A Novel Approach to Support Quality Assurance (QA) of Intensity Modulated Neutron Therapy (IMNT)

PURPOSE/OBJECTIVE(S)

Neutron therapy is a form of high linear energy transfer (LET) radiation treatment shown to be beneficial for the treatment of locally advanced head and neck cancers (HNC) resistant to low LET x-ray and proton therapy treatments. The Clinical Neutron Therapy System (CNTS) at our institution has been in clinical operation for over 35 years, and over 3,400 patients have been treated using 3D conformal neutron radiation therapy. In October of 2022, the clinical commissioning of IMNT was completed and the first-ever patient was treated. A novel patient specific quality assurance (PSQA) program has been developed to support IMNT. We present an analysis of our early experiences and PSQA findings for the first 16+ patients treated with IMNT.

MATERIALS/METHODS

Our pre-treatment IMNT PSQA program includes (1) ionization chamber measurements, (2) a log-file analysis of treatment delivery, and (3) a γ-analysis of the expected and measured doses (fluences) from a novel positron emission portal imaging system based on 12C(n,2n)11C reactions. Patient setup is confirmed on a daily basis with kV portal imaging. We use a modulation factor (MF), defined as the total number of monitor units (MU)/prescribed dose (cGy) per fraction, to identify and help anticipate IMNT plans that may fail our PSQA program.

RESULTS

We have found that IMNT treatments for large, irregularly shaped treatment volumes (e.g., chest wall or head and neck cancers that require treatment of nodes in the lower neck) are more likely to fail PSQA when the MF exceeds 3 MU/cGy. For smaller, more spherical treatment volumes (e.g., base of tongue cancers), plans with a MF up to 3.5 MU/cGy pass our PSQA criteria. Re-optimized plans subsequently passed PSQA with insignificant or no change in tumor coverage and organ-at-risk (OAR) dose. Re-optimized plans also reduced the total number of MU and number of segments, which has the added benefit of decreasing the overall treatment time and patient time on the table. About 10% of early IMNT patients have required plan re-optimization.

CONCLUSION

Our pre-treatment clinical PSQA program and workflow provides useful information to guide IMNT treatment planning and delivery, and helps ensure the safe and accurate delivery of IMNT. Our early experiences suggest IMNT plans with smaller MF values are more likely to pass PSQA than plans with larger values of the MF.

Efficacy of Single-Fraction Postoperative Radiotherapy in Resected, Early-Stage Merkel Cell Carcinoma with High-Risk Features

PURPOSE/OBJECTIVE(S)

Merkel cell carcinoma (MCC) is an aggressive skin cancer with a high recurrence risk. Postoperative radiotherapy (PORT) improves the local recurrence rate (LRR) in early-stage MCC with risk factors per NCCN guidelines: primary tumor size > 1cm, head/neck (HN) location, immunosuppression, lymphovascular invasion (LVI), and positive/narrow surgical margins. Conventionally fractionated PORT (C-PORT, ∼50 Gy in 25 fractions) is often recommended for localized MCC with these risk factors; however, some institutions elect observation. Prior studies suggest LRR of ∼20% for stage I/II MCC with high-risk features managed with surgery alone. C-PORT significantly decreases LRR but may cause significant morbidity and financial toxicity. We have previously reported that single fraction (SF)-PORT with 8 Gy achieves high rates of in-field control both in the metastatic and adjuvant settings with minimal morbidity. Here, we present updated long-term outcomes of SF-PORT, offered as an alternative to C-PORT with the hypothesis that it improves LRR relative to observation while minimizing toxicity, for resected stage I/II MCC.

MATERIALS/METHODS

A retrospective, single-institution analysis was completed for stage I/II MCC patients receiving SF-PORT following surgical management. The primary objective was estimating the LRR, defined as recurrence within 2 cm of the primary tumor. Patients with resected, stage I/II MCC with at least one high-risk feature were offered C-PORT as standard of care or SF-PORT as an alternative.

RESULTS

Forty-six patients (median age: 74.5; range 50-96 years) received SF-PORT to the primary tumor site at a median 44 days after wide local excision (85%), shave/excisional biopsy (13%), or Mohs (2%). Fifty-four percent of patients had 1 high-risk feature, 35% had 2, and 11% had 3 or more. HN (74%) was the most common primary site, 26% of tumors were > 1cm, 26% were LVI+, and 15% of patients were immunosuppressed (pathological margin status was often not available). There were no local recurrences (LRR = 0%) at a median follow-up time of 2.3 years. In-field locoregional control was 96% (44/46 patients) with 2 in-field, regional recurrences observed in draining nodal basins of HN primary lesions. There were 2 out-of-field regional nodal recurrences (1 patient with IMS; neither received elective nodal SFRT). Of 9 patients who received elective nodal SF-PORT, 8 did not have a successful sentinel lymph node biopsy. No MCC-specific deaths were observed. The most common side effect was in-field, grade 1 erythema (13%); no side effects > grade 1 (CTCAE v5) were noted.

CONCLUSION

SF-PORT is associated with a very low LRR which has proven durable with long-term follow-up. The LRR for SF-PORT appears lower than historical controls treated with surgery alone for patients with resected, stage I/II MCC with high-risk features.

Proton Radiation Therapy for Stage IIA/IIB Testicular Seminoma

PURPOSE/OBJECTIVE(S)

Testicular seminoma affects young men and is associated with very favorable prognosis. The evolution in treatment paradigm has focused on minimizing acute and especially late toxicities. Following orchiectomy, while surveillance is favored in Stage I patients, radiotherapy (RT) is a standard treatment option for de novo or relapsed stage IIA or select non-bulky stage IIB disease. Despite low doses, standard RT fields to paraaortic and pelvic lymphatics using x-rays exposes a large volume of uninvolved normal tissue/viscera to excess dose. This young patient population is especially vulnerable to risks of late RT toxicities including secondary malignancy. Proton beam therapy (PBT) has dosimetric advantage over x-ray-based RT due to lack of exit dose, and comparative dosimetric/modeling studies show significant sparing of uninvolved abdominal/pelvic organs. However, there is scant reported clinical data at this time for PBT. We review our early institutional outcomes with PBT for testicular seminoma.

MATERIALS/METHODS

Single institution retrospective review from a tertiary care center of patients treated with PBT from 2013-2022 for testicular seminoma. Recurrence free (RFS) and overall survival (OS) were calculated from the completion of PBT. Toxicities were graded (Gr) using CTCAE v5.0.

