Prospective trial of proton reirradiation of locally recurrent esophageal cancer

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Background: Local recurrences of esophageal cancer occur in approximately 25% of patients and cause significant morbidity. Their treatment after esophagectomy and chemoradiation is particularly challenging. A second course of radiotherapy in a previously radiated field carries the risk of radiation-induced tissue injury. Proton therapy (PRT) may offer an advantage in the re-irradiation setting due to the lack of exit dose and potential sparing of normal tissues. Methods: Between 6/2011 and 8/2013, 10 adult patients (pts) with locally recurrent esophageal cancer, initially cT1b-T4N0-1, in or near prior treatment fields began reirradiation. Toxicity was graded according to the Common Toxicity Criteria version 4.0. Acute toxicity was defined as occurring within 90 days from start of PRT. Results: The median follow-up was 7.9 months (1-23) from the start of retreatment, and 15 months (2.4-27.8) from the development of local recurrence. Mean age was 70 (53-91). ECOG PS was 0 (n=4), 1 (4), 2 (2). Eight pts had intraluminal and two had paratracheal nodal recurrences. Eight of the pts had adenocarcinoma and two squamous cell carcinoma. Median CTV size was 138 cc (32-390). Seven received concurrent chemotherapy. The median total dose was 54.0 Gy (50.4-61.2); all pts were treated with PRT exclusively (9 double scatter and 1 uniform scanning), except for two pts who were treated with 15-30% IMRT. The median prior dose was 55.8 Gy (45-70). The median interval between radiation courses was 31.4 mos (12-105). Maximum acute toxicity was grade 2 (30%), 3 (30%), and 4 (40%). Of the grade 4 toxicities, one was an esophagopleural fistula and respiratory failure unlikely related to RT, and 3 were neutropenic toxicities possibly related to RT. Three pts developed metastatic disease at a median of 28 mos after starting RT. Three pts developed in-field locoregional recurrence at a median of 13 mos. Five pts died after a median of 13 mos. Conclusions: Preliminary results using PRT for reirradiation of esophageal cancers shows that local control can be achieved in a large proportion of pts with moderate but acceptable acute toxicity. Further follow-up on these pts is needed to assess the long-term utility of PRT reirradiation. Clinical trial information: NCT01126476.

Radiation oncology: a primer for medical students

Radiation oncology requires a complex understanding of cancer biology, radiation physics, and clinical care. This paper equips the medical student to understand the fundamentals of radiation oncology, first with an introduction to cancer treatment and the use of radiation therapy. Considerations during radiation oncology consultations are discussed extensively with an emphasis on how to formulate an assessment and plan including which treatment modality to use. The treatment planning aspects of radiation oncology are then discussed with a brief introduction to how radiation works, followed by a detailed explanation of the nuances of simulation, including different imaging modalities, immobilization, and accounting for motion. The medical student is then instructed on how to participate in contouring, plan generation and evaluation, and the delivery of radiation on the machine. Lastly, potential adverse effects of radiation are discussed with a particular focus on the on-treatment patient.

An in-silico comparison of proton beam and IMRT for postoperative radiotherapy in completely resected stage IIIA non-small cell lung cancer

INTRODUCTION

Post-operative radiotherapy (PORT) for stage IIIA completely-resected non-small cell lung cancer (CR-NSCLC) has been shown to improve local control; however, it is unclear that this translates into a survival benefit. One explanation is that the detrimental effect of PORT on critical organs at risk (OARs) negates its benefit. This study reports an in-silico comparative analysis of passive scattering proton therapy (PSPT)- and intensity modulated proton therapy (IMPT) with intensity modulated photon beam radiotherapy (IMRT) PORT.

METHODS

The computed tomography treatment planning scans of ten patients with pathologic stage IIIA CR-NSCLC treated with IMRT were used. IMRT, PSPT, and IMPT plans were generated and analyzed for dosimetric endpoints. The proton plans were constructed with two or three beams. All plans were optimized to deliver 50.4 Gy(RBE) in 1.8 Gy(RBE) fractions to the target volume.

