Core Challenges of Social Robot Navigation: A Survey

Robot navigation in crowded public spaces is a complex task that requires addressing a variety of engineering and human factors challenges. These challenges have motivated a great amount of research resulting in important developments for the fields of robotics and human-robot interaction over the past three decades. Despite the significant progress and the massive recent interest, we observe a number of significant remaining challenges that prohibit the seamless deployment of autonomous robots in crowded environments. In this survey article, we organize existing challenges into a set of categories related to broader open problems in robot planning, behavior design, and evaluation methodologies. Within these categories, we review past work, and offer directions for future research. Our work builds upon and extends earlier survey efforts by a) taking a critical perspective and diagnosing fundamental limitations of adopted practices in the field and b) offering constructive feedback and ideas that could inspire research in the field over the coming decade.

Metrics for Robot Proficiency Self-Assessment and Communication of Proficiency in Human-Robot Teams

As development of robots with the ability to self-assess their proficiency for accomplishing tasks continues to grow, metrics are needed to evaluate the characteristics and performance of these robot systems and their interactions with humans. This proficiency-based human-robot interaction (HRI) use case can occur before, during, or after the performance of a task. This paper presents a set of metrics for this use case, driven by a four stage cyclical interaction flow: 1) robot self-assessment of proficiency (RSA), 2) robot communication of proficiency to the human (RCP), 3) human understanding of proficiency (HUP), and 4) robot perception of the human’s intentions, values, and assessments (RPH). This effort leverages work from related fields including explainability, transparency, and introspection, by repurposing metrics under the context of proficiency self-assessment. Considerations for temporal level ( a priori , in situ , and post hoc ) on the metrics are reviewed, as are the connections between metrics within or across stages in the proficiency-based interaction flow. This paper provides a common framework and language for metrics to enhance the development and measurement of HRI in the field of proficiency self-assessment.

SocNavBench: A Grounded Simulation Testing Framework for Evaluating Social Navigation

The human-robot interaction (HRI) community has developed many methods for robots to navigate safely and socially alongside humans. However, experimental procedures to evaluate these works are usually constructed on a per-method basis. Such disparate evaluations make it difficult to compare the performance of such methods across the literature. To bridge this gap, we introduce SocNavBench , a simulation framework for evaluating social navigation algorithms. SocNavBench comprises a simulator with photo-realistic capabilities and curated social navigation scenarios grounded in real-world pedestrian data. We also provide an implementation of a suite of metrics to quantify the performance of navigation algorithms on these scenarios. Altogether, SocNavBench provides a test framework for evaluating disparate social navigation methods in a consistent and interpretable manner. To illustrate its use, we demonstrate testing three existing social navigation methods and a baseline method on SocNavBench , showing how the suite of metrics helps infer their performance trade-offs. Our code is open-source, allowing the addition of new scenarios and metrics by the community to help evolve SocNavBench to reflect advancements in our understanding of social navigation.

Isothermal relaxation kinetics for the reduction and oxidation of SrFeO3 based perovskites

The perovskite oxide SrFeO₃ has favourable redox properties for oxygen exchange applications, including oxygen separation and oxygen production chemical looping cycles. For such applications, lower temperature operation can improve the energy demand and feasibility of the process, but can also lead to kinetic limitations. Here we investigate the oxidation and reduction reaction kinetics of SrFeO₃ in the temperature range 450-750 K. Isothermal relaxation techniques are used to observe the reaction rates across this temperature range, using a thermogravimetric analysis system. Experimental data are analysed according to an isoconversional method and fit with a simple power law model to extract activation energies. The apparent activation energy of oxidation and reduction was found to be 92 ± 16 and 144 ± 17 kJ mol^-1 respectively. Comparison of oxidation and reduction kinetics together with considerations of particle size indicate that the oxidation reaction rate may be limited by diffusion in the bulk, while the reduction reaction rate is limited by the surface reaction. Furthermore, we also investigated the mixed perovskite Sr_0.93Ca_0.07Fe_0.9Co_0.1O₃, which exhibited a 4-fold increase in the oxidation rate.

High redox performance of Y0.5Ba0.5CoO3−δ for thermochemical oxygen production and separation

The efficient production and separation of oxygen is essential for numerous energy-intensive industrial applications in the fuel and mineral processing sectors.