RESULTS

Four patients underwent PBT, median age 39 (range 36-47). All were Stage I at diagnosis (pT1b n = 3; pT2 n = 1) and were treated for recurrent stage II disease (IIA n = 3; IIB n = 1) at a median of 34 months from orchiectomy (range 3 - 74 months). Nodal extent included 2 with multiple paraaortic nodes, 1 with solitary paraaortic node and 1 with solitary pelvic node. PBT was delivered with pencil-beam scanning, treating paraaortic + ipsilateral pelvic fields (20 Gy in 10 fractions), then sequential boost to involved nodes (10 -16 Gy in 5-8 fractions). Typically, PA or posterior oblique fields were used to minimize dose to out-of-field abdominal/pelvic viscera. Treatment was well tolerated with minimal acute toxicities: fatigue Gr 1 (n = 3), nausea Gr 1 (n = 3). No Gr 2 or higher acute toxicities or significant late toxicities were observed. At median follow up of 30 months (range 3 - 54), no recurrences were observed, and RFS and OS were 100%. Two patients are without evidence of disease > 4 years post-treatment.

CONCLUSION

In this case series, PBT for retroperitoneal and pelvic metastases in Stage IIA/IIB testicular seminoma was associated with oncologic efficacy with minimal toxicity. PBT reduces unnecessary dose to abdominal/pelvic organs compared to x-ray techniques, which is advantageous in young patients who have anticipated long-term survival. This is one of the few series reporting clinical outcomes of PBT in the management of seminoma. Randomized comparisons with x-ray approaches are impractical given the relatively low volume of patients receiving RT in modern seminoma management, so it is essential to report and track longitudinal outcomes across institutions to validate this approach.

Clinicopathologic Features of Prostate Cancer with Mesorectal Lymph Node Involvement on PSMA or Fluciclovine PET/CT

PURPOSE/OBJECTIVE(S)

Advanced PET imaging has shown more prevalent mesorectal lymph node (LN) involvement in prostate cancer than previously appreciated. The clinical features predicting risk for mesorectal involvement are not well established and the prognostic impact is unclear. This may have implications on management including radiotherapy field design. This study aims to identify clinical and pathologic characteristics associated with mesorectal involvement identified on PSMA or fluciclovine PET/CT.

MATERIALS/METHODS

We conducted a single institution retrospective review of prostate cancer patients with F-18 fluciclovine, F-18 piflufolastat, or Ga-68 gozetotide PET between January 2020 and 2023 demonstrating tracer-avid mesorectal LN in the setting of newly diagnosed disease (ND) or biochemical failure after curative-intent therapy (BF). Clinical characteristics, pathologic findings, and early clinical outcomes were reviewed.

RESULTS

We identified 16 ND and 34 BF patients with uptake in at least one mesorectal LN on PET. For ND patients, clinical features at initial diagnosis were median PSA of 35.2 (range 9.6-659), median grade group 5, and 87% with clinical or radiographic T3/T4 disease. Radiographic PET staging among ND patients (excluding mesorectal LNs) were 19% N0M0, 25% N1M0, 56% as N1M1. For BF patients, clinical features at initial diagnosis were median PSA 9.2 (range 4.1-90) and median grade group 4. Primary treatment was prostatectomy in most (91%), with a high rate of high-risk features: 68% pT3-4, 28% pN1, and 32% had persistent detectable postop PSA. Radiographic PET staging among BF patients (excluding mesorectal LNs) were 29% N0M0, 38% N1M0, 12% N0M1, and 21% as N1M1. High-risk histologic features (cribriform, intraductal, ductal, or neuroendocrine) were identified in 88% of ND and 48% BF patients. Of these patients, 86% had cribriform pattern. Median PSA prior to PET for ND and BF patients was 37.0 (range 8.5-659) and 1.9 (0.2-11.1). Median interval from initial therapy to PET for BF patients was 4.4yr (range 0.2-19.7). Median follow-up post-PET was 8.7mo (range 3.4-29) for ND and 8.8mo (range 0-76) for BF patients. Of patients with M0 PET staging, none of the 7 ND patients developed DMs, and 1 of 23 BF patients developed DM after 4 yrs.

CONCLUSION

In this analysis of prostate cancer patients with mesorectal involvement, we found a high incidence of high grade, T3-4 disease, and cribriform pattern, especially in ND patients. For BF patients, there was a high incidence of pT3-4 and pN1 disease at time of initial treatment. Overall, most patients had concurrent regional nodal disease on PET. Longer follow up of clinical outcomes and comparison to high-risk patients without mesorectal LN involvement is needed to understand the prognostic significance and predictors of mesorectal LN spread. Additional studies are needed to identify patients at highest risk in whom elective coverage of mesorectal lymphatics with elective pelvic nodal RT may be warranted.

Gastrointestinal Toxicity Following Proton and Photon Radiation for Prostate Cancer in Patients with Inflammatory Bowel Disease

PURPOSE/OBJECTIVE(S)

Inflammatory bowel disease (IBD) has been considered a relative contraindication for radiation for prostate cancer (PC) due to concern for gastrointestinal (GI) toxicity. Modern radiation planning techniques such as intensity modulated radiation therapy (IMRT) have resulted in a significant decrease in GI toxicity in the general PC population. Several published case series have suggested overall excellent outcomes using IMRT in PC patients with IBD. Proton therapy (PT) with improved dosimetric sparing of bowel and rectum may offer additional benefit, but to our knowledge, there is no published data assessing outcomes after PT in PC patients with IBD. We report our institutional experience treating PC patients with IBD with both PT and IMRT.

MATERIALS/METHODS

We identified patients with an IBD diagnosis treated for PC at our institution from 2012-2022 with either IMRT or PT. Baseline clinical characteristics were captured, along with radiation parameters, including dose, fractionation, inclusion of pelvic nodes, and use of a rectal spacer. IBD specifics captured included type of IBD, use of IBD medication, and pre radiation colonoscopy findings when available. Early and late GI toxicities were captured via retrospective chart review and graded per the Common Terminology Criteria for Adverse Events (CTCAE) version 5.