RESULTS

IMPT leads to statistically significant reductions in maximum spinal cord, mean lung dose, lung volumes treated to 5, 10, 20, and 30 Gy (V5, V10, V20, V30), mean heart dose, and heart volume treated to 40 Gy (V40), when compared with IMRT or PSPT. PSPT reduced lung V5 but increased lung V20, V30, and heart and esophagus V40.

CONCLUSIONS

IMPT demonstrates a large decrease in dose to all OARs. PSPT, while reducing the low-dose lung bath, increases the volume of lung receiving high dose. Reductions are seen in dosimetric parameters predictive of radiation pneumonitis and cardiac morbidity and mortality. This reduction may correlate with a decrease in dose-limiting toxicity and improve the therapeutic ratio.

Multi-institutional study of reirradiation with proton beam radiotherapy for non-small cell lung cancer

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Background: The management of recurrent non-small cell lung cancer (NSCLC) in the setting of prior radiation (RT) is complex. Proton radiotherapy (PRT) is ideally suited to minimize toxicity by sparing dose to previously-irradiated organs. Herein we report the safety and feasibility of PRT for NSCLC reirradiation. Methods: Patients (pts) with recurrent NSCLC in or near their prior RT field were identified in three proton centers. An interval of 3 months was required between original RT course and PRT start. Pts were classified as low volume (LV, clinical target volume [CTV] ≤250 cc) or high volume (HV, CTV >250 cc). PRT was deemed infeasible if pts were unable to tolerate 15% of fractions or complete all treatments in <10 days of estimated end date and without a break ≥5 days. Results: Between 10/2010-11/2012, 24 pts were reirradiated, with 12 on a prospective trial of PRT for reirradiation. Median age was 69 (51-89). Histologies included squamous cell carcinoma (50%), adenocarcinoma (39%), and other (13%). Stage at initial diagnosis was I (8.3%), II (20.8%), III (50%), IV (12.5%), and unknown (8.3%). All pts were ECOG PS 0-2. Median prior dose was 62.4 Gy (30.6-80); 1 pt had 2 prior RT courses. The majority of pts (63%) were LV (median CTV 75.3, 11.9-236) and 38% were HV (359, 297.8-695.7). Concurrent systemic therapy (platinum-based or erlotinib) was given in 63%. Median PRT dose was 66.6 Gy (36-74). Average mean lung dose was 7.6 and 10.8 Gy and lung volume receiving 5 and 20 Gy was 16 and 24% and 26 and 33% in LV and HV pts, respectively. Follow up was >60 days in 17 pts. Overall, 46% of pts were hospitalized. PRT was infeasible in 3/9 HV and 1/15 LV pts. In HV pts, there were 2 grade 5 toxicities (hemoptysis and neutropenic fever). There was 1 in-field and 4 other thoracic recurrences, and 5 and 4 deaths in LV and HV pts, respectively. Conclusions: Preliminary results show promising early outcomes and acceptable toxicity in LV pts; due to the toxicity seen in HV pts, additional exclusion criteria were added for NSCLC pts in the ongoing trial. NSCLC reirradiation should continue to be studied in prospective trials to identify pts that may derive clinical benefit. Mature follow up is needed prior to standardizing NSCLC reirradiation with PRT.

Dietary Flaxseed in Non-Small Cell Lung Cancer Patients Receiving Chemoradiation

Purpose

The standard of care in Locally-Advanced Non-Small Cell Lung Cancer (LA-NSCLC) is chemotherapy and radiation; however, Radiation-Induced Lung Injury (RILI), which may be prevented by the anti-inflammatory and anti-oxidant properties of Flaxseed (FS), impedes its maximum benefit.