Bakterienisolate aus dem unteren Respirationstrakt von erkrankten Hunden und deren aktuelle Resistenzsituation

Gegenstand: Retrospektive Untersuchung der mittels bronchoalveolärer Lavage (BAL) gewonnenen Keimflora der tiefen Atemwege erkrankter Hunde auf ihre Antibiotikaempfindlichkeit über 5 Jahre.

Material und Methoden: Auswertung der Ergebnisse der Agardiffusionstests von Bakterienisolaten, die in den Jahren 2004–2009 von 84 Hunden isoliert wurden, und Vergleich mit den Resultaten einer gleichartigen Analyse der Jahre 1999/2000.

Ergebnisse: Bei den 99 geprüften Bakterienisolaten handelte es sich um Pasteurella spp. (27,3%), Bordetella bronchiseptica (20,2%), Staphylococcus spp. (18,2%), Escherichia coli (15,2%), Klebsiella spp. (8,1%), Pseudomonas spp. (7,0%) und Streptococcus spp. (4,0%). Bei acht Hunden lagen Mischkulturen vor. Die Mehrzahl der Bordetella-(B.-)bronchiseptica-Isolate erwies sich als sensibel gegenüber den Fluorchinolonen sowie Tetracyclin, Doxycyclin und Polymyxin B. Im Vergleich zu 1999/2000 zeigte sich ein höherer Anteil der gegenüber Amoxicillin/Clavulansäure und Chloramphenicol empfindlichen B.-bronchiseptica-Isolate, wobei die Zunahme bezüglich Chloramphenicol statistisch signifikant war. Die überwiegende Anzahl der Staphylococcus-Isolate erwies sich gegenüber Enrofloxacin, Marbofloxacin, Amoxicillin/Clavulansäure, Chloramphenicol, Cephalexin, Doxycyclin und Polymyxin B sensibel. Im Vergleich zu 1999/2000 ergab sich ein erhöhter Anteil an Chloramphenicolund Tetracyclin-sensiblen Staphylococcus-Isolaten. Der Anteil Enrofloxacin-sensibler KlebsiellenIsolate betrug 62,5%, während er 1999/2000 bei 100% lag. Eine Sensibilität aller getesteten Klebsiellen-Isolate ließ sich noch gegenüber Polymyxin B nachweisen. Kein Antibiotikum zeigte eine Wirksamkeit gegenüber allen E.-coli-Isolaten. Statistisch signifikant war die Abnahme der gegenüber Amoxicillin/Clavulansäure-sensiblen Isolate.

Schlussfolgerung und klinische Relevanz: Die Studie unterstreicht den Nutzen der BAL für eine ätiologische Diagnostik und den anschließenden fundierten Einsatz von Antibiotika. Die Mehrzahl der Bakterienisolate erwies sich als empfindlich gegenüber den Fluorchinolonen.

How a diverse research ecosystem has generated new rehabilitation technologies: Review of NIDILRR's Rehabilitation Engineering Research Centers

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a "total approach to rehabilitation", combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970's, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program.

High Redox Capacity of Al-Doped La1-x Srx MnO3-δ Perovskites for Splitting CO2 and H2 O at Mn-Enriched Surfaces

Perovskites are attractive candidates for the solar-driven thermochemical redox splitting of CO₂ and H₂ O into CO and H₂ (syngas) and O₂ . This work investigates the surface activity of La_1-x Sr_x Mn_1-y Al_y O_3-δ (0≤x≤1, 0≤y≤1) and La_0.6 Ca_0.4 Mn_0.6 Al_0.4 O_3-δ . At 1623 K and 15 mbar O₂ , the oxygen non-stoichiometry of La_0.2 Sr_0.8 Mn_0.8 Al_0.2 O_3-δ increases with the strontium content and reaches a maximum of δ=0.351. X-ray photoelectron spectroscopy analysis indicates that manganese is the only redox-active metal at the surface. All La_1-x Sr_x Mn_1-y Al_y O_3-δ compositions exhibit surfaces enriched in manganese and depleted in strontium. We discuss how these compositional differences of the surface from the bulk lead to the beneficially higher reduction extents and lower strontium carbonate concentrations at the aluminum-doped surfaces. Using first principles calculations, we validate the experimental reduction trends and elucidate the mechanism of the partial electronic charge redistribution upon perovskite reduction.

