Correlation between surgical booking by a PA and surgical procedure performed.

OBJECTIVE: This study evaluated the concordance between clinical evaluation and diagnosis by a physician associate/assistant (PA) and the preoperative and intraoperative evaluations by a pediatric urologic surgeon. METHODS: A retrospective chart review was performed for patients independently evaluated and scheduled for surgery by a single PA between 2017 and 2020. Concordance was measured by comparing the PA's office note with the surgeon's preoperative note and operative report. RESULTS: Of the 242 patients scheduled for surgery, 11 underwent an operative report procedure change and 11 others underwent a preoperative note procedure change. Concordance increased from 89.09% in 2017 to 92.31% in 2020; this was not statistically significant ( P = .230). Urologic conditions evaluated demonstrated an increase in the variety and complexity of conditions. CONCLUSIONS: A supervisory/collaborative model involving a well-trained PA yields excellent outcomes in terms of concordance with surgical scheduling and procedure performed.

Prevalence and Predictors of Depression, Anxiety and Stress among Elderly during COVID-19: A Cross-sectional Study from Central India.

During the COVID-19 pandemic, elderly people have been more prone to depression, anxiety and stress. During these trying times, they require more attention and support for their mental health. This cross-sectional study was performed with the duration of 06 months from March 2021 to August 2021 in AIIMS, Bhopal in the state of Madhya Pradesh, in central India. And the participants recruited by systematic random sampling from a population aged more than 60 years, those who were able to read and write Hindi or English and having at least one family member; who reported to AIIMS, Bhopal during the second wave of COVID-19 in India. Those who were confirmed COVID-19 cases and undergoing treatment for the same, with diagnosed mental health disorders and who didn't give consent were excluded. A Google form based online semi-structured questionnaire along with DASS-21 scale was completed by participants. Elderly (>=60 years) will be selected. Of the 690 participants 7.25% reported mild to moderate depression, whereas 0.58 percent had severe or extremely severe depression. Mild to moderate anxiety were found in 9.56% of people, while 2.46% had severe or extremely severe anxiety. Mildly or moderately were stressed 4.78%, while 0.42% was severely or extremely anxious. Alcoholism and depression were found to have a statistically significant relationship (p=0.028). During the COVID-19 pandemic, elderly subjects who napped during the day were substantially less depressed (p=0.033). The older the respondents were, the more nervous they were during the pandemic (p=0.042). There is a link between alcohol consumption and stress (p=0.043) and it was seen that females were more stressed as compared to males (p=0.045). There was a strong correlation between participants' alcohol addiction and depressive symptoms. Psychological therapies for the elderly are thought to be necessary to enhance their psychological resilience and mental health. We need to tackle the stigma related to the COVID-19 and mental health issues.

An evaluation of race-based representation among men participating in clinical trials for prostate cancer and erectile dysfunction.

Background: Inclusion of ethnic/racial minorities in clinical trials is essential to fully assess therapeutic efficacy. It is well-known that populations respond dissimilarly to interventions. Our objective is to analyze the inclusion of minority men in clinical trials for erectile dysfunction (ED). Methods: We searched ClinicalTrials.gov for the disease keyword: "Erectile Dysfunction" and used "Prostate Cancer" for comparison. Completed trials which reported demographic data were included for analysis. Literature was reviewed to determine the prevalence of ED and prostate cancer (PC) among Hispanic, Black, White, and Asian men. The proportion of individuals of each group that participated in trials is divided by the proportion of each group in the disease population to calculate the "Participation to Prevalence Ratio" (PPR). PPRs between 0.8 and 1.2 indicates adequate representation, <0.8 is under-representation and >1.2 is over-representation. Results: A total of 312 trials were assessed: 289 for prostate cancer and 23 for ED. Hispanic men comprised 11.8% of ED trial participants and 4.6% of prostate cancer trial participants, yet represented 18% of ED patients and 7.3% of PC patients. Black/African-American (AA) men accounted for 10.2% of ED trial participants and 9.4% of PC trial participants, but comprise 16% of ED patients, and 16.3% of PC patients. Hispanic and AA men are under-represented in trials for ED and Prostate Cancer (Hispanic ED PPR = 0.66; Hispanic PC PPR = 0.63; AA ED PPR = 0.64; AA PC PPR = 0.58). Conclusion: Our analysis shows that both Hispanic and AA men are underrepresented in both ED and PC clinical trials.

