Method to assess the need for re-planning HDR brachytherapy tandem and ring treatments

High dose rate (HDR) brachytherapy procedures for cervical cancer require multiple applicator insertions for multiple (typically 5) fractions of a single plan, which carries a risk for variability in applicator position between fractions. Due to applicator displacement relative to patient anatomy, the dose to nearby organs-at-risk (OARs) may vary significantly from one fraction to the next. The purpose of this study was to evaluate the effect of changes in HDR tandem and ring (T&R) applicator position on doses to nearby OARs and to present a quick and simple method to estimate doses to OARs inter-fractionally without having to perform a re-plan. Ninety CT image sets for 20 patients, ages 44 to 86, undergoing T&R-based HDR for cervical cancer were used retrospectively for this study. Measures of applicator positional and angular changes relative to the bony anatomy were obtained using image fusion in MIM software, between the planning CT (plan CT) and the CT on the treatment day (CT-TX). Dosimetric data were determined, also using MIM software, using the original (first fraction) dose distribution applied to organs at risk (rectum and bladder), transferred via rigid registration from the plan CT to each CT-TX. Bladder and rectum contours were also transferred from each plan CT to each CT-TX and were tweaked manually to match anatomy on each CT-TX and examined visually for appropriateness. Differences in translation and rotation of the T&R applicator between the planning CT and subsequent individual fractions were recorded and plotted against dose differences between each fraction of treatment and the original (first) fraction. Absolute dose (D2cc) and volume (V50) differences vs positional shifts were calculated and plotted, and the Pearson Product-Moment correlation coefficient between dose parameters and measured positional shifts was determined. Average dosimetric differences between planned dose and subsequent fractional doses obtained through rigid registration were 1.48 ± 1.92 Gy, 14.91 ± 11.92 cm3, 0.56 ± 0.93 Gy, and 1.77 ± 2.18 cm3 for Bladder D2cc, Bladder V50, Rectum D2cc, and Rectum V50, respectively. Correlation between Bladder V50 and sagittal plane rotation gave an r2 of 0.4, showing the most correlation of all parameters studied. Bladder dose and volume increased by a maximum of about 2.7 Gy and 50 cm3 overall for Bladder D2cc and Bladder V50, respectively. Bladder V50 was most sensitive to T&R applicator displacements. We have quantified the effects of applicator positional changes on dose changes for the bladder and rectum. Even large changes in applicator position between fractions did not result in significant changes in dose to these normal tissues, indicating that adaptive re-planning is not necessary.

Can normalized carcinoembryonic antigen following neoadjuvant chemoradiation predict tumour recurrence after curative resection for locally advanced rectal cancer?

AIM

The aim of this work was to evaluate whether normalized carcinoembryonic antigen (CEA) following neoadjuvant chemoradiation predicts the prognosis following curative resection in locally advanced rectal cancer.

METHOD

Patients who underwent neoadjuvant chemoradiation and curative resection for locally advanced rectal cancer between 2010 and 2015 were divided into three groups: Group A (n = 119, normal-to-normal): normal CEA before and after neoadjuvant chemoradiation; Group B (n = 37, high-to-normal): elevated CEA before and normal CEA after neoadjuvant chemoradiation; Group C (n = 36, high-to-high): elevated CEA before and after neoadjuvant chemoradiation. Overall and disease-free survival were compared. Univariate and multivariate analyses identified potential predictors for recurrence.

RESULTS

One hundred and ninety two patients [median age 59 years (range 31-87), 65.1% male] were identified: 54.7% had low rectal cancer: 12.5% were clinical stage T4 and 70.3% were clinically node positive; 21.9% achieved complete pathological response; 24.5% had abdominoperineal resection (APR); and 70.3% underwent adjuvant chemotherapy following curative resection. Significantly more patients in Group C underwent APR (p = 0.0209), had advanced pathological T stage (P = 0.0065) and a higher prevalence of perineural invasion (p = 0.0042). Overall and disease-free survival were significantly higher for Group A than for Group C [hazard ratio (HR) = 4.32, 95% CI = 1.66-11.21, p = 0.0026 and HR=2.68, 95% CI = 1.33-5.40, p = 0.0057, respectively]. No significant difference was noted between Groups A and B for overall (p = 0.0591) or disease-free (p = 0.2834) survival. Another risk factor associated with recurrence and death was clinical T4 stage; nodal positivity was a risk factor only for recurrence.