Splitting CO2 with a ceria-based redox cycle in a solar-driven thermogravimetric analyzer

Thermochemical splitting of CO₂ via a ceria-based redox cycle was performed in a solar-driven thermogravimetric analyzer. Overall reaction rates, including heat and mass transport, were determined under concentrated irradiation mimicking realistic operation of solar reactors. Reticulated porous ceramic (RPC) structures and fibers made of undoped and Zr⁴⁺-doped CeO₂, were endothermally reduced under radiative fluxes of 1280 suns in the temperature range 1200-1950 K and subsequently re-oxidized with CO₂ at 950-1400 K. Rapid and uniform heating was observed for 8 ppi ceria RPC with mm-sized porosity due to its low optical thickness and volumetric radiative absorption, while ceria fibers with μm-sized porosity performed poorly due to its opacity to incident irradiation. The 10 ppi RPC exhibited higher fuel yield because of its higher sample density. Zr⁴⁺-doped ceria showed increasing reduction extents with dopant concentration but decreasing specific CO yield due to unfavorable oxidation thermodynamics and slower kinetics.

Tunable thermodynamic activity of La x Sr1-x Mn y Al1-y O3-δ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) perovskites for solar thermochemical fuel synthesis

Nonstoichiometric metal oxides with variable valence are attractive redox materials for thermochemical and electrochemical fuel processing. To guide the design of advanced redox materials for solar-driven splitting of CO₂ and/or H₂O to produce CO and/or H₂ (syngas), we investigate the equilibrium thermodynamics of the La _x Sr_1-x Mn _y Al_1-y O_3-δ perovskite family (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and La_0.6Ca_0.4Mn_0.8Al_0.2O_3-δ , and compare them to those of CeO₂ as the baseline. Oxygen nonstoichiometry measurements from 1573 to 1773 K and from 0.206 to 180 mbar O₂ show a tunable reduction extent, increasing with increasing Sr content. Maximal nonstoichiometry of 0.32 is established with La_0.2Sr_0.8Mn_0.8Al_0.2O_3-δ at 1773 K and 2.37 mbar O₂. As a trend, we find that oxygen capacities are most sensitive to the A-cation composition. Partial molar enthalpy, entropy and Gibbs free energy changes for oxide reduction are extracted from the experimental data using defect models for Mn⁴⁺/Mn³⁺ and Mn³⁺/Mn²⁺ redox couples. We find that perovskites exhibit typically decreasing enthalpy changes with increasing nonstoichiometries. This desirable characteristic is most pronounced by La_0.6Sr_0.4Mn_0.4Al_0.6O_3-δ , rendering it attractive for CO₂ and H₂O splitting. Generally, perovskites show lower enthalpy and entropy changes than ceria, resulting in more favorable reduction but less favorable oxidation equilibria. The energy penalties due to larger temperature swings and excess oxidants are discussed in particular. Using electronic structure theory, we conclude with a practical methodology estimating thermodynamic activity to rationally design perovskites with variable stoichiometry and valence.

Investigating the Heart Pump Implant Decision Process: Opportunities for Decision Support Tools to Help

Clinical decision support tools (DSTs) are computational systems that aid healthcare decision-making. While effective in labs, almost all these systems failed when they moved into clinical practice. Healthcare researchers speculated it is most likely due to a lack of user-centered HCI considerations in the design of these systems. This paper describes a field study investigating how clinicians make a heart pump implant decision with a focus on how to best integrate an intelligent DST into their work process. Our findings reveal a lack of perceived need for and trust of machine intelligence, as well as many barriers to computer use at the point of clinical decision-making. These findings suggest an alternative perspective to the traditional use models, in which clinicians engage with DSTs at the point of making a decision. We identify situations across patients' healthcare trajectories when decision supports would help, and we discuss new forms it might take in these situations.

Oxygen nonstoichiometry and thermodynamic characterization of Zr doped ceria in the 1573-1773 K temperature range

The thermodynamics and defect chemistry of Zr⁴⁺-doped ceria is investigated and discussed in regards to the efficiency of solar thermochemical redox cycles.