Slow Frequency Anuloma Viloma Pranayama Modulates Cardiac and Neural Oscillations in Yoga Practitioners.

Anuloma viloma pranayama (AVP) also known as Alternate nostril breathing (ANB) is the most commonly used form of pranayama, the ancient breath control practice. It is known to modulate cardiovascular control and brain activity. This study analysed the simultaneous recording of Heart rate variability (HRV) and brain activity during and after AVP at a very slow frequency. We carried out an observational cohort study from October 2021 to December 2021 with purposive sample of 30 (Thirty) healthy volunteers involved in regular kriya yoga practice for the last 15 years were inducted into this study AVP involves slow and deep inhalation through one nostril at a time. The ECG for HRV analysis and spectrum of EEG waves were recorded throughout the pre-AVP, during-AVP and post-AVP (each of five-minute duration). The parameters were compared and analysed by repeated measures of analysis of variance with post-hoc analysis using Bonferroni and Holm's multiple comparisons. In time Domain parameters, SDNN and RMSSD were significantly higher during AVP as compared to the pre-AVP and post AVP. In frequency domain parameters total power, LF power, HF power, showed a significant increase during AVP, LF/HF ratio increased during AVP and remained higher post-AVP also. Similarly, Alpha, Beta and Gamma wave power increased significantly during AVP as compared to pre-AVP and post-AVP. The lungs-heart-brain act as coupled oscillators, the analysed data show an increased arousal, attentive and focused state with a negligible change in the heart rate. An overall increased variability in HRV was recorded.

Seeding metastases: The role and clinical utility of circulating tumour cells.

Peripheral human blood is a readily-accessible source of patient material in which circulating tumour cells (CTCs) can be found. Their isolation and characterization holds the potential to provide prognostic value for various solid cancers. Enumeration of CTCs from blood is becoming a common practice in informing prognosis and may guide therapy decisions. It is further recognized that enumeration alone does not capture perspective on the heterogeneity of tumours and varying functional abilities of the CTCs to interact with the secondary microenvironment. Characterizing the isolated CTCs further, in particular assessing their functional abilities, can track molecular changes in the disease progress. As a step towards identifying a suite of functional features of CTCs that could aid in clinical decisions, developing a CTC isolation technique based on extracellular matrix (ECM) interactions may provide a more solid foundation for isolating the cells of interest. Techniques based on size, charge, density, and single biomarkers are not sufficient as they underutilize other characteristics of cancer cells. The ability of cancer cells to interact with ECM proteins presents an opportunity to utilize their full character in capturing, and also allows assessment of the features that reveal how cells might behave at secondary sites during metastasis. This article will review some common techniques and recent advances in CTC capture technologies. It will further explore the heterogeneity of the CTC population, challenges they experience in their metastatic journey, and the advantages of utilizing an ECM-based platform for CTC capture. Lastly, we will discuss how tailored ECM approaches may present an optimal platform to capture an influential heterogeneous population of CTCs.

International round-robin experiment for angle-resolved light scattering measurement.