RESULTS

Eighteen patients with IBD were treated with RT for PC at our institution, including 10 with ulcerative colitis, 7 with Crohn's disease, and 1 with IBD NOS. Nine of these patients were treated with PT and 9 with IMRT. Most were treated with conventional fractionation (n = 14) and the rest with moderate hypofractionation. Fourteen received primary RT to an intact prostate, and the rest received salvage RT. In four patients, the pelvic nodes were also treated. Rectal spacers were used for 8 patients. Nine of the patients were on IBD medications, and of the 15 patients with records of pre-RT colonoscopy, only 1 demonstrated inflammatory findings, which were noted in the ileum. Median follow-up was 3.5 years (1-6) Acute grade (Gr)1 GI toxicity was seen in 6(33%) patients with diarrhea and proctitis. No patients developed acute Gr 2 GI toxicity, and 1 patient developed acute Gr 3 diarrhea and proctitis. This patient had asymptomatic Crohn's disease prior to IMRT, not on medication, and was treated to the prostate and pelvic nodes. Late Gr 1 GI toxicity was seen in 4 (22%) patients. Median time to late GI toxicity was 9.5 months. No patients developed late Gr 2 or higher GI toxicity.

CONCLUSION

Modern radiation techniques including IMRT and PT are well tolerated in PC patients with well-controlled IBD. Larger studies with longer follow up would be helpful to further characterize these patients' outcomes. In the meantime, IMRT and PT should be considered as treatment options in patients with well-controlled IBD.

Intensity-Modulated Neutron Therapy (IMNT) for Head and Neck Cancer: Early Toxicity Outcomes

PURPOSE/OBJECTIVE(S)

Locally advanced head & neck cancers (HNC) are challenging to treat due to abutment of critical, dose-limiting structures. Fast neutron radiotherapy (NT) is a high linear energy transfer (LET) modality that provides better local control than photons for radioresistant cancers such as salivary gland tumors, but there have been concerns of toxicity with 3D conformal neutron therapy in the past. Recent technological advances have enabled the planning and delivery of IMNT, which improves target conformality and may reduce toxicity compared to 3D conformal NT. We report the first clinical evaluation of early toxicity outcomes of IMNT for HNC.

MATERIALS/METHODS

Study is a single-institution retrospective review of all HNC patients treated with curative-intent IMNT from 10/2022 to 2/2023, using a hospital-based cyclotron (50.5 MeV 1H+ beam incident on a Be target) equipped with an isocentric gantry and multileaf collimator (MLC). A commercial treatment planning system with custom neutron-specific scattering kernels was used for IMNT planning using 4-6 fields. Patient-specific quality assurance included ionization chamber measurements and a novel 12C(n,2n)11C positron emission portal imaging system. kV portal imaging was used to confirm patient setup prior to each treatment session. All patients were prescribed 18.4 Gy at 1.15 Gy/fraction, delivered 4 days/week, which is equivalent to an x-ray EQD2 of approximately 70 Gy (RBE ∼ 3.8). Clinical observations suggest the RBE for radioresistant HNC may be as large as 8. Patients underwent weekly toxicity assessment, and acute toxicities were graded (G) by CTCAE v5.0.

RESULTS

Ten patients received IMNT, median age 61 (range 34-78). Primary tumor sites were base of tongue (n = 3), sinonasal (n = 3), parotid (n = 2), submandibular (n = 1), larynx (n = 1). Tumor histologies included adenoid cystic carcinoma (n = 7), other salivary gland carcinomas (n = 2) and mucosal melanoma (n = 1). Most had T4 disease (n = 8) and one had N3b disease. Six had surgical resection with high-risk features, and 6 had gross measurable disease prior to IMNT. None had concurrent systemic therapy. Uninvolved salivary glands were spared in most patients. All patients completed treatment. Median follow up was 22 days (0-48). Acute toxicities (n, G 1, 2, 3) included skin (8, 3, 0), dysgeusia (1, 6, 0), xerostomia (3, 5, 0), mucositis (2, 0, 5), nausea (3, 0, 1). One patient had >10% weight loss and brief admission for supportive care and PEG placement; one patient had prophylactic PEG; both regained oral independence during follow-up. There was no Grade 4+ toxicity.

CONCLUSION

IMNT improves the therapeutic ratio compared to 3D conformal NT and expands indications for NT in patients with radiorefractory tumors. Acute toxicity compares favorably with photons. Longer clinical and toxicity follow-up is anticipated. A prospective trial is planned to evaluate quality of life measures.

Gastrostomy, tracheostomy, opioid, and health care utilization among patients with recurrent/metastatic head and neck cancer receiving immunotherapy

296

Background: Immune checkpoint inhibitors (ICI) are approved for recurrent and/or metastatic squamous head and neck cancers (R/M HNSCC). Landmark trials have shown stable or improved patient (pt) reported quality of life outcomes. It is unclear how these translate into gastrostomy (G) and tracheostomy (T) dependence, opioid use, or ER/unplanned hospitalizations (UH) in an unselected population. We sought to explore these in our large single institution cohort. Methods: We reviewed R/M HNSCC pts receiving ICI at a tertiary referral NCI designated cancer center. Outcomes were assessed between the first dose of ICI and 100 days after the last dose of ICI. Overall survival (OS) was estimated via Kaplan-Meier estimation. Differences between groups were assessed via log-rank testing procedure and adjusted for age, tumor characteristics, and smoking status. Results: Between 1/2012 and 12/2019, we treated 152 pts with ICI, mostly male (n = 142, 82%), partnered/married (n = 103, 68%), with median age 64 years (range 23 – 90). The most common primary sites were oropharynx (n = 55, 36%) and oral cavity (n = 33, 22%). 50 (35%) had ≥2 lines of prior systemic therapy and 29 (19%) had an ECOG ≥2. The most common pt races were white (n = 114, 75%), Asian (n = 14, 9%), and Hispanic, any race (n = 6, 4%). 83 (55%) and 23 (15%) had history of smoking and heavy alcohol use respectively. Median duration of ICI therapy was 95 days (range 1-1720). Prior to ICI, 49 (32%) had G, 17 (11%) had T, and 15 (10%) had both. While on ICI, 6 (4%) had G placed, and 1 (1%) had a G removed; 1 (1%) had T placed, and 2 (1%) had T removed. 69 (45%) had ER visits and 57 (38%) had UH; 11 (7%) were directly related to ICI adverse effects. Prior to ICI, 104 (68%) were on opiates; requirements increased in 58 (41%) pts and decreased in 17 (12%) pts. Pre-existing G prior to ICI had worse OS on log-rank testing, but significance was lost when adjusted for variables. Pre-existing T prior to ICI (p = 0.001, HR 3.08, 95% Cl [1.56,6.08]), and pts with increasing opiate requirements on ICI (p value = 0.0007, HR 2.13, 95% Cl [1.38,3.28]) had worse OS. Conclusions: In our cohort, ICI did not change G or T usage. Pre-existing T and increasing opiate use were also associated with worse survival. Our data supports augmentation of palliative care and advanced care planning in the R/M HNSCC population.