Materials and Methods

Patients with LA-NSCLC requiring definitive RT were randomized to one FS or control muffin daily from start to 2 weeks after RT. Blood and urine were collected to quantify plasma FS metabolites, Enterodione (ED) and Enterolactone (EL), and urinary oxidative stress biomarkers, 8, 12-iso-iPF2a-VI (isoprostane) and 8-oxo-7,8-dihydro-2′deoxyguanosine (8-oxo-dGuo). Tolerability was defined as consuming ≥ 75% of the intended muffins and no ≥ grade 3 gastrointestinal toxicities.

Results

Fourteen patients (control,7; FS,7) were enrolled. The tolerability rates were 42.9 versus 71.4% (p=0.59) for FS and control, respectively. Mean percentages of intended number of muffins consumed were 37% versus 73% (p=0.12). ED and EL increased at onset of FS and decreased with discontinuation, confirming bioavailability. Isoprostane and 8-oxo-dGuo were detectable. There was a trend towards decreased rates of pneumonitis in FS.

Conclusions

This is the first study to report FS bioavailability and quantify oxidative stress markers in NSCLC patients. FS in the administered muffin formulation did not meet tolerability criteria. Given the promising mechanism of FS as a radioprotectant, further investigations should focus on the optimal method for administration of FS.

Integrating immunotherapy into chemoradiation regimens for medically inoperable locally advanced non-small cell lung cancer

For patients with inoperable stage II-III non-small cell lung cancer (NSCLC), the backbone of curative intent therapy is concurrent chemoradiotherapy (CRT). As checkpoint inhibitors have shown clinical benefit in the setting of metastatic NSCLC, additional study is necessary to understand their role in patients receiving CRT. When integrating immunotherapy with radiotherapy (RT) for cure, clinicians will need to consider synergy, timing, doses, and safety among the combination of therapies. This article seeks to review data evaluating interactions, temporal sequencing, fractionation, and overlapping toxicity profiles of thoracic chemoradiation and immunotherapy.

Compression arthrodesis of the ankle by triangular external fixation: biomechanical and clinical evaluation

This article describes a technique of ankle arthrodesis using a triangular external fixation frame and presents the results of biomechanical analysis and clinical experience with the frame. Clinical evaluation of 23 ankle arthrodeses performed using a triangular external fixation frame yielded a 91.3% fusion rate at an average of 11 weeks postfusion. The triangular frame was 79% stiffer than a compression-only external frame in torsion and 39% stiffer in anteroposterior bending. This high rate of fusion is attributed to the elimination of micromotion at the fusion site because of the increased rigidity of the triangular external compression frame.

The incidence of large venous emboli during total knee arthroplasty without pneumatic tourniquet use

Echogenic venous emboli accompany tourniquet deflation during total knee arthroplasty. Two types of echogenic emboli appear in the central circulation: small venous emboli (miliary emboli) and large venous emboli (masses of echogenic material superimposed on miliary emboli). Presumably, medullary cavity trespass releases small and large echogenic emboli. However, patients undergoing lower extremity procedures with a tourniquet have large echogenic emboli regardless of medullary cavity invasion. Avoiding tourniquet inflation may decrease the release of large venous emboli. Thirteen patients undergoing total knee arthroplasty without pneumatic tourniquet received intramedullary guides and 11 patients received tibial extramedullary guides. Recordings of hemodynamic variables, mixed venous oximetry, end-tidal CO2, and echocardiographic images were made after the induction of anesthesia and for 15 min after femoral prosthesis cementing. Mean arterial pressure did not change during the study, and mean pulmonary arterial pressure increased minimally. Large venous emboli appeared in eight patients, small venous emboli appeared in 12 patients, and no emboli appeared in four patients. Compared with previous investigations of large venous emboli during total knee arthroplasty with a pneumatic tourniquet, multiple logistic regression analysis discloses a 5.33-fold greater risk of large venous embolism accompanied the use of a tourniquet during total knee arthroplasty.