An international round-robin experiment has been conducted to test procedures and methods for the measurement of angle-resolved light scattering. ASTM E2387-05 has been used as the main guide, while the experience gained should also contribute to the new ISO standard of angle-resolved scattering currently under development (ISO/WD 19986:2016). Seven laboratories from Europe and the United States measured the angle-resolved scattering from Al/SiO2-coated substrates, transparent substrates, volume diffusors, quasi-volume diffusors, white calibration standards, and grating samples at laser wavelengths in the UV, VIS, and NIR spectra. Results were sent to Fraunhofer IOF, which coordinated the experiments and analyzed the data, while ESA-ESTEC, as the project donor, defined conditions and parameters. Depending mainly on the sample type, overall good to reasonable agreements were observed, with largest deviations at scattering angles very close to the specular beam. Volume diffusor characterization unexpectedly turned out to be challenging. Not all participants provided measurement uncertainty ranges according to the Guide to the Expression of Uncertainty in Measurement; often, a single general scatterometer-related measurement uncertainty value was stated. Although relative instrument measurement uncertainties close to 1% are sometimes claimed, the comparison results did not support these claims for specular scattering samples as mirrors, substrates, or gratings.

Interference Screw Versus Suture Endobutton Fixation of a Fiber-Reinforced Meniscus Replacement Device in a Human Cadaveric Knee Model.

BACKGROUND: Meniscal lesions represent one of the most common intra-articular knee injuries. Meniscus replacement devices are needed to restore load distribution and knee stability after meniscectomy. Fixation of these devices is crucial to the generation of hoop stresses and the distribution of loads in the joint. PURPOSE: To evaluate 2 different fixation techniques (suture endobutton and interference screw) for implantation of a novel meniscus device. STUDY DESIGN: Controlled laboratory study. METHODS: In 7 human cadaveric knees (aged 17-61 years), 1 anterior and 2 potential posterior tunnel locations were investigated, and both fixation techniques were tested in each tunnel. The native meniscus roots, devices fixed with a suture endobutton, and devices fixed with an interference screw were gripped with cryoclamps, and tibias were drilled and loaded into a custom jig. Samples were preloaded, preconditioned, loaded for 500 cycles (50-150 N), and tested in tension until failure. RESULTS: For all 3 tunnels, suture fixation resulted in greater elongation (54.1%-150.7% greater; P < .05) during cyclic loading than interference screw fixation, which approximated the native roots. Both fixation techniques displayed ultimate tensile loads in the same range as native roots. However, stiffness of the suture fixation groups (36.5-41.6 N/mm) was only 28% to 37% of that of the interference screw fixation groups (98.7-131.6 N/mm), which had values approaching those of the native roots (anterior: 175.4 ± 24.2 N/mm; posterior: 157.6 ± 22.9 N/mm). CONCLUSION: Interference screw fixation was found to be superior to suture fixation with regard to elongation and stiffness, a finding that should be considered in the design and implantation of novel meniscus replacement devices. CLINICAL RELEVANCE: With the emergence of various devices for total meniscus replacement, the establishment of fixation strategies is crucial for the generation of tensile hoop stresses and the efficacy of these approaches.

Immunomodulatory Peptide IDR-1018 Decreases Implant Infection and Preserves Osseointegration.