This work encompasses the thermodynamic characterization and critical evaluation of Zr⁴⁺ doped ceria, a promising redox material for the two-step solar thermochemical splitting of H₂O and CO₂ to H₂ and CO. As a case study, we experimentally examine 5 mol% Zr⁴⁺ doped ceria and present oxygen nonstoichiometry measurements at elevated temperatures ranging from 1573 K to 1773 K and oxygen partial pressures ranging from 4.50 × 10^–3 atm to 2.3 × 10^–4 atm, yielding higher reduction extents compared to those of pure ceria under all conditions investigated, especially at the lower temperature range and at higher p_O2. In contrast to pure ceria, a simple ideal solution model accounting for the formation of isolated oxygen vacancies and localized electrons accurately describes the defect chemistry. Thermodynamic properties are determined, namely: partial molar enthalpy, entropy, and Gibbs free energy. In general, partial molar enthalpy and entropy values of Zr⁴⁺ doped ceria are lower. The equilibrium hydrogen yields are subsequently extracted as a function of the redox conditions for dopant concentrations as high as 20%. Although reduction extents increase greatly with dopant concentration, the oxidation of Zr⁴⁺ doped ceria is thermodynamically less favorable compared to pure ceria. This leads to substantially larger temperature swings between reduction and oxidation steps, ultimately resulting in lower theoretical solar energy conversion efficiencies compared to ceria under most conditions. In effect, these results point to the importance of considering oxidation thermodynamics in addition to reduction when screening potential redox materials.

Physico-chemical changes in Ca, Sr and Al-doped La–Mn–O perovskites upon thermochemical splitting of CO2via redox cycling

Thermochemical CO₂-splitting via redox cycling of Ca, Sr and Al-doped La–Mn perovskites induces irreversible changes in the texture and chemical composition of these oxides.

[Bacterial susceptibility testings of the lower airways of diseased dogs]

OBJECTIVE

In this retrospective study over 5 years the bacterial flora of the deep airways of diseased dogs was sampled using bronchioalveolar lavage and its in-vitro susceptibility to numerous antimicrobial agents was analysed.

MATERIAL AND METHODS

Susceptibility testing of bacterial isolates from 84 dogs performed from 2004 to 2009 were evaluated and compared to data collected in 1999/2000.

RESULTS

The 99 bacterial isolates comprised Pasteurella spp. (27.3%), Bordetella bronchiseptica (20.2%), Staphylococcus spp. (18.2%), Escherichia coli (15.2%), Klebsiella spp. (8.1%), Pseudomonas spp. (7.0%), and Streptococcus spp. (4.0%). Lavage samples of eight dogs revealed simultaneous occurrence of more than one species. The majority of the tested Bordetella bronchiseptica-isolates were susceptible to fluoroquinolones as well as tetracycline, doxycycline and polymyxin B. The number of amoxicillin/clavulanic acid- and chloramphenicol-resistant isolates decreased compared to 1999/2000. The increase of chloramphenicol-susceptible isolates was statistically significant. The tested Staphylococcus-isolates revealed a susceptibility to fluoroquinolones, amoxicillin, cephalexin, doxycycline, and polymyxin B. Compared to the earlier study, a major portion exhibited susceptibility to chloramphenicol and tetracycline. None of the Klebsiella spp. tested in 1999/2000 was resistant to enrofloxacin, whereas only 62.5% of the isolates examined during 2004-2009 were susceptible. A susceptibility of all tested Klebsiella -isolates was detectable with respect to polymyxin B. Regarding E.coli , none of the tested antibiotics revealed an in-vitro activity against all of the tested isolates. The increase of amoxicillin/clavulanic acid-resistant isolates was statistically significant.

CONCLUSION AND CLINICAL RELEVANCE

The study demonstrates the benefits of bronchioalveolar lavage as a diagnostic tool to ensure a responsible utilisation of antibiotics. Most of the tested bacterial isolates were susceptible to fluoroquinolones.