Performance status (PS) as a predictor of poor response to immune checkpoint inhibitors (ICI) in recurrent/metastatic head and neck cancer (RMHNSCC) patients

BACKGROUND

Anti-PD1 checkpoint inhibitors (ICI) represent an established standard-of-care for patients with recurrent/metastatic head and neck squamous cell carcinoma (RMHNSCC). Landmark studies excluded patients with ECOG performance status (PS) ≥2; the benefit of ICI in this population is therefore unknown.

METHODS

We retrospectively reviewed RMHNSCC patients who received 1+ dose of ICI at our institution between 2013 and 2019. Demographic and clinical data were obtained; the latter included objective response (ORR), toxicity, and any unplanned hospitalization (UH). Associations were explored using uni- and multivariate analysis. Overall survival (OS) was estimated using a Cox proportional hazards model; ORR, toxicity, and UH were evaluated with logistic regression.

RESULTS

Of the 152 patients, 29 (19%) had an ECOG PS ≥2. Sixty-six (44%) experienced toxicity; 54 (36%) had a UH. A multivariate model for OS containing PS, smoking status, and HPV status demonstrated a strong association between ECOG ≥2 and shorter OS (p < 0.001; HR = 3.30, CI = 2.01-5.41). An association between OS and former (vs. never) smoking was also seen (p < 0.001; HR = 2.17, CI = 1.41-3.35); current smoking did not reach statistical significance. On univariate analysis, poor PS was associated with inferior ORR (p = 0.03; OR = 0.25, CI = 0.06-0.77) and increased UH (p = 0.04; OR = 2.43, CI = 1.05-5.71). There was no significant association between toxicity and any patient characteristic.

CONCLUSIONS

We observed inferior OS, ORR, and rates of UH among ICI-treated RMHNSCC patients with ECOG 2/3. Our findings help frame discussion of therapeutic options in this poor-risk population.

Prospective evaluation of a comprehensive geriatric assessment (CGA) in multidisciplinary bladder cancer care: Feasibility and impact on decisional conflict

479

Background: Commonly utilized risk stratification tools demonstrate inconsistent associations with salient clinical outcomes in bladder cancer leading to a disproportionate reliance on providers’ subjective impression of a patient’s fitness for therapy. Current guidelines advocate for use of a CGA to quantify vulnerabilities in older ( > 65 years) patients before treatment selection. Our objective was to prospectively evaluate CGA in our Bladder Cancer Multidisciplinary Clinic (BCMC). We hypothesized that CGA implementation would be feasible and that discussion of the results during shared decision-making would be associated with reduced patient-reported decisional conflict. Methods: Patients seen in BCMC were prospectively enrolled from 6/1/20 to 7/20/21. In the first 3 months, participants underwent non-standardized risk stratification (“Routine cohort”, N = 27). Between 9/1/20 and 7/20/21, participants completed a CGA incorporating validated assessments of frailty, functional status, multimorbidity, nutrition, cognition, and mental health (“CGA cohort”, N = 67). Results were shared with patients during BCMC visits. All patients and providers (three physicians per clinic from: Uro-Oncology, Medical Oncology, and Radiation Oncology) completed a follow-up survey including the Decisional Conflict Scale (DCS). Time required to complete the CGA, completion rates, and patient-reported burden were assessed. Concordance of patient- and provider-reported decisional conflict was compared between Routine and CGA cohorts. Results: Of 138 eligible patients, 94 patients were successfully enrolled (68%) with median age of 72 years, ECOG PS ≥3 in 13%, and Charlson Comorbidity Index ≥3 in 18%, of whom 18% were women. Most patients had pT2 bladder cancer (87%; cN+ and M1 in 23.4% and 9.6%, respectively). CGA component completion rates were 79-100%. Survey response rates were high (patients: 77%, providers: 86%), and most (86%) patients felt that the CGA was, at most, minimally burdensome. Vulnerabilities detected across CGA domains triggered relevant referrals. Patient-reported median (IQR) DCS scores were numerically higher (e.g. greater decisional conflict) for the CGA cohort: (27 [14-33] vs 16 [2-30] for Routine patients, p = 0.28). Provider- and provider reported DCS score was correlated in the CGA (p = 0.04), but not the Routine cohort (p = 0.07). Conclusions: We prospectively evaluated use of CGAs in bladder cancer care and found that CGAs were successfully implemented with high rates of completion and low rates of perceived burden. Notably, in this pilot cohort of 94 patients, DCS scores did not differ significantly between patients and providers with CGA use. Future work will evaluate associations between individual instruments, treatment decisions, clinical outcomes and patient-reported quality of life measures.

High End-of-Life Health Care Utilization in a Contemporary Cohort of Head and Neck Cancer Patients Treated with Immune Checkpoint Inhibitors

Background/Objective: End-of-life health care utilization (EOLHCU) is largely uncharacterized among patients with recurrent/metastatic head and neck squamous cell carcinomas (RMHNSCC), particularly now that immune checkpoint inhibitors (ICI) have been introduced to the treatment landscape. We examined this in a single-institution, retrospective study. Design/Settings: We utilized a database of deceased, ICI-treated RMHNSCC patients to obtain demographic and EOLHCU data, the latter of which included advanced care plan documentation (ACPD) and systemic therapy or emergency room (ER)/hospital/intensive care unit (ICU) admission within 30 days of death (DOD). This was compared with a cohort of deceased thoracic malignancy (TM) patients in an exploratory analysis. Multivariate analysis was performed to examine for association between patient factors (such as age, Eastern Cooperative Oncology Group (ECOG) performance status, or smoking status) and overall survival (OS); associations between the said patient factors and EOLHCU were also evaluated. This study was conducted at an academic, tertiary center in the United States. Results: The RMHNSCC patients (n = 74) were more likely to have ACPD (p < 0.01), an emergency department visit (p < 0.01), and/or hospital admission (p < 0.01) within 30 DOD relative to the TM group. There was no difference in ICU admissions, ICU deaths, or systemic therapy at end of life (EOL). The OS declined in association with ECOG performance status (PS) and smoking. No association was observed between patient factors and any EOLHCU metric. Conclusions: At our center, patients with ICI-treated RMHNSCC have higher rates of both ACPD and EOLHCU, suggesting high symptom burden and representing opportunities for further study into supportive care augmentation.