CONCLUSION

Elevated CEA after neoadjuvant chemoradiation and clinical stage T4 disease were unfavourable predictors for overall and disease-free survival. Normalized CEA during neoadjuvant chemoradiation may serve as a prognosticator, although pretreatment CEA may significantly affect survival.

Impact of vaginal brachytherapy on survival in stage I endometrioid endometrial carcinoma

OBJECTIVE

To evaluate trends in use of radiation therapy and its impact on overall survival in low- and high-grade stage I endometrioid endometrial carcinoma.

METHODS

Patients with stage I endometrial cancer who underwent hysterectomy from 2004 to 2013 were identified through the National Cancer Database and classified as: stage IA G1/2, stage IA G3, stage IB G1/2, and stage IB G3. Trends in use of vaginal brachytherapy and external beam radiation therapy were assessed. Overall survival was measured from surgery and estimated using the Kaplan-Meier method. The effect of radiation therapy on overall survival was assessed within each stage/grade group using Cox proportional hazards analysis in propensity-matched treatment groups.

RESULTS

A total of 132 393 patients met inclusion criteria, and 81% of patients had stage IA and 19% had stage IB endometrial cancer. Adjuvant therapy was administered in 18% of patients: 52% received vaginal brachytherapy, 30% external beam radiation therapy, and 18% chemotherapy ±radiation therapy. External beam radiation therapy use decreased from 9% in 2004 to 4% in 2012, while vaginal brachytherapy use increased from 8% to 14%. Stage IA G1/2 patients did not benefit from either external beam radiation therapy or vaginal brachytherapy, while administration of vaginal brachytherapy improved overall survival in stage IB G1/2 compared with no treatment (p<0.0001). In stage IB G1/2 and stage IA G3, vaginal brachytherapy was superior to external beam radiation therapy (p=0.0004 and p=0.004, respectively). Stage IB G3 patients had improved overall survival with either vaginal brachytherapy or external beam radiation therapy versus no treatment but no difference in overall survival was seen between vaginal brachytherapy and external beam radiation therapy (p=0.94).

CONCLUSIONS

The delivery of adjuvant radiation therapy in patients with stage IA G1/2 endometrial carcinoma is not associated with improvement in overall survival. Patients with stage IB G1/2 and G3 as well as stage IA G3 are shown to benefit from improved overall survival when adjuvant radiation therapy is administered. These findings demonstrate potential opportunities to reduce both overtreatment and undertreatment in stage I endometrial cancer patients.

Undifferentiated endometrial carcinoma: a National Cancer Database analysis of prognostic factors and treatment outcomes

BACKGROUND

Undifferentiated endometrioid endometrial carcinoma of the uterus is a rare, highly aggressive, and under-recognized subtype of endometrial cancer.

OBJECTIVE

This study evaluates survival, prognostic factors for survival, and treatment outcomes associated with undifferentiated endometrial cancer.

METHODS

The National Cancer Database was queried to identify patients with undifferentiated endometrial cancer who underwent definitive primary surgical treatment. Patients with all other histologic subtypes or incomplete treatment data were excluded. Univariable and multivariable Cox proportional hazards analyses were used to determine independent prognostic factors for survival. Points for each prognostic factor were assigned from regression coefficients in the final multivariable model and summed for a total score. Recursive partitioning analysis was used to determine cut-offs in the score to identify unique prognostic groups.