IMPLICATIONS

One third of knee replacements performed without a tourniquet demonstrated large emboli. Reducing marrow cavity invasion did not decrease the release of large emboli. Compared with knee replacement without tourniquet, tourniquet use places patients at a 5.33-fold greater risk of having a large emboli.

Emboli observed with use of transesophageal echocardiography immediately after tourniquet release during total knee arthroplasty with cement

The right atrium and the right ventricle of fifty-five patients were imaged with transesophageal echocardiography during fifty-nine total knee arthroplasties performed with cement and the use of general anesthesia. The patients ranged in age from thirty-two to eighty-three years (mean, 65.5 years). Cardiopulmonary parameters were measured with use of hemodynamic monitoring systems, such as pulse oximeters, pulmonary artery catheters, and radial artery catheters. In addition, a femoral vein catheter was inserted on the side of the operation in ten of the fifty-five patients. Showers of echogenic material traversing the right atrium, the right ventricle, and the pulmonary artery after the tourniquet was deflated were observed to various degrees in all patients and lasted three to fifteen minutes. The mean peak intensity occurred within thirty seconds (range, twenty-four to forty-five seconds) after the tourniquet was released. The mean mixed venous oxygen saturation (and standard error of the mean) decreased (from 83+/-0.9 to 72+/-1.5 per cent) and the mean pulmonary arterial pressure increased (from 20+/-1.0 to 27+/-1.0 millimeters of mercury [2.67+/-0.13 to 3.60+/-0.13 kilopascals]), compared with the values before the tourniquet was released, in all patients. The pulmonary vascular resistance index increased after release of the tourniquet (to a maximum of 328+/-29 dyne.s.cm(-5).m2; p = 0.00002) only in the patients who had echogenic material that was at least 0.5 centimeter in diameter. Clinical pulmonary embolism developed postoperatively in three patients; all three had had echogenic particles that were more than 0.5 centimeter in maximum diameter on imaging. Blood aspirated from one of the pulmonary artery catheters and from five of the ten femoral vein catheters demonstrated fresh venous thrombus. Histological evaluation of the aspirates failed to demonstrate fat, marrow, or particles of polymethylmethacrylate. Surgeons should consider acute pulmonary embolism as a diagnosis when evaluating a patient who has hemodynamic collapse during total knee arthroplasty performed with cement.

Pseudoaneurysm following femoral fracture

If the physician is aware of this diagnosis and maintains an appropriate level of suspicion and low threshold to commence duplex evaluation. The potential morbidity of a fracture-induced traumatic pseudoaneurysm can be minimized.

Functional results of percutaneous laser discectomy

The purpose of the study was to evaluate laser disc decompression with the KTP 532 laser, used in conjunction with a percutaneous technique, in contained, small to moderately sized lumbar disc herniation. Sixty-three patients who had a contained herniated nucleus pulposus (HNP) and underwent percutaneous laser disc decompression were prospectively studied. Sixty-one were available for follow-up. Access to the disc space was attained with an 18-gauge probe, followed by dilating cannulas guided with an image intensifier. Discography was not performed. The power was set at 10 W, and laser pulses were delivered for 0.2 seconds, with an interval of 0.5 seconds. A total of 1250 J was delivered to the disc space. The average follow-up was 31.75 months (range, 20 to 45 months). Overall, 44 patients (72%) achieved relief of radicular pain, and 33 patients (54%) achieved relief of low back pain. Thirty-six of 61 patients (59%) returned to work by postoperative week 4. Fourteen patients failed treatment, experiencing persistent symptoms (with scores on the Andrews and Lavyne rating scale of < or = 3). In this study group, optimal results were obtained when symptoms were treated within 1 year of presentation. Results from a historical control group are provided for comparison.