BACKGROUND: Innate defense regulator peptide-1018 (IDR-1018) is a 12-amino acid, synthetic, immunomodulatory host defense peptide that can reduce soft tissue infections and is less likely to induce bacterial resistance than conventional antibiotics. However, IDRs have not been tested on orthopaedic infections and the immunomodulatory effects of IDR-1018 have only been characterized in response to lipopolysacharide, which is exclusively produced by Gram-negative bacteria. QUESTIONS/PURPOSES: We sought (1) to more fully characterize the immunomodulatory effects of IDR-1018, especially in response to Staphylococcus aureus; and (2) to determine whether IDR-1018 decreases S aureus infection of orthopaedic implants in mice and thereby protects the implants from failure to osseointegrate. METHODS: In vitro effects of IDR-1018 on S aureus were assessed by determining minimum inhibitory concentrations in bacterial broth without and with supplementation of physiologic ion levels. In vitro effects of IDR-1018 on macrophages were determined by measuring production of monocyte chemoattractant protein-1 (MCP-1) and proinflammatory cytokines by enzyme-linked immunosorbent assay. In vivo effects of IDR-1018 were determined in a murine model of S aureus implant infection by quantitating bacterial burden, macrophage recruitment, MCP-1, proinflammatory cytokines, and osseointegration in nine mice per group on Day 1 postimplantation and 20 mice per group on Day 15 postimplantation. RESULTS: IDR-1018 demonstrated antimicrobial activity by directly killing S aureus even in the presence of physiologic ion levels, increasing recruitment of macrophages to the site of infections by 40% (p = 0.036) and accelerating S aureus clearance in vivo (p = 0.008) with a 2.6-fold decrease in bacterial bioburden on Day 7 postimplantation. In vitro immunomodulatory activity of IDR-1018 included inducing production of MCP-1 in the absence of other inflammatory stimuli and to potently blunt excess production of proinflammatory cytokines and MCP-1 induced by lipopolysaccharide. Higher concentrations of IDR-1018 were required to blunt production of proinflammatory cytokines and MCP-1 in the presence S aureus. The largest in vivo immunomodulatory effect of IDR-1018 was to reduce tumor necrosis factor-α levels induced by S aureus by 60% (p = 0.006). Most importantly, IDR-1018 reduced S aureus-induced failures of osseointegration by threefold (p = 0.022) and increased osseointegration as measured by ultimate force (5.4-fold, p = 0.033) and average stiffness (4.3-fold, p = 0.049). CONCLUSIONS: IDR-1018 is potentially useful to reduce orthopaedic infections by directly killing bacteria and by recruiting macrophages to the infection site. CLINICAL RELEVANCE: These findings make IDR-1018 an attractive candidate to explore in larger animal models to ascertain whether its effects in our in vitro and mouse experiments can be replicated in more clinically relevant settings.

Synthesis, antimicrobial and anticancer evaluation of N'-(substituted benzylidene)-2-(benzo[d]oxazol-3(2H)-yl)acetohydrazide derivatives.

A series of N'-(substituted benzylidene)-2-(benzo[d]oxazol-3(2H)-yl)acetohydrazide derivatives was synthesized and evaluated for its in vitro antimicrobial and anticancer activities. Antimicrobial activity results revealed that compound 12 was found to be the most potent antimicrobial agent. Results of anticancer study indicated that the synthesized compounds exhibited average anticancer potential. Compound 7 (IC 50 =3.12 µM) and compound 16 (IC 50 =2.88 µM) were found to be most potent against breast cancer (MCF7) cell lines. In conclusion, compound 12 and 16 have the potential to be selected as lead compound for the developing of novel antimicrobial and anticancer agents respectively.

The fallopian canal: a comprehensive review and proposal of a new classification.

INTRODUCTION: The facial nerve follows a complex course through the skull base. Understanding its anatomy is crucial during standard skull base approaches and resection of certain skull base tumors closely related to the nerve, especially, tumors at the cerebellopontine angle. METHODS: Herein, we review the fallopian canal and its implications in surgical approaches to the skull base. Furthermore, we suggest a new classification. CONCLUSIONS: Based on the anatomy and literature, we propose that the meatal segment of the facial nerve be included as a component of the fallopian canal. A comprehensive knowledge of the course of the facial nerve is important to those who treat patients with pathology of or near this cranial nerve.

Minimum light intensity threshold to prevent negative effects on broiler production and welfare.

