer.

3D-printed vaginal cylindrical template with curved needle channels in MRI-guided vaginal cuff brachytherapy.

Purpose: To present a new technique for the treatment of vaginal cuff recurrences using 3D-printed vaginal cylindrical template (3D-PVCT) with curved needle channels in brachytherapy. Material and methods: Two patients with vaginal cuff tumor treated with external beam radiotherapy and MRI-guided interstitial brachytherapy were selected for the present study. Prior to treatment, a vaginal cylinder with the same size as 3D-PVCT was inserted into the vagina. Magnetic resonance scan was performed to identify target volumes and organs at risk (OARs). By registration techniques, the implantation angle was determined, appropriate needle channels were selected, and the depth of each needle position was recorded. During the actual treatment, patients were under general anesthesia, and real-time guidance of trans-rectal ultrasound was applied referring to a pre-determined treatment plan. Results: For patient No. 1, 9 needles were inserted into the tumor, with 4 curved needle channels and 5 straight channels. For patient No. 2, 7 needles were inserted into the vaginal cuff tumor, with 6 curved needle channels and 1 straight channel. Doses delivered to volumes of targets and OARs for both patients met the EMBRACE II dose constraints. After follow-up of 15 and 18 months, respectively, both patients showed complete response, with no evidence of tumor recurrence. No significant acute or late toxicities were reported. Conclusions: With careful pre-planning, 3D-PVCT provides good target coverage and sparing of OARs. The results from these two patients indicate that this approach is very promising due to its flexibility and potential widespread application in the future.

Dose-effect relationship of stereotactic body radiotherapy in non-small cell lung cancer patients.

OBJECTIVE: To establish the dose effect relationship between the dose parameters of stereotactic body radiation therapy (SBRT) for early non-small cell lung cancer (NSCLC) and the local tumor control rate. MATERIALS AND METHODS: A comprehensive literature search was conducted using PubMed, the Web of Science and the Cochrane databases to determine the articles treated with SBRT in early-stage NSCLC. Original studies with complete prescription dose information, tumor local control rate and other important parameters were screened and reported. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as a statistically significant level. RESULTS: After literature screening, 22 eligible studies were included in probit model regression analysis, involving 1861 patients. There is no significant dose effect relationship between nominal BED10 and peripheral BED10 versus 3 years local control probability. There were significant dose effect relationships between the center BED10 and the average BED10 versus the 3 years local control probability, with P values are 0.001 and < 0.0001, respectively. According to the results of this model, the 3 years local control rate of 90.5% (87.5-92.1%) and 89.5% (86.7-91.0%) can be expected at the center BED10 of 180 Gy or the average BED10 of 140 Gy, prospectively. CONCLUSIONS: For NSCLC treated with SBRT, more attention should be paid to the central dose and average dose of PTV. A set of clear definition in the dose prescription should be established to ensure the effectiveness and comparability of treatment.

Four-Dimensional Image-Guided Adaptive Brachytherapy for Cervical Cancer: A Systematic Review and Meta-Regression Analysis.

Purpose: The ICRU/GEC-ESTRO released the ICRU Report No. 89, which introduced the concept of four-dimensional brachytherapy and ushered in a new era of brachytherapy for cervical cancer. The purpose of this study was to evaluate the local control and late toxicity of four-dimensional brachytherapy in cervical cancer through a systematic review and to reveal the dose-response relationship between the volumetric dose paraments and the local control rate via a probit model. Material and Methods: We identified studies that reported the HR-CTV D90 and local control probabilities by searching the PubMed Database, the Web of Science Core Collection and the Cochrane Library Database through February 1st, 2022. Regression analyses were performed between the HR-CTV D90 and the local control probability using a probit model. Results: Nineteen studies enrolling 3,616 patients were included. The probit model showed a significant relationship between the HR-CTV D90 value and IR-CTV D90 Vs. the local control probability, P < 0.001 and P = 0.003, respectively. The D90 for HR-CTV and IR-CTV corresponding to a probability of 90% local control was 79.1 GyEQD2,10 (95% CI:69.8 - 83.7 GyEQD2,10) and 66.5 GyEQD2,10 (95% CI: 62.8 - 67.9 GyEQD2,10), respectively. The limits for the prescribed dose of 85 GyEQD2,10 for HR-CTV D90 theoretically warranted a 92.1% (95% CI: 90.2% - 95.3%) local control rate, and 87.2% (95% CI: 82.4% - 91.8%) local control probability was expected for 65 GyEQD2,10 to IR-CTV D90. The probit model showed no significant relationship between the D2cc to organs at risk and the probability of grade 3 and above gastrointestinal or genitourinary toxicity. Conclusions: Four-dimensional brachytherapy takes into account uncertain factors such as tumour regression, internal organ motion and organ filling, and provides a more accurate and more therapeutic ratio delivery through adaptive delineation and replanning, replacement of the applicator, and the addition of interstitial needles. The dose volume effect relationship of four-dimensional brachytherapy between the HR-CTV D90 and the local control rate provides an objective planning aim dose.