RESULTS

Among 349 404 women diagnosed with endometrial cancer from 2004 to 2013, 3994 (1.1%) met the criteria for diagnosis of undifferentiated endometrial cancer and 3486 had survival data. Median age at diagnosis was 65 years (interquartile range (IQR) 57-74) and 58% of patients had early stage disease. Median interval from diagnosis to surgery was 3.7 weeks (IQR 2.0-5.7). Five year overall survival was 57% (standard error (SE) 1%). Stage was the strongest predictor of survival, with a 15-20% decrement in 5 year survival for each advance in stage. Stage, age, race, and presence of comorbidities were independent predictors of survival and were used to categorize patients into five prognostic groups. Adjuvant therapy was associated with improved survival across most disease stages and prognostic groups. Multimodal adjuvant therapy was superior to unimodal treatment particularly in advanced stage unfavorable and very unfavorable groups.

CONCLUSION

In women with undifferentiated endometrial cancer, survival is primarily driven by stage. Despite the poor overall prognosis of undifferentiated endometrial cancer, multimodal adjuvant therapy is a key component of treatment.

Oncological Outcomes of Patients with Locally Advanced Rectal Cancer and Lateral Pelvic Lymph Node Involvement

INTRODUCTION

The optimal management of patients with radiologically positive lateral pelvic lymph nodes in locally advanced rectal cancer remains unclear. We compared local recurrence rates and oncological outcomes of patients with locally advanced cancer with and without lateral pelvic lymph nodes.

METHODS

Patients who underwent curative surgery for stage III rectal adenocarcinoma between 2009 and 2014 and had a preoperative MRI at our institution as well as preoperative neoadjuvant treatment were included. Patients with positive lateral pelvic lymph nodes (iliac or obturator nodes) on preoperative MRI (LPND +) were compared to patients with no lateral pelvic nodal disease (LPND -). Data were collected from a prospectively maintained institutional database. Differences between the groups were compared in univariate analysis. Log-rank test was used to evaluate overall and disease-free survival between the groups.

RESULTS

A total of 125 patients met inclusion criteria with a mean age of 56.3 ± 12.2 and 75% were male. Median follow-up was 44 months (IQR 32, 106). Positive LPND was present on preoperative MRI in 43/125 (34.4%) patients who were in the LPND (+) group. Seventeen out of 43 patients had a post-neoadjuvant treatment MRI and 15 patients had a decrease in size of nodes or disappearance of LPND. On univariate analysis, LPND (+) and LPND (-) groups were comparable. Local recurrence rates were higher in the LPND (+) group, although this was not statistically significant (16.3% vs. 6%, p = 0.06). Overall and disease-free survival rates were comparable between the LPND (+) and LPND (-) groups (p = 0.97, p = 0.51).

CONCLUSIONS

Management of patients with advanced rectal cancer and radiologically positive lateral pelvic lymph nodes is challenging due to high local recurrence rates. Further studies are needed to develop care pathways for the optimal treatment processes.

Artificial sweeteners as a sugar substitute: Are they really safe?

Nonnutritive sweeteners (NNS) have become an important part of everyday life and are increasingly used nowadays in a variety of dietary and medicinal products. They provide fewer calories and far more intense sweetness than sugar-containing products and are used by a plethora of population subsets for varying objectives. Six of these agents (aspartame, saccharine, sucralose, neotame, acesulfame-K, and stevia) have previously received a generally recognized as safe status from the United States Food and Drug Administration, and two more (Swingle fruit extract and advantame) have been added in the recent years to this ever growing list. They are claimed to promote weight loss and deemed safe for consumption by diabetics; however, there is inconclusive evidence to support most of their uses and some recent studies even hint that these earlier established benefits regarding NNS use might not be true. There is a lack of properly designed randomized controlled studies to assess their efficacy in different populations, whereas observational studies often remain confounded due to reverse causality and often yield opposite findings. Pregnant and lactating women, children, diabetics, migraine, and epilepsy patients represent the susceptible population to the adverse effects of NNS-containing products and should use these products with utmost caution. The overall use of NNS remains controversial, and consumers should be amply informed about the potential risks of using them, based on current evidence-based dietary guidelines.