1. Research focused on lower light intensity levels is required to set minimum standards appropriate for production and welfare of intensively housed broilers. The objective of this research was to study light intensity (0.1 to 10 lx) effects on Ross × Ross 308 and 708 genotypes. 2. Three experiments (35 d each) using 18 720 broilers were conducted with the initial experiment using two replicates of 0.1, 1, 5 and 10 lx. The second and third experiments examined 0.5, 1, 5 and 10 lx with treatments replicated twice in each experiment in a randomised complete block design with experiment acting as a block. In each experiment, mixed sex broilers from each genotype were housed in 6 equally sized pens per room. 3. In Experiment 1, the introduction of 0.1 lx at d 7 caused high levels of mortality and poor growth rate from d 7 to 14 and was discontinued. 4. In Experiments 2 and 3, increasing light intensity increased body weight gain (0-35 d) and feed intake (0-35 d) in a quadratic and linear fashion, respectively. Similarly, mortality corrected gain to feed ratio (FCR, 0-35 d) demonstrated a quadratic response with a maximum at 5 lx. Carcass, breast meat and skin, abdominal fat and drum skin, as a percentage of live weight, increased while drum bone and wing yield decreased in a linear fashion with increasing light intensity. Total carcass composition was unaffected by light intensity. 5. Genotype effects were numerous. No interactions were found between genotype and light intensity. 6. Ocular dimensions and the incidence of foot pad lesions decreased in a quadratic and linear fashion, respectively, with increasing light intensity. In contrast, welfare-associated gait score and mortality levels were not affected by light intensity. 7. It was concluded that performance, breast meat yield and bird welfare improved with increasing light intensity. The data support 5 lx as a minimum light intensity in broiler production.

Characteristics of falls in the epilepsy monitoring unit: a retrospective study.

Falls are an important adverse event in an epilepsy monitoring unit (EMU). We identified patterns of falls in an EMU and compared them with risk factors for inpatient falls. Twenty-six patients with 26 falls (2.3% of admissions) in the EMU were compared with 50 general neurology inpatients with 56 falls over a 4-year period. In the EMU, the majority (62%) of falls happened during the first 3 days of admission, mostly in the bathroom (74%), in patients with a normal mental status (77%). Most general inpatients fell after the third day (64%), inside their rooms (68%), and had an altered mental status before the fall (68%). All 26 EMU patients were identified as high risk at admission, in spite of which falls were not prevented. We outline these differences between EMU patients and general inpatients and highlight the practice gap in preventing falls in an EMU.

Progressive limb ataxia following inferior olive lesions.

Cerebellar climbing fibres originate in the inferior olive (IO). Temporary IO inactivation produces movement deficits. Does permanent inactivation produce similar deficits and, if so, do they recover? The excitotoxin, kainic acid, was injected into the rostral IO of three cats. Behaviour was measured during reaching and locomotion. Two cats were injected during the reaching task. Within minutes, grasping became difficult and the trajectories of the reaches showed higher arcing than normally seen. During locomotion, both cats showed head and trunk deviation to the injected side, walking paths curved to the injected side, and the paws were lifted higher than normal. Limbs contralateral to the injections became rigid. Within 1 day, posture had normalized, locomotion was unsteady and high lifting of the paws had reversed to a tendency to drag the dorsum of the paws. Passive body movement produced vestibular signs. Over a few days, locomotion normalized and vestibular signs disappeared. Reach trajectories were normal but grasping deficits persisted. Over the first week, the amplitude of limb lift during reaching and locomotion began to increase. The increase continued over time and, after several months, limb movements became severely ataxic. The effects followed the somatotopy of the rostral IO: a loss of cells in medial rostral IO only affected the forelimb, whereas a loss of cells in medial and lateral IO affected both forelimb and hindlimb. Deficits produced by IO lesions involve multiple mechanisms; some recover rapidly, some appear stable, and some worsen over time. The nature of the progressive deficit suggests a gradual loss of Purkinje cell inhibition on cerebellar nuclear cells.

Gabriele Fallopio (1523-1562) and his contributions to the development of medicine and anatomy.