Three-dimensional image-guided combined intracavitary and interstitial high-dose-rate brachytherapy in cervical cancer: A systematic review.

PURPOSE: To evaluate the local control and toxicities of three-dimensional image-guided combined intracavitary and interstitial (IC/IS) high-dose-rate brachytherapy (BT) in cervical cancer through a systematic review. METHODS AND MATERIALS: A systematic review of relevant studies was performed through the PubMed, Web of Science, and Cochrane Library databases through May 10, 2020. Articles reporting on IC/IS technology, volumetric doses to high-risk clinical target volume (HR-CTV) and organs at risk (OARs), tumor control and/or treatment-related side effects were identified. The key information, including the type of applicator, implantation technology, characteristics of implantation, volumetric doses, tumor control, and/or treatment-related side effects, was extracted. A probit model analysis between HR-CTV D90 and tumor local control was performed. RESULTS: Twelve studies encompassing 520 patients were included in the probit model between HR-CTV D90 and the local control rate. The probit model showed a significant relationship between the HR-CTV D90 value and the local control probability, p = 0.003. The prescribed dose of 85 GyEQD2,10 would in theory warrant an 87.4% (95% confidence interval 82.5%-90.5%) local control rate. CONCLUSION: IC/IS BT is an appropriate method to achieve a high therapeutic ratio for tumors with large volumes or poor responses after external irradiation in cervical cancer. The probit model showed that the dose escalation of HR-CTV D90 was helpful to improve the local tumor control rate.

Predictive value of Excel forms based on an automatic calculation of dose equivalent in 2 Gy per fraction in adaptive brachytherapy for cervical cancer.

PURPOSE: External beam radiotherapy (EBRT) combined with brachytherapy (BT) is the standard mode of radical radiotherapy for locally advanced cervical cancer. The cumulative equivalent doses in 2 Gy per fraction (EQD2) is an important basis for estimating the probability of local control of tumors and monitoring the occurrence of side effects in normal tissues. The purpose of this study was to explore the predictive value of Excel forms based on an automatic calculation in radical adaptive BT for cervical cancer. MATERIAL AND METHODS: A retrospective analysis of 119 patients suffering from cervical cancer, treated with radical radiotherapy. All patients were treated with EBRT and adaptive BT. EBRT prescribed dose was 42.0-50.4 Gy in 21-28 fractions. BT nominal prescribed dose was 28 Gy in 4 fractions, separated by one week. Total EQD2 prediction at nth (n = 1-3) BT (TEPBn) or actual cumulative EQD2 (ACEQD2) can be calculated automatically by inputting the physical dose based on an in-house designed application. The relationship between TEPBn and ACEQD2 was evaluated, and the predictive value of Excel forms based on the automatic calculation was analyzed. RESULTS: For the volume of high-risk clinical target, there was a significant decrease between BT1 and BT2. Similarly, for the volume of intermediate-risk clinical target, there was a significant decrease between BT2 and BT3. The sensitivity ranges of TEPB1, TEPB2, and TEPB3 prediction were 74.5-91.3%, 83.7-95.7%, and 92.9-99.1%, respectively, and the specificity ranges were 46.7-80.0%, 53.3-90.5%, and 66.7-90.5%, respectively. CONCLUSIONS: The in-house designed application has the function of quickly reading dose-volume histogram (DVH) parameters from the treatment planning system, which allows for balance between the total dose to target volumes and organs at risk (OARs). Excel forms based on EQD2 automatic calculation presents high predictive accuracy.

Bibliometric analysis of the 100 most cited articles on cervical cancer radiotherapy.