Effect of multidisciplinary tumor conference on clinical management of rectal cancer

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Background: Presentation of rectal cancer cases at a multidisciplinary tumor conference (MTC) is a required standard for the newly formed National Accreditation Program for Rectal Cancer. However, its impact on clinical decision-making remains incompletely defined. Our aim was to determine the frequency and manner in which MTC changed the management of patients with rectal cancer at a tertiary academic center. Methods: All rectal cancer cases presented at the weekly Colorectal Cancer MTC between July 2015 and June 2016 at a single institution were prospectively included. Patient demographics and clinical information were recorded. The presenting physician completed a uniform written questionnaire outlining their plan before and after the MTC discussion, and any changes in management as a result of the discussion. Imaging and pathology were reviewed for each case at MTC and consistency with prior interpretation was recorded. Results: 234 unique initial rectal cancer cases were included. Survey responses were obtained for 212 cases (90.6%). The mean patient age was 58.3 years. 37 patients (15.8%) presented with Stage IV disease and 20 (9.4%) had locally recurrent cancer. There was a documented change in plan as a result of the MTC discussion in 70 of 212 (33%) cases surveyed, including 22 cases (10.4%) in which the presenting physician had a “definitive plan” prior to the MTC. Changes in management included a change in therapy or change in therapy sequence in 45 cases (64%), and recommendation of further evaluation in 26 cases (37%). Change in management following MTC did not vary by surgeon experience: it occurred in 31.4%, 37.2% and 29.8% of cases presented by surgeons with < 10, 10-20, and ≥ 20 years of experience respectively (Chi-square p= 0.71). The imaging or pathology review at MTC resulted in a different interpretation than previously reported in 23% and 12% of cases, respectively. Conclusions: MTC changes clinical management for a significant portion of rectal cancer patients at a tertiary care center, independent of the presenting surgeons’ years of clinical experience. Our results highlight the utility of multidisciplinary rectal cancer care and support the MTC standard for the National Accreditation Program for Rectal Cancer.

The impact of combined radiation and chemotherapy on outcome in uterine papillary serous carcinoma compared to chemotherapy alone

OBJECTIVE

To investigate the impact of pelvic radiation on survival in patients with uterine serous carcinoma (USC) who received adjuvant chemotherapy.

METHODS

Patients with stage I-IV USC were identified from the Surveillance, Epidemiology, and End Results program 2000 to 2009. Patients were included if treated with surgery and chemotherapy. Patients were divided into two groups: those who received chemotherapy and pelvic radiation therapy (CT_RT) and those who received chemotherapy only (CT). Kaplan-Meier curves and Cox regression proportional hazard models were used.

RESULTS

Of the 1,838 included patients, 1,272 (69%) were CT and 566 (31%) were CT_RT. Adjuvant radiation was associated with significant improvement in overall survival (OS; p<0.001) and disease-specific survival (DSS; p<0.001) for entire cohort. These findings were consistent for the impact of radiation on OS (p<0.001) and DSS (p<0.001) in advanced stage (III-IV) disease but not for early stage (I?II) disease (p=0.21 for OS and p=0.82 for DSS). In multivariable analysis adjusting for age, stage, race and extent of lymphadenectomy, adjuvant radiation was a significant predictor of OS and DSS for entire cohort (p=0.003 and p=0.05) and in subset of patients with stage III (p=0.02 and p=0.07) but not for patients with stage I (p=0.59 and p=0.49), II (p=0.83 and p=0.82), and IV USC (p=0.50 and p=0.96). Other predictors were stage, positive cytology, African American race and extent of lymphadenectomy.

CONCLUSION

In USC patients who received adjuvant chemotherapy, adjuvant radiation was associated with significantly improved outcome in stage III disease but not for other stages. Positive cytology, extent of lymphadenectomy and African race were significant predictors of outcome.

Effects of the 2011 duty hour reforms on interns and their patients: a prospective longitudinal cohort study

IMPORTANCE

In 2003, the first phase of duty hour requirements for US residency programs recommended by the Accreditation Council for Graduate Medical Education (ACGME) was implemented. Evidence suggests that this first phase of duty hour requirements resulted in a modest improvement in resident well-being and patient safety. To build on these initial changes, the ACGME recommended a new set of duty hour requirements that took effect in July 2011.