[Evaluation of the need for communication training of ophthalmologists for gaining telephone consent for cornea donation]

INTRODUCTION

Because of the gap between the high need for cornea tissue for transplantation and the current lower numbers of donors, there is high pressure to succeed in telephone calls to relatives of deceased for obtaining consent. Besides the attempt to increase the rate of donors, these telephone calls should be gentle for relatives and not overstrain professionals. This study assesses the need and expectations of physicians towards communication training in preparation for their task.

METHODS

In September-October 2009 a needs assessment for communication training among physicians who currently work or have worked for the eye bank took place. Personal data were recorded and their estimate of the perceived burden as well as needs and potential benefits from a specific communication training for obtaining consent for cornea donation by telephone were assessed using numeric rating scales between 1 (minimum) and 10 (maximum). Results were expressed as mean and range.

RESULTS

The participants felt only moderately prepared for the task regarding information content, their emotions and personal convictions. They considered a specific training to be highly meaningful, necessary and helpful. Their highest burden during telephone calls previously experienced was documented as 8.4 and the average burden as 6.3. Accordingly, their willingness to continue working at an eye bank after their rotation was moderate.

DISCUSSION

Physicians involved in obtaining consent for cornea donation by telephone feel highly stressed and only moderately prepared for fulfilling the task both for the information content and on the emotional level. Accordingly, specific communication training is perceived as highly meaningful, necessary and helpful. An educational program was developed to meet the needs and expectations of physicians.

The Design and Evaluation of User Interfaces for the RADAR Learning Personal Assistant

The RADAR project developed a large multi-agent system with a mixed-initiative user interface designed to help office workers cope with email overload. Most RADAR agents observe experts performing tasks and then assist other users who are performing similar tasks. The interaction design for RADAR focused on developing user interfaces that allowed the intelligent functionality to improve the user’s workflow without frustrating the user when the system’s suggestions were either unhelpful or simply incorrect. For example with regards to autonomy, the RADAR agents were allowed much flexibility in selecting ways to assist the user, but were restricted from taking actions that would be visible to other people. This policy ensured that the user remained in control and mitigated the negative effects of mistakes. A large evaluation of RADAR demonstrated that novice users confronted with an email overload test performed significantly better, achieving a 37% better overall score when assisted by RADAR. The evaluation showed that AI technologies can help users accomplish their goals.

Bioavailability of fluorescein from a new drug delivery system in human eyes

AIM

To assess the ocular bioavailability of fluorescein from a novel drug delivery system compared with one single preservative free eye drop.

METHODS

Part A: In a randomised study 10 volunteers applied the lyophilisate to one eye and a conventional fluorescein eye drop to the fellow eye. Fluorophotometry was performed before and every 2 minutes up to 30 minutes after application in the cornea and anterior chamber. Part B: Another 10 volunteers applied each form of the application. Fluorophotometry was performed before, +2 minutes, and at +8, +10, +12 hours. The dose corresponding to a single fluorescein dose of the lyophilisate was 68 l microg fluorescein SE 0.17%.

RESULTS

Part A: During the first 30 minutes after administration of the preservative free eye drop of 40 microg the corneal and anterior chamber concentration means were up to 16 times higher in eyes treated with the lyophilisate. Part B: 8-12 hours after application the mean fluorescein concentration in the cornea of the lyophilisate group was two times higher than at baseline. Eyes treated with eye drops had baseline values at +8, +10 and +12 hours.

CONCLUSION

A significantly better bioavailability was achieved in human eyes by using lyophilisate compared with the same dose from a conventional eye drop. Lyophilisates are a favourable alternative to conventional eye drops since they have no preservatives, higher long term stability, no pH adjustment, and easy handling.

Intracranial ependymoma in the adult patient: successful treatment with surgery and radiotherapy

PURPOSE

Ependymoma is an uncommon intracerebral tumor in adults. Since the site of origin frequently prevents complete surgical removal, adjunctive radiotherapy is used to destroy residual disease. We present our experience in treating 10 adults with intracranial ependymoma.