PURPOSE: To identify the 100 most cited research articles on cervical cancer radiotherapy. METHODS: The Web of Science and Scopus databases were searched to identify the 100 most cited articles on cervical cancer radiotherapy as of September 29, 2019. Articles were ranked based on the total citations received from 2 databases. One hundred articles about radiotherapy for cervical cancer were identified. The following important information was extracted: author, journal, year and month of publication, country or region, and radiotherapy technologies. RESULTS: The 100 most cited articles on cervical cancer radiotherapy were published between 1964 and 2016, and the total citations from 2 databases ranged from 3478 to 211, including a total of 49,262 citations as of September 29, 2019. The index of citations per year ranged from 170.4 to 13.1. These articles were from 16 countries or regions, with most publications being from the United States (n = 38), followed by Austria (n = 15), Canada (n = 8), France (n = 8) and the United Kingdom (n = 7). The International Journal of Radiation Oncology, Biology, Physics produced the most articles (n = 42), followed by Radiotherapy and Oncology (n = 13), Cancer (n = 8) and Journal of Clinical Oncology (n = 7). These articles were categorized as original studies (n = 86), recommendations (n = 5), guidelines (n = 5) and reviews (n = 4). Of the 100 most cited articles, intracavitary brachytherapy (n = 50) and 3-dimensional conformal radiotherapy (n = 34) were the most commonly used treatment techniques. CONCLUSION: To the best of our knowledge, this is the first report and analysis of the most cited articles on cervical cancer radiotherapy. This bibliographic study presents the history of technological development in external radiation therapy and brachytherapy. Brachytherapy is an indispensable part of radiotherapy for cervical cancer. The International Journal of Radiation Oncology Biology Physics is the journal with the most publications related to cervical cancer radiotherapy.

The 100 most cited articles in prostate cancer brachytherapy: systematic review and bibliometric analysis.

PURPOSE: The aim of this study was to identify the 100 most cited research articles in prostate cancer brachytherapy (PCB) and to review the characteristics of these citation. MATERIAL AND METHODS: The Web of Science Core Collection was used to identify the 100 most cited articles in PCB as of December 31st, 2019. The following important information was extracted: year and month of publication, title, journal, country of origin, authors, type of article, treatment modality, and topics. RESULTS: The 100 most cited articles in PCB were published between 1999 and 2018, and the number of citations ranged from 455 to 54; these articles had collectively been cited 10,331 times at the time of search. These articles were from 11 countries, with most publications being from the United States (n = 61), followed by Canada (n = 10), the United Kingdom (n = 8), and Germany (n = 5). The "International Journal of Radiation Oncology, Biology, Physics" published the most articles (n = 47), followed by the "Journal of Urology" (n = 11), "Radiotherapy and Oncology" (n = 10), "Cancer" (n = 7), and "Urology" (n = 6). Permanent interstitial brachytherapy (n = 52) was the most widely used treatment modality, followed by temporary brachytherapy (n = 45). Disease control (n = 51) was the most common topic, followed by side effects (n = 44) and quality of life (n = 27). CONCLUSIONS: The bibliometric analysis presents a detailed list of the 100 most cited articles in prostate cancer brachytherapy. There are clear recommendations for treatment with prostate cancer brachytherapy. The goal of prostate cancer brachytherapy is to improve long-term outcomes and quality of life.

Dose-effect response in image-guided adaptive brachytherapy for cervical cancer: A systematic review and meta-regression analysis.

PURPOSE: This study aimed to integrate and update the dose-effect relationship between volumetric dose and local control for cervical cancer brachytherapy. METHODS AND MATERIALS: We identified studies that reported high-risk clinical target volume (HR-CTV) D90 and local control probability by searching PubMed, Web of Science, and the Cochrane Library databases through Oct 27, 2019. The regression analyses were performed using a probit model between HR-CTV D90, D100, intermediate-risk clinical target volume (IR-CTV) D90, and dose to Point A vs. local control probability. Subgroup analyses were performed according to stratification: time of local control, income level of the country or region, stage of cancer, pathology, mean volume of HR-CTV, dose rate, image modality, concurrent chemoradiotherapy proportion, interstitial proportion, and mean overall treatment time. RESULTS: Thirty-three studies encompassing 2893 patients were included. The probit model showed a significant relationship between the HR-CTV D90 value and the local control probability, p < 0.0001. The D90 corresponding to a probability of 90% local control was 83.7 GyEQD2,10 (80.6-87.8 GyEQD2,10). Of the 33 studies included in our analysis, eight studies, including 1172 patients, reported the IR-CTV D90 value, ranging from 59.1 GyEQD2,10 to 72.3 GyEQD2,10. The probit model also showed a significant relationship between the IR-CTV D90 value and the local control probability, p = 0.0464. The 60 GyEQD2,10 for IR-CTV D90 corresponded to an 86.1% local control probability (82.0%-89.8%). CONCLUSIONS: A significant dependence of local control on HR-CTV D90 and IR-CTV D90 was found. A tumor control probability of >90% can be expected at doses >84 GyEQD2,10 and 69 GyEQD2,10, respectively, based on an updated meta-regression analysis.

The 100 most cited articles in cervical cancer brachytherapy.