A six-degrees-of-freedom instrumented linkage for measuring the flexibility characteristics of the ankle joint complex

Diagnosis of ligament injuries to the ankle joint complex is a difficult clinical problem which relies primarily on manual physical examination and on radiographic evaluations. In an attempt to develop a reliable, quantitative diagnostic tool for such injuries we developed a six-degrees-of-freedom instrumented linkage (Ankle Flexibility Tester-AFT) capable of measuring the flexibility characteristics of the ankle joint complex in vivo. The unique non-serial structure of this linkage was such that these characteristics were recorded directly in an ]anatomical coordinate system which enhanced clinical interpretation. The goal of the present study was to develop this linkage and to test its accuracy and its test-retest reliability. The positional accuracy of the AFT was measured and was found to be better than 0.5 mm for translation and 1.2 degrees for rotations. The results obtained from a study conducted on two cadaveric specimens indicate negligible effect of loading rate on the flexibility characteristics within the range of possible manually applied loads. Finally, the reliability of the AFT was examined from test-retest studies conducted on a total of thirteen young healthy volunteers. The intraclass correlation coefficient (ICC), calculated from the test-retest data, indicated a reliability higher than 0.85. It was concluded that the high reliability and accuracy of the AFT, its simplicity of operation, the easy alignment procedure, the on-line load-displacement results, and the elimination of complex data processing render this device suitable for use in the clinic as well as in the research laboratory.

Postoperative autotransfusion after total knee arthroplasty

To evaluate the quality of shed blood postoperatively after total knee arthroplasty (TKA), the safety of autotransfusion, and to minimize homologous transfusion, the Autovac system was used for reinfusion of whole blood following cemented TKA. The system was used in 50 consecutive patients who were reinfused an average of 420 cc of whole blood. Twenty-five patients had a calcium binding resin anticoagulant within the collection canister. A second group of 25 patients had 40 cc of acid citrate dextrose anti-coagulate (ACD-A) in the collection canister as an anticoagulant. Fifteen hematologic parameters were measured during five time periods. Each study group was compared to a control group of 25 TKAs with a standard drain. The clinical safety of auto-transfusion with ACD-A was proven. Blood collected in the calcium binding resin had a statistically significant higher hemoglobin (P < .05), plasma-free hemoglobin (P < .05), fibrin split products (P < .05), and a different white blood cell differential.

The incidence of venous emboli during extramedullary guided total knee arthroplasty

During total knee arthroplasty (TKA), instrumentation of the marrow cavity with an intramedullary guide appears responsible for fatal intraoperative pulmonary embolism. Transesophageal echocardiography demonstrates venous emboli (VE) after tourniquet deflation during intramedullary guided TKA. Extramedullary guides avoid manipulating the marrow cavity. We determined the incidence of VE in 20 patients undergoing extramedullary guided TKA. Recordings of hemodynamic variables, mixed venous oximetry, end-tidal CO2 and N2 tensions, and echocardiograph images occurred after induction of anesthesia, after tourniquet inflation, during cementing, and for 15 min after tourniquet deflation. Large VE appeared in 14 patients and small VE in the other 6 patients. Large VE occurred only after deflation of the tourniquet. Beginning 3 min after tourniquet deflation, mean pulmonary arterial pressures increased from the baseline of 21 +/- 1.0 to 30 +/- 1.3 mm Hg and remained increased for the duration of the procedure. The incidence of large VE with extramedullary guided TKA did not differ compared to the previously reported incidence with intramedullary guided TKA. These data suggest that VE might arise from a thrombogenic effect of the tourniquet rather than from manipulation of the marrow cavity.