Timing of postoperative radiation therapy and survival in resected salivary gland cancers: Long-term results from a single institution

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Background: Timely administration of postoperative radiation therapy (PORT) impacts oncologic outcomes in resected squamous cell carcinomas of the head and neck. Salivary gland cancers (SGCs) are uncommon, and timing of PORT has not been extensively explored. We aimed to determine if the interval between surgery and PORT impacts outcomes in SGCs. Methods: We retrospectively identified patients with SGCs who underwent curative intent surgical resection followed by adjuvant PORT at our tertiary referral center. Demographic, tumor, and treatment data were collected. Patients with non-oncologic resections and/or delay of > 6 months to radiation start were excluded. Locoregional control (LRC), relapse free survival (RFS), and overall survival (OS) were estimated using the Kaplan Meier method. A multivariate analysis explored the association between demographics, tumor characteristics, and PORT timing with oncologic outcomes using a stepwise Cox proportional hazards model. Results: Between 1/1/1997 and 12/31/2017 180 eligible patients were identified. Patient characteristics are described in Table. The median time to PORT start was 61 (range 8-121) days, 169 (93.9%) of patients received neutron beam PORT. With a median follow up of 8.2 years in surviving patients, the 5-year OS and LRC estimates were 73% and 67%, respectively. In a multivariate analysis, only nodal involvement, histologic grade, and age at diagnosis were associated with OS, while nodal involvement, tumor size, and age at time of diagnosis were associated with LCR and RFS. Time to PORT start or completion was not statistically associated with survival outcomes on multivariate analysis. Conclusions: SGC patients who underwent surgery in our tertiary institution received PORT within a median of 61 days after surgery. With long term follow up, PORT timing in this retrospective series was not associated with worse oncologic outcomes, and support timely administration of PORT with 3 months of surgical resection. Further work is necessary to assess generalizability of these results.[Table: see text]

Impact of ECOG performance status on recurrent/metastatic head and neck squamous cell carcinomas treated with anti-PD1 inhibitors

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Background: Anti-PD1 checkpoint inhibitors (ICI) represent an established standard of care for patients with recurrent/metastatic head & neck squamous cell carcinoma (RMHNSCC). Landmark studies excluded patients with ECOG performance status (PS) ≥ 2; the benefit of ICI in this population is therefore unknown. Methods: We retrospectively reviewed RMHNSCC patients who received at least 1 dose of ICI at our institution. Demographic data and clinical outcomes were obtained; the latter included objective response to ICI (ORR), physician-documented CTCAE grade 2+ toxicity (irAE), and any unplanned hospitalization within 100-days of last ICI dose (UH). Associations between demographic data and clinical outcomes were explored using both uni- and multivariate analysis. Overall survival (OS) was estimated using a Cox proportional hazards model; ORR, irAE, and UH were evaluated with logistic regression. This project was approved by our institutional IRB. Results: We identified 152 RMHNSCC patients who were treated with ICI between 1/2013 and 1/2019. ECOG PS was 0 in 42 (27%), 1 in 75 (50%), 2 in 27 (18%), 3 in 2 (1%), and unknown in 6 (4%) patients. The median age was 61 (range: 25 - 90). 124 (82%) were male, 124 (82%) were white, and 69 (45%) were never-smokers. The most common primary sites were the oropharynx (n = 59, 40%), oral cavity (n = 39, 26%), nasopharynx (n = 11, 7%), and larynx (n = 10, 6%). 54 (36%) were p16+ oropharynx cancers. CPS score was available in 10 (6.6%). Single agent ICI was received by 118 (77%) patients. 66 (44%) had a documented irAE and 54 (36%) had an UH. A multivariate model for OS containing PS, smoking status and HPV status showed a strong association between inferior OS and ECOG 2/3 compared to 0/1 (p < 0.001; HR = 3.30, CI = 2.01-5.41), as well as former (vs. never) smoking status (p < 0.001; HR = 2.17, CI = 1.41-3.35). Current smoking (p = 0.25) did not reach statistical significance. On univariate analysis, poor PS was associated with inferior ORR (p = 0.03; OR = 0.25, CI = 0.06-0.77) and increased UH (p = 0.04; OR = 2.43, CI = 1.05—5.71). There was no significant association between irAE and any patient characteristic. Conclusions: We observed inferior overall survival among ICI-treated RMHNSCC patients with ECOG 2/3 in our single-institution, retrospective series. Our findings help frame discussion of therapeutic options in this poor-risk population. Further study must be done to determine which interventions are of greatest benefit for RMHNSCC patients with declining performance status.

TraceIT: A prospective pilot study of a temporary intravesical fiducial marker for bladder cancer radiation therapy

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Background: Precision image-guided radiotherapy (RT) for patients (pts) with muscle-invasive bladder cancer (MIBC) is limited by daily anatomic variation and difficulty visualizing the tumor bed. We hypothesized that TraceIT, a radiopaque resorbable hydrogel, can be injected around the tumor bed to improve image guidance. We present the results of our pilot trial (NCT03125226) evaluating safety/feasibility of TraceIT in pts undergoing definitive RT. Methods: Eligibility included MIBC with plan to receive definitive RT +/- chemo. Fifteen patients were available for analysis (11 enrolled on trial from 2017-2018, plus an additional 4 received TraceIT off study). TraceIT was injected around the circumference of the tumor bed during pre-radiation maximal re-transurethral resection of bladder tumor (TURBT) for all pts, and again during the mid-radiation TURBT to improve visibility in n = 8 pts. The primary endpoint was assessment of interfraction motion on daily cone-beam CT (CBCTs) based on alignment to fiducial vs standard-of-care pelvic bone anatomy. Van Herk (VH) margin equation was used to determine the planning target volume margin optimized for the clinical target volume receiving at least 95%-prescription dose in 90% of pts. Recurrence rates and survival were estimated by Kaplan Meier. Toxicity was measured by CTCAE v4.03. Results: Patients underwent RT to a median total dose of 63.5 Gy (range 35.75-66.6), typically to an initial small pelvis field follow by a tumor boost. 14/15 received chemo with RT. Median TraceIT volume was 0.5cc (range 0.3-0.75) per injection site for 4 (range 4-6) sites per patient for total volume of 2cc (range 2-3). All pts demonstrated 100% visibility of TraceIT on initial simulation CT and day 1 CBCT. TraceIT visibility declined slightly over time, with 91.5% of patients having visible TraceIT by the end of the initial RT phase (usually week 5) and 82.5% by end of the boost phase. For the initial phase, alignment to fiducials over bone anatomy allowed for reduced VH margins (0.67cm vs 1.56cm). For the boost phase, the VH margin was similar between fiducial and bone alignment (1.01cm vs 0.96cm). There have been no acute or late complications from TraceIT placement. There were no grade grade (G) 4/5 toxicities; three pts had acute G 3 events, and three pts experienced late G 3 toxicity: two related to hematuria and one from ureteral stenosis. There were no late G≥2 GI toxicities. No patients have undergone cystectomy. At a median follow-up of 22 months, 2-yr OS was 79.1% and 2-yr PFS was 75.4%. Conclusions: TraceIT is safe and feasible for use in image-guided RT. TraceIT can increase the precision of RT by facilitating accurate target delineation of the bladder tumor bed and daily motion management which may allow for smaller radiation treatment margins to be used to reduce toxicity and to potentially facilitate safe dose escalation to tumor, which can improve tumor control. Clinical trial information: NCT03125226.