OBJECTIVE

To determine the effects of the 2011 duty hour reforms on first-year residents (interns) and their patients.

DESIGN

As part of the Intern Health Study, we conducted a longitudinal cohort study comparing interns serving before (2009 and 2010) and interns serving after (2011) the implementation of the new duty hour requirements.

SETTING

Fifty-one residency programs at 14 university and community-based GME institutions.

PARTICIPANTS

A total of 2323 medical interns.

MAIN OUTCOME MEASURES

Self-reported duty hours, hours of sleep, depressive symptoms, well-being, and medical errors at 3, 6, 9, and 12 months of the internship year.

RESULTS

Fifty-eight percent of invited interns chose to participate in the study. Reported duty hours decreased from an average of 67.0 hours per week before the new rules to 64.3 hours per week after the new rules were instituted (P < .001). Despite the decrease in duty hours, there were no significant changes in hours slept (6.8 → 7.0; P = .17), depressive symptoms (5.8 → 5.7; P = .55) or well-being score (48.5 → 48.4; P = .86) reported by interns. With the new duty hour rules, the percentage of interns who reported concern about making a serious medical error increased from 19.9% to 23.3% (P = .007).

CONCLUSIONS AND RELEVANCE

Although interns report working fewer hours under the new duty hour restrictions, this decrease has not been accompanied by an increase in hours of sleep or an improvement in depressive symptoms or well-being but has been accompanied by an unanticipated increase in self-reported medical errors.

Dosimetric analysis of radiation-induced gastric bleeding

PURPOSE

Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy.

METHODS AND MATERIALS

The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of ≥grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models.

RESULTS

Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD₅₀ (normal) = 56 Gy and TD₅₀ (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD₅₀ value for the cirrhosis patients points out their greater sensitivity.

CONCLUSIONS

This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

Frequency, nature, effects, and correlates of conflicts of interest in published clinical cancer research

BACKGROUND

Relationships between clinical researchers and industry are becoming increasingly complex. The frequency and impact of conflicts of interest in the full range of high-impact, published clinical cancer research is unknown.

METHODS

The authors reviewed cancer research published in 8 journals in 2006 to determine frequency of self-reported conflicts of interest, source of study funding, and other characteristics. They assessed associations between the likelihood of conflicts of interest and other characteristics by using chi-squared testing. They also compared the likelihood of positive outcome in randomized trials with and without conflicts of interest by chi-squared testing.

RESULTS

The authors identified 1534 original oncology studies; 29% had conflicts of interest (including industrial funding) and 17% declared industrial funding. Conflicts of interest varied by discipline (P < .001), continental origin (P < .001), and sex (P < .001) of the corresponding author and were most likely in articles with corresponding authors from departments of medical oncology (45%), those from North America (33%), and those with male first and senior authors (37%). Frequency of conflicts also varied considerably depending upon disease site studied. Studies with industrial funding were more likely to focus on treatment (62% vs 36%; P < .001), and randomized trials that assessed survival were more likely to report positive survival outcomes when a conflict of interest was present (P = .04).

CONCLUSIONS

Conflicts of interest characterize a substantial minority of clinical cancer research published in high-impact journals. Therefore, attempts to disentangle the cancer research effort from industry merit further attention, and journals should embrace both rigorous standards of disclosure and heightened scrutiny when conflicts exist.

Phylogenetic conservation of the stem-loop III structure of the 5' untranslated region of Hepatitis C virus RNA among natural variants in samples collected from Southern India

The stem-loop III (SLIII) structure within the 5' untranslated region has been shown to be critical for internal initiation of translation of Hepatitis C virus (HCV). Using 'Single Strand Conformation Polymorphism (SSCP)' of the SLIII region we have investigated for natural mutations and demonstrated presence of some non-covariant changes in certain sub-domains. However, overall SLIII-RNA structure was found to be phylogenetically conserved. Additionally, by SSCP analysis we have determined the genotype of 50 HCV isolates collected from Southern India, 25 random samples were confirmed by DNA sequencing. Results showed the prevalence of genotype 1 in this part of India.