Neoadjuvant concurrent chemoradiotherapy with and without hyperthermia in retroperitoneal sarcomas: feasibility, efficacy, toxicity, and long-term outcome.

PURPOSE: Retroperitoneal (RPS) sarcomas are associated with poor local and abdominal tumor control. However, the benefit of preoperative radio- or chemotherapy alone for these entities is currently unclear. Moreover, as intermediate- and high-grade sarcomas have a tendency toward early metastasis, exploration of neoadjuvant strategies is of high importance. This analysis reports the results of our 20-year single-institution experience with preoperative neoadjuvant concurrent chemoradiation. METHODS: From 2000-2019, 27 patients with intermediate- or high-grade RPS (12 dedifferentiated liposarcoma, 10 leiomyosarcoma, 5 others) were treated with radiotherapy (median dose: 50.4 Gy; range 45-75 Gy) and two cycles of chemotherapy (doxorubicin 50 mg/m2 BSA/d3 q28 and ifosfamide 1.5 g/m2 BSA/d1­5 q28) in neoadjuvant intent. Chemotherapy consisted of doxorubicin alone in two cases and ifosfamide alone in one case. Fifteen patients (56%) additionally received deep regional hyperthermia. RESULTS: The median follow-up time was 53 months (±56.7 months). 92% of patients received two cycles of chemotherapy as planned and 92% underwent surgery. At 5 and 10 years, abdominal-recurrence-free survival was 74.6% (±10.1%) and 66.3% (±11.9%), distant metastasis-free survival was 67.2% (±9.7%) and 59.7% (±11.1%), and overall survival was 60.3% (±10.5%) and 60.3% (±10.5%), respectively. CTC grade III and IV toxicities were leukocytopenia (85%), thrombocytopenia (33%), and anemia (11%). There were no treatment-related deaths. CONCLUSION: Neoadjuvant chemoradiotherapy with and without hyperthermia for retroperitoneal sarcomas is feasible and provided high local control of intermediate- and high-grade sarcoma.

Pulsed operation of a high average power Yb:YAG thin-disk multipass amplifier.

An Yb:YAG thin-disk multipass laser amplifier system was developed operating in a 10 Hz burst operation mode with 800 µs burst duration and 100 kHz intra-burst repetition rate. Methods for the suppression of parasitic amplified spontaneous emission are presented. The average output pulse energy is up to 44.5 mJ and 820 fs compressed pulse duration. The average power of 4.45 kW during the burst is the highest reported for this type of amplifier.

Coherent spectral enhancement of carrier-envelope-phase stable continua with dual-gas high harmonic generation.

Attosecond science is enabled by the ability to convert femtosecond near-infrared laser light into coherent harmonics in the extreme ultraviolet spectral range. While attosecond sources have been utilized in experiments that have not demanded high intensities, substantially higher photon flux would provide a natural link to the next significant experimental breakthrough. Numerical simulations of dual-gas high harmonic generation indicate that the output in the cutoff spectral region can be selectively enhanced without disturbing the single-atom gating mechanism. Here, we summarize the results of these simulations and present first experimental findings to support these predictions.

Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification.

We report on a Yb:YAG Innoslab laser amplifier system for generation of subpicsecond high energy pump pulses for optical parametric chirped pulse amplification (OPCPA) at high repetition rates. Pulse energies of up to 20 mJ (at 12.5 kHz) and repetition rates of up to 100 kHz were attained with pulse durations of 830 fs and average power in excess of 200 W. We further investigate the possibility to use subpicosecond pulses to derive a stable continuum in a YAG crystal for OPCPA seeding.

Coherent control of high harmonic generation via dual-gas multijet arrays.

High harmonic generation (HHG) is a central driver of the rapidly growing field of ultrafast science. We present a novel quasiphase-matching (QPM) concept with a dual-gas multijet target leading, for the first time, to remarkable phase control between multiple HHG sources (>2) within the Rayleigh range. The alternating jet structure with driving and matching zones shows perfect coherent buildup for up to six QPM periods. Although not in the focus of the proof-of-principle studies presented here, we achieved competitive conversion efficiencies already in this early stage of development.

High harmonic generation by novel fiber amplifier based sources.

Significant progress in high repetition rate ultrashort pulse sources based on fiber technology is presented. These systems enable operation at a high repetition rate of up to 500 kHz and high average power in the extreme ultraviolet wavelength range via high harmonic generation in a gas jet. High average power few-cycle pulses of a fiber amplifier pumped optical parametric chirped pulse amplifier are used to produce µW level average power for the strongest harmonic at 42.9 nm at a repetition rate of 96 kHz.