INTRODUCTION: Gabriele Fallopio was one of the greatest anatomists of the sixteenth century. He discovered and named numerous parts of the human body. His name survives to this day as it is associated with several anatomical structures including the Fallopian canal, Fallopian hiatus, Fallopian valve, Fallopian muscle, and the Fallopian tube. CONCLUSIONS: Our current knowledge of human anatomy is based on giants such as Fallopio. His contributions to neuroanatomy laid the foundations for the development of this discipline.

Stereotactic radiosurgery of cranial nonvestibular schwannomas: results of single- and multisession radiosurgery.

BACKGROUND: Surgical resection of nonvestibular cranial schwannomas carries a considerable risk of postoperative complications. Stereotactic radiosurgery (SRS) offers a non-invasive treatment alternative. The efficacy and safety of multi-session SRS of nonvestibular cranial schwannomas has not been well studied. OBJECTIVE: To analyze the results of single- and multi-session SRS of nonvestibular cranial schwannomas. METHODS: From 2001 to 2007, 42 lesions in 40 patients were treated with SRS at Stanford University Medical Center, targeting schwannomas of cranial nerves IV (n = 1), V (n = 18), VII (n = 6), X (n = 5), XII (n = 2), jugular foramen (n = 8), and cavernous sinus (n = 2). SRS was delivered to a median marginal dose of 18 Gy (range, 15-33 Gy) in 1 to 3 sessions, targeting a median tumor volume of 3.2 cm (range, 0.1-23.7 cm). The median doses for treatments in 1 (n = 18), 2 (n = 9), and 3 (n = 15) sessions were 17.5, 20, and 18 Gy, respectively. RESULTS: With a median follow-up of 29 months (range, 6-84 months), tumor control was achieved in 41 of the 42 lesions. Eighteen of 42 lesions (43%) decreased in size; 23 tumors (55%) remained stable. There were 2 cases of new or worsening cranial nerve deficits in patients treated in single session; no patient treated with multi-session SRS experienced any cranial nerve toxicity (P = 0.18). CONCLUSION: SRS of nonvestibular cranial schwannomas provides excellent tumor control with minimal risk of complications. There was a trend towards decreased complications with multi-session SRS.

Effect of light intensity on broiler production, processing characteristics, and welfare.

Manipulation of light intensity is an important management tool affecting broiler production and well being. Despite considerable research on light intensity, there is still a debate on the optimum level to be used for intensively housed broilers. Two trials were conducted with the objective of investigating the effect of light intensity, within the practical levels at confinement barns (1, 10, 20, and 40 lx), on production, processing characteristics, and welfare of broilers raised to 35 d of age. Each light intensity treatment was replicated in 2 environmentally controlled rooms in each trial with 950 Ross × Ross 308 chicks per room. Data were analyzed as a randomized complete block design with trial serving as a block. All chicks were exposed to 40 lx of light intensity and 23 h of light for the first 7 d followed by treatment light intensity and 17 h of day length thereafter. Body weight and feed consumption were determined at 7, 14, and 35 d of age. At the end of each trial, 60 birds per treatment were processed to determine the detailed meat yield. Skeletal and footpad and ocular health were monitored at 31 and 32 d of age, respectively. Body weight, feed consumption, feed:gain ratio, and mortality were unaffected by light intensity. Carcass, thigh, and drum yield as a percentage of live weight decreased linearly with increasing light intensity. The 1 lx treatment resulted in heavier wings as a percentage of live weight. Light intensity had no effect on skeletal health, but ulcerative footpad lesions decreased linearly with increasing light intensity. Birds exposed to the 1 lx treatment had heavier and larger eyes. In conclusion, light intensity did not affect broiler production and mortality but did affect carcass characteristics. The 1 lx light intensity treatment had a negative effect on broiler welfare as demonstrated by increased ulcerative footpad lesions and eye size.

Efficacy of 99mTc-DTPA lung clearance test in the diagnosis of PCP in HIV-positive patients.