PURPOSE: This study aimed to identify the 100 most cited research articles on cervical cancer brachytherapy. METHODS AND MATERIALS: The Institute for Scientific Information Web of Science was used to identify the 100 most cited articles in cervical cancer brachytherapy as of July 5, 2019. The following important information was extracted: journal, year and month, country of region, author, type of article, type of dose rate, type of radionuclide, and image modality for brachytherapy planning. RESULTS: The 100 most cited articles in cervical cancer brachytherapy were published between 1981 and 2016, and the citations ranged from 858 to 49, which collectively had been cited 11,372 times at the time of searching. The index of citations per year ranged from 63.56 to 1.43. These articles were from 16 countries or regions, with most publications being from the United States (n = 27), followed by Austria (n = 26), Japan (n = 10), France (n = 7), and the Netherlands (n = 7). The International Journal of Radiation Oncology, Biology, Physics produced the most articles (n = 46), followed by Radiotherapy and Oncology (n = 39) and Gynecologic Oncology (n = 5). These articles were categorized as original studies (n = 75), reviews (n = 2), editorials (n = 2), surveys (n = 2), guidelines (n = 3), and recommendations (n = 6). A high dose rate (n = 69) was the most widely used, dose rate followed by a low dose rate (n = 20) and pulsed dose rate (n = 16). CONCLUSIONS: The bibliometric analysis presents a detailed list of the 100 most cited articles in cervical cancer brachytherapy. This analysis provides an insight into historical developments and enables the important advances in this field to be recognized.

The design of an individualized cylindrical vaginal applicator with oblique guide holes using 3D modeling and printing technologies.

High-dose-rate brachytherapy for cervical cancer after subtotal hysterectomy using standardized applicators cannot achieve a good absorbed-dose coverage of the target volume in special tumor morphologies and topographies due to the steep dose gradient. The aim of this pictorial essay is to present an individualized cylindrical vaginal applicator with oblique guide holes using 3D modeling and printing technologies used at the China-Japan Union Hospital of Jilin University for cervical cancer patients. We use images to describe the steps of this method.

Image-guided high-dose-rate interstitial brachytherapy boost in the radical radiotherapy for a huge metastatic carcinoma of cervical lymph nodes from an unknown primary site.

The purpose of this article was to report the treatment effect of image-guided high-dose-rate interstitial brachytherapy boost in the radical radiotherapy for a huge metastatic carcinoma of cervical lymph nodes from an unknown primary site. The patient was a 75-year-old male. A diagnostic biopsy showed metastatic squamous cell carcinoma and the tumour size was 7.5×6.5×11.5cm3 before treatment (N3; AJCC 7th). After external beam radiotherapy with a dose of 60Gy in 30 fractions, the residual tumour (6.2×4.7×6.0cm3) was treated with image-guided high-dose-rate interstitial brachytherapy boost under ultrasound guidance. The brachytherapy dose was 16Gy in four fractions of 4Gy each. Removal of the huge metastatic tumour was securely achieved by high dose rate interstitial brachytherapy guided with ultrasound scanning. The refractory tumour in the patients healed uneventfully after image-guided high-dose-rate interstitial brachytherapy without recurrence during the 24 months of follow-up. The image-guided high-dose-rate interstitial brachytherapy boost may be a proposed treatment strategy for metastatic carcinoma of cervical lymph nodes from an unknown primary site with radical radiotherapy, especially for huge residual tumour.

Hypoxia-induced autophagy promotes EGFR loss in specific cell contexts, which leads to cell death and enhanced radiosensitivity.

Treatment failure through radioresistance of tumors is associated with activation of the epidermal growth factor receptor (EGFR). Tumor cell proliferation, DNA-repair, hypoxia and metastases-formation are four mechanisms in which EGFR signaling has an important role. However, the effect of hypoxia on EGFR expression is still controversial. In this study, we demonstrated that hypoxia enhanced EGFR expression and sustained cell survival in SiHa, CAL 27 and A549 cells at both low and high cell desnities, while in MCF-7, MDA-MB-231 and HeLa cells, EGFR and cell survival were regulated by hypoxic treatment in a cell-density dependent manner: upregulated at low cell density and downregulated at high cell density. In MCF-7 and HeLa xenografts in nude mice, EGFR expression varied inversely with the pimonidazole level that was used as an indicator of hypoxia, accordant with the effect of hypoxia at high cell density in vitro. Hypoxia induced more remarkable cell autophagy at high cell density than at low cell density. Autophagy inhibitor 3MA, rather than proteasome inhibitor MG132 inhibited hypoxia-mediated EGFR loss and shifted cell death to cell survival in HeLa cells. The MCF7 cells' sensitivity to ionizing radiation (IR) under hypoxia was also conditional on the cell densities when the hypoxia treatment was introduced, inversely associated with the expression levels of EGFR. Altogether, hypoxia can decrease EGFR expression in some cell lines by enhancing autophagy at high cell density, leading to cell death and hypersensitivity to radiotherapy. This study may help to understand how hypoxia influences EGFR expression and radiosensitivity.