High average and peak power few-cycle laser pulses delivered by fiber pumped OPCPA system.

We report on a high power optical parametric amplifier delivering 8 fs pulses with 6 GW peak power. The system is pumped by a fiber amplifier and operated at 96 kHz repetition rate. The average output power is as high as 6.7 W, which is the highest average power few-cycle pulse laser reported so far. When stabilizing the seed oscillator, the system delivered carrier-envelop phase stable laser pulses. Furthermore, high harmonic generation up to the 33(th) order (21.8 nm) is demonstrated in a Krypton gas jet. In addition, the scalability of the presented laser system is discussed.

Fiber-amplifier pumped high average power few-cycle pulse non-collinear OPCPA.

We report on the performance of a 60 kHz repetition rate sub-10 fs, optical parametric chirped pulse amplifier system with 2 W average power and 3 GW peak power. This is to our knowledge the highest average power sub-10 fs kHz-amplifier system reported to date. The amplifier is conceived for applications at free electron laser facilities and is designed such to be scalable in energy and repetition rate.

Fine tuning of conversion/dispersion based optical delays with a 1 pm tunable laser using cascaded acousto-optic mixing.

We demonstrate a technique for fine tuning of optical delays using cascaded acousto-optic modulators to improve the delay resolution by 5 orders of magnitude compared to a 1 pm tunable laser. A 256 ns delay with <0.5 ps resolution is shown for 40 Gbits/s return-to-zero on-off keying with no added penalty.

Higher-order dispersion compensation to enable a 3.6 micros wavelength-maintaining delay of a 100 Gb/s DQPSK signal.

We demonstrate a method for dispersion slope compensation of a conversion/dispersion-based optical delay to enable 100 Gb/s operation based on a spatial light modulator and fiber Bragg gratings. A continuous delay of up to 3.6 micros for 100, 80, and 20 Gb/s differential quadrature phase-shift-keyed (DQSPK) and 50, 40, and 10 Gb/s differential phase-shift-keyed (DPSK) waveforms is shown. A time-delay bit-rate product of approximately 360,000 for 100 Gb/s DQPSK with wavelength-maintaining operation is achieved.

Continuously tunable 1.16 micros optical delay of 100 Gbit/s DQPSK and 50 Gbit/s DPSK signals using wavelength conversion and chromatic dispersion.

We demonstrate a variable optical delay element that uses tunable wavelength conversion and phase conjugation in highly nonlinear fiber and uses chromatic dispersion in dispersion-compensating fiber. A continuous delay of up to 1.16mus, equaling a >110,000 time-delay bit-rate product for 100 Gbit/s non-return-to-zero differential quadrature phase-shift-keying (NRZ-DQSPK) and >55,000 for 50 Gbit/s NRZ differential phase-shift-keying (NRZ-DPSK) modulation formats, is demonstrated. Bit error rates <10(-9) are demonstrated for each waveform at various delay settings.

Variable rate, multi-format receiver design for 10 to 40 Gb/s DPSK and OOK formats.

We demonstrate a continuously-variable bit-rate receiver from 10 to 40 Gbit/s for DPSK demodulation. Unlike previous DPSK demodulators, this receiver is also capable of passing intensity modulated waveforms without distortion. Degradations imposed by receiver imperfections are presented and compared with a traditional DPSK delay-line interferometer.

All-optic scheme for automatic polarization division demultiplexing.

We describe a cost effective scheme to automatically separate two polarization channels in a polarization division multiplexing (PDM) system, without having to modify the existing transmitter or receiver electronics or software. We experimentally validate the concept by achieving an extinction ratio of more than 28-dB between two demultiplexed channels. Finally, we successfully demonstrate the PDM scheme in a 1.12-Tb/s (14x2x40-Gb/s) system over 62-km of transmission fiber.

Continuously-tunable, bit-rate variable OTDM using broadband SBS slow-light delay line.

We conceptually compare the advantages of the proposed slow-light-based tunable OTDM to conventional fiber-based fixed OTDM multiplexer. We experimentally demonstrate continuously-controllable OTDM of two 2.5-Gb/s return-to-zero (RZ) signals using broadband SBS-based slow-light as the tunable optical delay line. We show that the time slot of one signal path can be manipulated relative to the other by as much as 75-ps. This continuous slow light tunability dramatically enhances the OTDM system performance which results in a power penalty reduction of 9-dB for the multiplexed data stream. We also demonstrate variable-bit-rate OTDM by dynamically adjusting the tunable slow-light delay according to the input bit-rates. We show efficient two-by-one optical time multiplexing of three different input data streams at 2.5-Gb/s, 2.67-Gb/s and 5-Gb/s.