End-of-life health care utilization (EOLHCU) in patients with recurrent, metastatic head and neck squamous cell carcinoma (RMHNSCC) treated with immune checkpoint inhibitors (IO)

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Background: Demographic and EOLHCU trends are undefined in the growing population of IO-treated RMHNSCC; we sought to study these in a single institution retrospective study. Methods: We identified 228 RMHNSCC pts who received ≥1 IO dose between 01/2013 and 12/2018; of these, 74 were deceased with accessible EOLHCU data such as advanced care plan documentation (ACPD) or evidence of systemic therapy or ER/hospital/ICU admission within 30 days of death (DOD). Demographic, tumor and treatment data were obtained. Overall survival (OS) was estimated using the Kaplan Meier method; multivariable analysis was performed using a Cox proportional hazards model. In an exploratory analysis, EOLHCU was compared to a cohort of 379 deceased thoracic malignancy (TM) pts using a chi-square test. This project was approved by our institutional IRB. Results: Median pt age was 62 (25 – 90). Most were male (56, 75%), white (60, 81%), current/former smokers (46, 62%); 34 (46%) smoked ≥10 pack years. Common primary sites included the oral cavity (28, 37.8%) and oropharynx (24, 32.4%). ECOG PS at IO initiation was 0 in 15 pts (20%,) 1 in 37 (50%), 2 in 20 (27%), 3 in 1 (1%), and unknown in 1 (1%). Of the 42 (57%) treated off-trial, 18 (42%) had an ECOG ≥ 2. 71 (95%) had prior curative intent therapy. 42 (57%) had distant metastases. Compared to TM, IO-treated RMHNSCC pts were more likely to have ACPD (66% vs. 45% p < 0.01), an ED visit (42.3% vs 19.5%, p < 0.01) and/or a hospital admission (42.3% vs 17%, p < 0.01) within 30 DOD. There was no difference in ICU admissions within 30 DOD (9.9% vs. 8.2%, p = 0.81), ICU deaths (7% vs. 4%, p = 0.4), or systemic therapy within 7 (4.2% vs. 2.4%, p = 0.63), 14 (8.5% vs. 6.6%, p = 0.76) or 30 (25% vs 19%, p = 0.31) DOD. Among IO-treated RMHNSCC pts, multivariable analysis revealed inferior OS with worse PS (ECOG 2-3 vs. 0: HR = 7.76, p = 0.00002, 95% CI = 3.07 - 19.64; ECOG 1 vs. 0: HR = 2.97, p = 0.008, CI = 1.33 - 6.62). OS also decreased with smoking status (current/former vs. never: HR 2.18, p = 0.007, CI = 1.24-3.84). No association was observed between ECOG PS, age or smoking status at IO initiation and any EOLHCU metric. Conclusions: At our center, a significant proportion of deceased, IO-treated RMHNSCC pts had an ECOG PS ≥ 2 and an inferior OS compared to ECOG 0/1. Exploratory comparison with a non-RMHNSCC TM cohort suggests high rates of EOLHCU within 30 DOD despite ACPD, representing an opportunity for supportive care augmentation. Whether EOLHCU differs among IO vs non-IO treated RMHNSCC is unknown and merits further study.

Bladder Cancer Multidisciplinary Clinic (BCMC) model: Impact on imaging, pathology and treatment recommendations

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Background: Despite guideline-based standard of care recommendations in BC and upper tract urothelial carcinoma (UTUC), treatment remains variable across US. Experts recommend focusing BC care in tertiary centers. We hypothesized that a BCMC model, with expert central pathology and radiology review, may result in changes in corresponding reports, and, thus, treatment recommendations. Methods: Our BCMC clinic format includes simultaneous consultation with Urologic, Medical and Radiation Oncology, with real time expert genitourinary pathology and radiology review. We retrospectively assessed the concordance between outside (pre-BCMC) imaging & pathology review and BCMC review. Differences between pre- and post- BCMC recommendations on management were also assessed; descriptive statistics were used. Results: We identified 233 BC/UTUC patients (pts) referred to BCMC. Complete radiographic and pathologic data were available for 209 pts. Median age at time of evaluation was 68 (27-93) and 85% were PS ECOG 0-1. After BCMC review of outside records, 112 (53.6%) imaging and/or pathology changes were noted, with 57 (27%) pts upstaged. Overall, imaging interpretation was changed in 25% of cases, and 20% of pts were upstaged. BCMC pathology review resulted in changes in 59 (28%) pts. Among those, 42 (71%) had histologic subtype addition or change, 9 (15%) had LVI/CIS status change, and 2 (3.4%) had low to high grade conversion. In terms of pathology staging, 7 (12%) were downstaged, and 5 (8.5%) upstaged. Further diagnostic work-up was recommended in 71/209 (34%) pts, resulting in upstaging in 11/71 (15.5%) of cases. Pre- and post- BCMC-recommended treatment modality differed in 55/209 (26%) pts, while a new treatment modality was added in 28/209 (13%) pts. These recommendations were followed 91.4% of the time (191/209 pts). Conclusions: BCMC initiation at our institution resulted in imaging and/or pathology diagnostic changes in almost half of cases, with approximately a quarter of pts being upstaged. Findings reveal the importance of expert radiology and pathology review in BC. Further study is needed to confirm the proposed benefits and impact of BCMC on treatment response and outcomes.