Dosimetric research into target regions and organs at risk in three-dimensional intracavitary brachytherapy techniques for Chinese patients with cervical carcinoma.

The present study aimed to compare the dosages of target regions and organs at risk (OARs) in 3D intracavitary brachytherapy (ICBT) and conventional 2D ICBT for Chinese patients with cervical carcinoma. ICBT was performed in a total of 66 patients with Stage IB to IVA cervical carcinoma who had not received surgery but who had received whole-pelvic external-beam radiotherapy (EBRT). Plans for the 3D-ICBT and the conventional 2D-ICBT were individually designed for every patient. The dosages differences between the target regions and the OARs in patients with each of the various stages of cervical carcinoma were compared between the two ICBT plans. There was no significant difference in the dose at Point A between the two ICBT plans. However, the CTVhr-D90, CTVhr-D100 and CTVir-D90 in 3D-ICBT were much higher than in 2D-ICBT, especially in Stage IIB (P < 0.05). As compared with conventional 2D-ICBT, the dosages of DICRU and D2.0cm3 in the rectum/bladder, and D2.0cm3 in the sigmoid/small bowel were decreased significantly in 3D-ICBT (P < 0.05). For patients with Stage IIA, IIB and IIIB, the D2.0cm3 in the rectum/bladder was significantly reduced in 3D-ICBT (P < 0.05). It was demonstrated that, in Chinese patients, 3D-ICBT for cervical carcinoma could optimize the target coverage and reduce the dosages to the OARs compared with conventional 2D-ICBT.

Image-guided high-dose-rate intracavitary brachytherapy technique for nasal keloid - a case report.

The aim of this study is to report an uncommon case of nasal keloid treated with adaptive image-guided high-dose-rate (HDR) intracavitary brachytherapy. A 34-year-old female presented with nasal keloid after facial trauma was treated with scar resection and HDR intracavitary brachytherapy with a customized eccentric applicator. The total dose was 21 Gy in 6 fractions. During 3 years of follow-up, there was no evidence of recurrence at the local site, and no complications. In conclusion, HDR intracavitary brachytherapy is an effective way to prevent the recurrence of nasal keloids post-surgery.

Image-guided high-dose-rate interstitial brachytherapy - a valuable salvage treatment approach for loco-regional recurrence of papillary thyroid cancer.

PURPOSE: To report the treatment effect of image-guided high-dose-rate (HDR) interstitial brachytherapy for refractory recurrence of papillary thyroid cancer (PTC). CASE REPORT: This 66-year-old female presented with recurrence 5 years after thyroidectomy for PTC. Despite external irradiation and radioactive (131)I, the lesion expanded as 3.7 × 3.0 × 2.3 cm(3) and 2.0 × 1.5 × 1.5 cm(3). The locoregional recurrent tumor was treated with image-guided HDR interstitial brachytherapy. The total dose of 30 Gy in 6 fractions were delivered on the whole recurrent tumor. RESULTS: Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy guided with ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) scanning. The refractory tumor in the patients healed uneventfully after HDR interstitial brachytherapy without recurrence during the 14 months of follow-up. CONCLUSIONS: The image-guided HDR interstitial brachytherapy may be a valuable salvage treatment approach for refractory recurrence of PTC.

Interstitial brachytherapy technique for chest wall refractory recurrence of breast cancer.

PURPOSE: To report the treatment effect of interstitial brachytherapy for chest wall locoregional recurrence of breast cancer. MATERIAL AND METHODS: This 44-year-old female presented with chest wall recurrence seven years after modified radical mastectomy for stage II breast cancer. Despite external beam radiation and chemotherapy, the lesion expanded as 5.3 × 5.1 × 3.0 cm(3), and 8.0 × 5.1 × 4.0 cm(3). The locoregional recurrent tumor was treated with interstitial brachytherapy under ultrasound guidance. The brachytherapy dose was 30 Gy in 6 fractions of 5 Gy each. RESULTS: Removal of the recurrent tumor was securely achieved by interstitial brachytherapy guided with ultrasound scanning. The refractory tumor in patient healed uneventfully after interstitial brachytherapy without recurrence during the 7 months of follow-up. CONCLUSIONS: The ultrasound-guided interstitial brachytherapy may be effective for refractory recurrence of breast cancer.