Results of lumbar disk surgery in a city compensation population

This is a retrospective analysis of 118 patients who underwent 132 operations in a city compensation setting for the treatment of lumbar disk disease from January 1976 to December 1987. Each of these patients had a work-related injury. There was a minimum 2-year follow up with an average follow up of 6.9 years. No patients were lost to follow up. The purpose was to determine what percentage of patients treated in a work-related setting could be expected to return to a sustained, pre-injury employment state following a carefully executed lumbar spine surgical procedure. Satisfactory surgical results were considered achieved only by those patients who returned to full-duty work status. Only 31 of the 118 patients (26%) returned to full duty and were considered satisfactory. Regarding the number of surgical procedures, 31 of 132 operations (23%) were successful. Sixteen reoperations in 13 patients all resulted in failure. Only 16 of the 64 patients (25%) treated with laminectomy and diskectomy alone had a satisfactory result. When a two-level, posterior lateral spinal fusion was added the success rate was increased to 44%, with 12 of 27 patients returning to work. Six patients with spinal stenosis underwent decompression laminectomy and entry level foraminotomies, and all had unsatisfactory results. Five patients with isthmic spondylisthesis underwent a Gill procedure and fusion. Only one of these patients (25%) returned to work. For a 2-year period chymopapain injection was given to 14 patients. Only two returned to work, with a 14% success rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Conversion of resection arthroplasty to total hip replacement

Conversion of Girdlestone arthroplasty is a demanding procedure dependent on adequate debridement at time of resection and appropriate long-term antibiotic therapy. Patients must be followed closely for persistent sepsis through ESR, aspiration, and physical examination. Pre-reconstruction, existing bone stock should be assessed and revision techniques utilized where appropriate. Our experience is that conversion of Girdlestone pseudoarthrosis to THR can yield good functional results and restore independence.

Echogenic emboli upon tourniquet release during total knee arthroplasty: pulmonary hemodynamic changes and embolic composition

Echogenic venous emboli accompany tourniquet deflation during total knee arthroplasty. The associated pulmonary hemodynamic alterations and determined embolic composition were measured in 34 patients, undergoing 35 procedures. Ten patients received a femoral venous catheter on the operative side. Hemodynamic variables, heart rate and mixed venous oximetry, end-tidal CO2 and nitrogen tensions, and transesophageal echocardiograms were recorded after induction of anesthesia (baseline), after tourniquet inflation, after cementing, and for 15 min after tourniquet deflation. Echocardiograms revealed either showers of miliary echogenic material (Group S, 9 patients), or large echogenic masses superimposed on the showers (Group MS, 26 patients). In Group MS only, pulmonary vascular resistance index increased above baseline (205 +/- 16 [SEM] dyne.s.cm-2) beginning 5 min after tourniquet deflation (maximum 328 +/- 29, P < 0.05). Mean pulmonary arterial pressure increased above baseline (20 +/- 1.0 mm Hg) for both Groups S and MS beginning 3 min after tourniquet deflation (27 +/- 1.0, P < 0.05). Cardiac index did not change. Five of 10 patients demonstrated fresh thrombus from the catheter in the operative limb. Echogenic emboli occurred in all patients upon tourniquet deflation during knee arthroplasty. Pulmonary vascular resistance index increased only in patients with large echogenic material. Our data suggest that these emboli represent fresh thrombus formation during tourniquet inflation. Heparin administration prior to tourniquet inflation may diminish embolic showers.

Acetabular osteolysis in total hip arthroplasty: prevention and treatment

Osteolysis can occur around loose, as well as well fixed, cemented or cementless acetabular components in total hip arthroplasty. Histologic studies of tissues biopsied from osteolytic regions suggest an adverse foreign body response to polyethylene and other particulate debris from prosthetic materials. Phagocytosis of these particles by macrophages and giant cells stimulate the production of proteolytic enzymes and inflammatory mediators, all leading to tissue destruction. The importance of polyethylene wear debris is now fully appreciated, and it is clear that this is the major contributor to particulate debris. The authors strongly recommend the avoidance of 32 mm femoral heads, thin acetabular component liners, titanium heads, and acetabular screws when absolutely necessary. We strongly advise 26 mm to 28 mm femoral heads, polyethylene thickness of at least 8 mm, precise liner shell contact, rigid fixation of the acetabular metal shell, intimate bone-acetabular shell contact, and circumferential porous coating of femoral components to decrease the amount of and migration potential of polyethylene debris (Table). Based on our current knowledge, these measures will minimize the problem of acetabular osteolysis.