A phase II study of degarelix prior to radiation on prostatic tissue androgens

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Background: Optimizing androgen suppression may provide better treatment outcomes for localized prostate cancer (PCa). Numerous trials have supported the benefit of combining androgen deprivation (ADT) with definitive radiotherapy in men with locally advanced or high-grade disease. LHRH agonist (LHRHa) is most commonly used. The LHRH antagonist degarelix may provide more robust androgen suppression. The impact on tissue androgens following use of degarelix prior to radiation has not been reported. We examined the impact on androgens in serum and tissue after 12 weeks of degarelix in this phase II study. Methods: A prospective, phase II study was conducted in men with localized PCa treated with 6 months of neoadjuvant and concurrent degarelix with radiation. Prostate biopsies were obtained at the time of fiducial placement before radiotherapy. Serum and tissue androgen levels were measured by liquid chromatography-tandem mass spectrometry. Needle biopsies from a separate analysis of untreated men or those receiving LHRHa prior to prostatectomy were used as tissue androgen level controls. Results: 16 men with intermediate (4) and high-risk (12) PCa received study therapy. 14 men completed degarelix and planned radiation to 77.4-81 Gy. Serum and tissue androgens after 12 weeks of therapy are compared to untreated control and LHRHa treated patients (12 weeks). Serum levels of dihydrotestosterone (DHT) and testosterone were similarly suppressed by LHRHa or degarelix compared to untreated controls, without statistically significant differences. Degarelix provided statistically greater reduction in androsterone than LHRHa. Conclusions: In this phase II study degarelix and LHRHa achieved similar serum and tissue androgen levels at 12 weeks; however, there was a greater suppression of tissue androsterone with degarelix. The clinical significance of this difference remains uncertain. Clinical trial information: NCT01731912. [Table: see text]

Patterns of recurrence in patients with sinonasal undifferentiated carcinoma (SNUC) treated with multimodality therapy at a single center

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Background: SNUCs are rare and without established therapeutic standards. This is a retrospective review of therapeutic outcomes in pts with SNUCs treated at our center. Methods: Data was collected retrospectively on pts with a confirmed diagnosis of SNUC treated at the University of Washington Medical Center. Demographic data, tumor/treatment characteristics,and dates of recurrence/progression and death were recorded. The Kaplan Meier method was used to estimate survival outcomes; the log-rank and Wilcoxon tests were used to explore associations of clinical characteristics with outcome. Results: Between 5/1992 and 11/2016, 32 pts were treated, 1 was excluded due to incomplete data. The median age was 52 (range 22-82) years, 14(45%) were female, 26(83%) were white, 17(54%) reported current or former tobacco use. One presented with distant metastases, 1 had T2N0 disease, and all other pts had locally advanced disease. Six pts had nodal involvement on initial staging, and 25 patients had T4 disease. Eleven(35%) pts had no skull base/CNS invasion, 7(22%) had skull base extension up to the cribriform plate, 13(42%) had extension beyond the cribriform plate and into the CNS. Twenty-one(67%) pts underwent surgical resection, 29(93%) underwent radiation(XRT) with a median dose of 70 (range 54-72) Gy, and 28(90%) received cisplatin based chemotherapy, with 24 of these given concurrent with XRT, 19(60%) were treated with surgery followed by chemoradiation. With a median 61 months of follow up, 15 pts have recurred, 10 of these recurrences occurred in local sites, with 6 having intracranial progression, 2 of which were leptomeningeal. The median time to progression was 15 months and median overall survival was 58 months . Any vs no tobacco use (58 vs 35 mo p = 0.8), was not predictive of overall survival. The presence of nodal disease (87 vs 7 mo p = 0.005), and CNS invasion beyond the cribriform plate (NR vs 14 mo p = 0.04) was associated with inferior median overall survival. Conclusions: Local/CNS recurrence was the predominant failure pattern in our pts. CNS invasion beyond the cribriform plate and nodal disease were associated with significantly worse survival.

Randomized phase II trial of cisplatin and radiotherapy with or without erlotinib in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN)

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Background: The combination of cisplatin and radiotherapy is a standard treatment for patients with locally advanced SCCHN. Cetuximab-radiotherapy is superior to radiotherapy alone in this population, validating EGFR as a target. Erlotinib, a small molecule inhibitor of EGFR, has activity in recurrent/metastatic disease. Adding EGFR inhibition to standard cisplatin-radiotherapy may improve efficacy. Methods: Patients with locally advanced SCCHN were randomized to receive cisplatin 100mg/m2 on days 1,22 and 43 combined with 70Gy of radiotherapy (arm A) or the same chemoradiotherapy combined with erlotinib 150mg/day, starting one week prior to radiotherapy and continued to its completion (arm B). Randomizing 204 patients had 80% power to compare a 60% complete response rate (CRR) to a 40% null rate. Available tumors were tested for p16, ERCC1 and EGFR FISH. Results: Between June 2006 and October 2011, 204 patients were randomized. Results presented are based on intention to treat. There were more females on arm A however no other differences in patient characteristics, including p16 positivity. Patients on arm B had more rash and gastrointestinal adverse events, but treatment arms did not differ for rates of other grade III/IV toxicities or serious adverse events (SAEs). Arm A had a CRR of 61% and arm B had a CRR of 68% (p=0.3). With a median follow-up of 23 months, there were only 29 events in the overall survival analysis and 46 in the progression-free survival (PFS) analysis. The 2 and 3 year PFS were 71% and 63% for arm A and 78% and 73% for arm B (p=0.61). Conclusions: The addition of erlotinib did not increase the rate of SAEs but failed to significantly increase CRR. As seen in other recent trials, our results in both arms are superior to historical comparisons. Updated PFS data will be presented. Supported by a grant from the investigator-initiated trial program of Genentech/OSI.

Expression of p16, ERCC1, and EGFR amplification as predictors of responsiveness of locally advanced squamous cell carcinomas of head and neck (SCCHN) to cisplatin, radiotherapy, and erlotinib: A phase II randomized trial