A 10-Gbit/s EML link using detuned narrowband optical filtering.

In this paper, the effects of asymmetric narrowband optical filtering are investigated in a 10-Gbit/s optical communication link using integrated electro-absorption modulated lasers (EML). We investigate the effect of EML chirp on link performance as well as the optimal filter bandwidth and wavelength detuning. We show that both the phase response and the spectral narrowing of the filter will enable a longer distance transmission by interacting with the EML transient chirp and compensating for the fiber chromatic dispersion. Experimentally, an 8.75-GHz filter is shown to improve the link distance by 40 km from 65 to 105 km, when transmitting over standard single mode fiber.

Reach extension in 10-Gb/s directly modulated transmission systems using asymmetric and narrowband optical filtering.

Optical filtering has been used to extend the reach of directly modulated laser in 10Gb/s WDM systems via two separate mechanisms: narrowing the broadened spectrum, and converting frequency modulation into useful amplitude modulation. We investigate in detail, the impact of asymmetric and narrowband optical filtering at the transmitter or receiver. Experimental demonstrations for both shorter distance and long-haul like transmission using optical filtering are performed. The transmission reach is nearly doubled from <25-km to >45-km without dispersion compensation. 1400-km error-free transmission (Q > 15.6-dB) is further achieved over dispersion-managed link for a directly modulated DFB laser within an 8x10-Gb/s WDM system.

Analogical reasoning and postoperative outcome. Predictions for patients scheduled for open heart surgery.

We investigated whether postoperative outcome of open heart surgery is related to preoperative cognitive dysfunction. Patients ill enough to require open heart surgery frequently have gravely compromised circulation and, hence, possible brain damage. The Conceptual Level Analogy Test (CLAT), a new, rigorously constructed analogy test, was used to measure cognitive dysfunction. The results indicated that the CLAT, aministered preoperatively to open heart surgery patients, differentiated between patients having different types of postoperative outcome. A significant relationship between type of surgical procedure and poor postoperative outcome was also found; cardiac valvular surgery patients had significantly worse outcome than coronary bypass surgery patients. The incidence of good outcome (survival with no psychiatric complications) was 28% for cardiac valvular surgery patients with extremely poor preoperative CLAT scores, but 74% for valvular surgery patients with higher preoperative CLAT scores.

Analogy tests and psychopathology at follow-up after open heart surgery.

A study of 100 coronary bypass and cardiac valvular surgery patients investigated whether preoperative brain damage, as measured by the Conceptual Level Analogy Test (CLAT), is a major risk factor for postoperative psychiatric symptoms and mortality. Three cognitive psychological tests, including the CLAT, and psychatric interviews were given preoperatively, postoperatively, and at 18-month follow-up. Surgical outcome was specified as: Catastrophic Outcome (death or severe stroke), Psychiatric Complications, or Good Outcome (survival with no psychiatric complications). Inhospital outcome related significantly to analogy test scores, as did both surgical procedure and diagnosis of rheumatic heart disease. However, long-term outcome was unrelated to medical diagnosis and only weakly related to surgical procedure, but highly significantly related to preoperative analogy scores. The CLAT was a more consistent predictor of both short- and long-term outcome than any of the other ten variables considered (medical and surgical variables, inhospital outcome, demographic measures, other psychological tests).

Extraluminal laryngotracheal fixation with absorbable miniplates.

OBJECTIVE: To determine if miniplates made of polydioxanone can be used successfully for extraluminal laryngotracheal fixation. DESIGN: Twelve rabbits underwent anterior and posterior laryngotracheofissure with extraluminal fixation of the divided segments with polydioxanone miniplates. Three control animals did not undergo plating. Animals were killed after 2, 4, and 12 weeks. Larynges were removed and examined to determine the intraluminal area and histologic status of the repair site. RESULTS: The intraluminal area of the animals in the experimental group was 1.6 times that of those in the control group. The trachea was relined with respiratory mucosa by 2 weeks. Little inflammatory reaction was evident. Plate resorption was almost complete at 12 weeks. CONCLUSION: Polydioxanone plating is a feasible and well-tolerated method of extraluminal laryngotracheal fixation. It may be useful in the treatment of grade 2 or 3 subglottic stenosis.

Auricular injury as a presentation of child abuse.

Child abuse causes serious physical and emotional injury. Those abused, however, are usually unable or unwilling to gain access to agencies that might help them. The otolaryngologist, while usually not the patient's primary physician, may be in the position to detect child abuse. We describe a 3-year-old boy who sustained auricular trauma as the result of child abuse. The importance of physician recognition of an abuse case and the institution of appropriate measures are discussed.