The study aims to evaluate the efficacy of technetium-99m diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) lung clearance test in the diagnosis of pneumocystis carinii pneumonia (PCP) in HIV-positive paediatric patients. Twenty HIV-negative patients with no chest symptoms constituted Group A, 25 HIV antibody positive asymptomatic children formed Group B, while 45 HIV antibody positive children with respiratory infections comprised Group C. Group C was subdivided into C(1) (n = 20, documented PCP on microbiology), C(2) (n = 10, tuberculosis) and C(3) (n = 15, bacterial pneumonias). The mean age group of patients in Group A, Group B and Group C was 4.7 +/- 1.9, 4.2 +/- 1.5 and 4.8 +/- 1.7 years, respectively. All patients were subjected to complete blood count, blood culture, chest radiographs, microscopic staining of sputum (PCP stains, Ziehl-Nielsen staining, Gram staining), ABG and Mantoux test. All these patients underwent dynamic lung scans using (99m)Tc-DTPA aerosols and lung clearance was calculated in terms of half-time transfer value (T(1/2)) value. T(1/2) was compared between different groups and lung scan findings were correlated with radiological and microbiological results. Patients with PCP had T(1/2) in the range of 9.02 +/- 1.35, TB 28.2 +/- 3.03 min and other bacterial pneumonias in the range of 20.5 +/- 3.1 min (range for normal individuals was 49.8 +/- 6.13 min). T(1/2) in patients with PCP was found to be significantly lower when compared with T(1/2) in other groups. Patients with PCP had characteristic biphasic curves while the rest had monophasic curves. Some patients with PCP had low T(1/2) values even when chest radiographs and arterial blood gases were normal. (99m)Tc-DTPA lung clearance test is a sensitive, safe and non-invasive diagnostic tool for the early detection of PCP in HIV-positive paediatric patients.

An insight into the Leishmania RNA virus.

Leishmania RNA virus is an ancient virus that has coevolved with its protozoan host. The purpose of this article is to convey current understanding of Leishmania RNA virus as it has emerged over the past decade. The potential of the virus to play a role in modulating parasite virulence is also discussed.

Impact of integrated PET/CT on variability of target volume delineation in rectal cancer.

Several studies have demonstrated substantial variability among individual radiation oncologists in defining target volumes using computed tomography (CT). The objective of this study was to determine the impact of combined positron emission tomography and computed tomography (PET/CT) on inter-observer variability of target volume delineation in rectal cancer. We also compared the relative concordance of two PET imaging tracers, 18F-fluorodeoxyglucose (FDG) and 18F-fluorodeoxythymidine (FLT), against conventional computed tomography (CT). Six consecutive patients with locally advanced rectal cancer were enrolled onto an institutional protocol involving preoperative chemoradiotherapy and correlative studies including FDG- and FLT-PET scans acquired in the treatment position. Using these image data sets, four radiation oncologists independently delineated primary and nodal gross tumor volumes (GTVp and GTVn) for a hypothetical boost treatment. Contours were first defined based on CT alone with observers blinded to the PET images, then based on combined PET/CT. An inter-observer similarity index (SI), ranging from a value of 0 for complete disagreement to 1 for complete agreement of contoured voxels, was calculated for each set of volumes. For primary gross tumor volume (GTVp), the difference in estimated SI between CT and FDG was modest (CT SI = 0.77 vs. FDG SI = 0.81), but statistically significant (p = 0.013). The SI difference between CT and FLT for GTVp was also slight (FLT SI = 0.80) and marginally non-significant (p < 0.082). For nodal gross tumor volume, (GTVn), SI was significantly lower for CT based volumes with an estimated SI of 0.22 compared to an estimated SI of 0.70 for FDG-PET/CT (p < 0.0001) and an estimated SI of 0.70 for FLT-PET/CT (p < 0.0001). Boost target volumes in rectal cancer based on combined PET/CT results in lower inter-observer variability compared with CT alone, particularly for nodal disease. The use of FDG and FLT did not appear to be different from this perspective.