METHODS

Five men and 5 women were treated in the past 16 years. The median age was 38 (range 24-69). All had contrast enhanced CT or MRI showing the extent of the tumor. One patient had total excision while the remainder had subtotal removal. Radiation therapy was delivered to the tumor bed with a 1-2 cm margin of normal tissue generally at 180-200 centiGray (cGy) per treatment once a day. Total dose ranged from 5400 to 7200 cGy. Two patients received experimental treatment with 100 cGy delivered twice a day for total of 6800 and 7200 cGy respectively. Four patients received initial treatment to a large field with a subsequent boost to the tumor bed. One patient received his entire course of treatment via this large field.

RESULTS

With a median follow-up of 64 months, 7 patients are alive and free of disease while 2 died of intercurrent disease, without evidence of tumor, at 7 and 9 years following treatment. Another patient died 1 1/2 years after treatment of unknown causes.

CONCLUSION

We conclude that postoperative radiotherapy is effective in preventing regrowth of intracranial ependymoma following subtotal resection in adults. Treatment fields should cover the initial tumor bed with a 1-2 cm margin to avoid long term radiation damage.

Multiple myeloma of an extremity: must the entire bone be treated?

PURPOSE/OBJECTIVE

Radiation of the entire shaft of a long bone affected by multiple myeloma (MM) is often advocated to prevent recurrent disease in the bone remote from the symptomatic site. Our standard of care has been to irradiate only the symptomatic area. We investigated the pattern of recurrence in patients treated in this manner.

METHODS AND MATERIALS

163 patient with MM were treated between 1971 and 1994. Twenty-seven patients received treatment to a long bone with 41 sites irradiated (17 humeri, 22 femurs, 1 radius, 1 ulna). The most common long bone treated was the femur. All patients were treated with megavoltage therapy. The symptomatic lesion, plus a margin of 1-2 cm was treated with no attempt to treat the entire shaft. Mean radiation dose was 27.82 Gy (range 6.00-44.80 Gy). The length of the field was measured in centimeters and expressed as both an absolute (AL) and relative (RL) length (i.e., percentage of total length of bone).

RESULTS

The mean total AL and RL for femur fields was 18 cm and 42%, respectively. For the humerus, the AL and RL were 20 cm and 68%, respectively. Only four patients developed progressive disease in the same bone but outside the previously irradiated field. In three of the four patients the RL was between 20 and 30%. The dose of radiation given to these patients was 12.50, 21.00, 30.00, and 35.00 Gy. In all of these four cases, treatment of progressive disease in adjacent sites provided effective palliation of symptoms.

CONCLUSION

Radiation therapy to the symptomatic portion of a long bone affected by MM is effective for palliation. Symptomatic recurrence out of the irradiated field is uncommon and can be effectively treated. Potential benefits of this approach include irradiation of less normal marrow and elimination of use of pairs of fields or extended distance treatment to cover the entire femur.

Final results of a phase II chemoradiation protocol for locally advanced cervical cancer: RTOG 85-15

BACKGROUND

The lack of improved cure rates for advanced cervical cancer after three decades of megavoltage radiotherapy (RT) has prompted continued efforts in improved treatment delivery. Concurrent chemoradiation (CR) is one of the several avenues being explored to improve these results.

METHODS

Sixty women with advanced cervical cancer (30 patients with unfavorable Stage IIB and 30 patients with Stages III and IVA) were treated with CR comprising of a combination of external and intracavitary RT delivering between 7000 to 7500 cGy total to point A and 5890 to 6015 cGy to point B along with one cycle of 5-FU and mitomycin C and a second cycle of 5-FU and cis-platinum.

RESULTS

Grade 3 and 4 RT-related toxicities were 15 and 3%, respectively. Chemotherapy-related Grade 3 and 4 toxicities were 9 and 2%, respectively. The 5-year survival for unfavorable Stage IIB patients was 48%; for Stages III and IVA it was 39%.

CONCLUSIONS

The toxicity of this particular CR regimen was acceptable and suggests that further qualitative and quantitative intensification of chemoradiation may be attempted. Retrospective comparisons with PCS studies and previous RTOG studies 79-20 and 80-05 suggest that this particular chemoradiation regimen may offer a modest survival advantage over RT alone for Stages III and IVA disease. A CR regimen with higher doses of radiotherapy and a greater number of active chemotherapeutic agents may yet result in acceptable toxicity and further improve cure rates in advanced and poor prognostic featured cervical cancer.