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Background: This study evaluated the expression of p16 and ERCC1 and EGFR amplification as predictive and prognostic factors in a recently completed phase II randomized trial comparing cisplatin (100 mg/m2 on d 1, 22, 43) with radiotherapy (70Gy) +/- erlotinib (150 mg/d during radiotherapy) in locally advanced SCCHN. p16 (HPV surrogate) is a known prognostic factor in oropharyngeal SCCHN, and high ERCC1 expression has been correlated with resistance to cisplatin. EGFR gene copy number may be prognostic in SCCHN and alter response to erlotinib. Methods: Pretreatment formalin-fixed, paraffin-embedded tumor tissue was available for 84/204 patients. EGFR copy number was assessed using Vysis LSI DNA probes, and immunohistochemistry was performed on Leica Bond III machines using Lab Vision ERCC-1 (8F1) and CINtec p16 antibodies. All assays were performed in accordance with manufacturer instructions; all studies were reviewed by a single Pathologist (MA) who was blinded to patient outcome. Logistic regression and Cox regression models fit a treatment arm by marker interaction and tested selected linear contrasts. Results: Efficacy analysis showed no difference in complete response rate (CRR) and progression-free survival (PFS) between treatment arms. However, PFS in both arms was better than historical comparisons, with only 46 events over a median follow-up of 23 months. Positivity in p16 was associated with greater CRR (OR 3.5, p=0.03) and longer PFS (HR=0.38; p= 0.07). The CRR effect was greater for the erlotinib arm (OR 8.1, p=0.01) than for Arm A (OR 1.5, p=0.56). The ERCC1 (+) rate was 46% (39/84).ERCC1 expression above the median was not associated with worse CRR (OR 0.69; p=0.46) or PFS (HR 0.99; p=0.98). Only 4 tumors showed EGFR amplification precluding further analysis. Conclusions: p16(+) tumors had a better outcome, similar to other recent trials, and erlotinib seemed to increase the CRR among p16(+) tumors. ERCC1 expression did not predict chemoradioresistance in this study. EGFR amplification was too rare in the tested population to assess predictive or prognostic value.

Effects of SCH23390 and raclopride on a run-climb-run behavioral task in rats

The present study was designed to compare the putative differential behavioral consequences of treatment with SCH23390 (a selective dopamine D1 receptor blocker) and raclopride (a selective dopamine D2 receptor blocker) by employing a run-climb-run (RCR) behavioral task of different lengths. Rats were trained to traverse an uncovered floor alleyway (150 cm), climb a vertical rope (70 or 130 cm), and run across an upper board (100 cm) to access water for the reinforcement. At doses of 0.05, 0.10 and 0.15 mg/kg administered intraperitoneally 60 min before the behavioral session, both SCH23390 and raclopride significantly increased the total time to complete the tasks in a dose-related fashion. Microstructural analysis on the RCR behavioral performance revealed that the most apparent impairment induced by either drug was observed as the subject shifted motion from the end of the floor alleyway to the rope when hopping or to initiate climbing. However, the motion shift from climbing to running on the upper board was significantly impaired by raclopride, but not by SCH23390. Surprisingly, neither SCH23390 nor raclopride affected the climbing response itself. Running responses on the floor alleyway board were significantly disrupted by raclopride, whereas those on the upper board were significantly disrupted by SCH23390. Deficits induced by both drugs were more profound for the longer compared to the shorter rope, and were most notably shown at the transition area from running to climbing. These data indicate that both dopamine D1 and D2 receptors are involved in the RCR behavior performance. The results also suggest that the cost of motoric demand for behavioral performance is important for evaluating of the effects of drugs blocking dopamine receptors.

Qualifying ELISA data: combining information

With immunoassay or bioassay data, the assay standards often exhibit considerable inter-assay variability. However, the assay controls, which are used to monitor the assay performance and set acceptance criteria, should have no or less interassay variability. In this paper, we develop a mixed-effect calibration model for the assay controls to set new acceptance criteria and qualify the enzyme-linked immunosorbent assay (ELISA) data, which incorporates the interassay variation of assay standards and the nature of the assay controls, and overcomes the problems caused by traditional fixed-effect calibration model.

Capillary electrophoretic determination of apoptosis of HeLa cells induced by trichosanthin

Apoptosis is a distinct mode of cell death that is responsible for deletion of cells in normal tissues; it also occurs in specific pathologic contexts. The observation of apoptosis is very important in the research of cancer and cancer therapy. The traditional observation method of apoptosis was agarose gel electrophoresis, which is depending on the determination of ladder-liking DNA fragments extracted from apoptotic cells. It is time-consuming and low-sensitive. Recently, the sieving capillary electrophoresis has been used to detect apoptosis too. However, the problem of DNA fragments contamination is still existing. Here, we have developed a capillary electrophoresis method that could detect apoptosis of whole cell directly and do not need to extract DNA fragments from cells. Apoptosis of adherent cell HeLa cell of carcinoma induced by cyclophosphamide was used as the model to establish the method. The effluence of medicine concentration on apoptosis of cells was studied in detail. It was also found that the method could detect the change of cells in the early period of apoptosis. The induction of apoptosis of HeLa cell by trichosanthin was determined with the method, and the result of flow cytometry was also proved that trichosanthin could result in apoptosis of HeLa cells.

A note on concordance correlation coefficient

In this note, we first review some recent developments about measures of agreement, which are often required in medicine and other sciences, with focus on differences between these methods. In the last part, we mention five important concerns when using a newly developed concordance correlation coefficient. Our conclusion is that we need to be especially careful when using existing correlation methods and a new correlation method needs to be developed in the future.

Reoperation for recurrent trigeminal neuralgia after microvascular decompression

BACKGROUND

Microvascular decompression (MVD) is an effective technique for those who have trigeminal neuralgia (TN) but cannot tolerate, or show no response to medicine. Though the initial success rate is high, some patients may develop severe recurrent neuralgia, especially after a longer period of follow-up. The efficacy of reoperation needs to be evaluated. To know the possible risk factors of recurrence after initial MVD is mandatory to the management of recurrent TN.

METHODS

Among the 80 cases of TN treated with MVD, five cases showed severe recurrent symptoms within a follow-up period from 9 months-4 years. The symptoms recurred on the same side of the face, and were unresponsive to medical treatment. Brain computed tomography (CT) and magnetic resonance imaging (MRI) may reveal the etiology of recurrence. Repeat decompression of the trigeminal nerve was the main goal of reoperation, which was done via a suboccipital approach.

RESULTS

Over the past 17 years, 80 MVDs for TN have been performed at Chang Gung Memorial Hospital. There were five cases of serious postoperative recurrence, which could not be relieved by medicine. Recurrence occurred 1 day-12 months after the initial surgery. Three cases were due to vascular compression, while two were caused by the local effect of Teflon felt. Reoperation produced complete remission in four patients, and partial remission in one.

CONCLUSIONS

An increasing number of patients may experience severe recurrent TN after initial MVD during a long period of follow-up. Reoperation is safe and beneficial for these patients, but the results are dependent on the etiology of the recurrence. Further vascular compression of the trigeminal nerve can be relieved by MVD. Otherwise, in cases of severe adhesion caused by Teflon, complete microneural lysis can achieve satisfactory results.

A canine model of acute hindbrain ischemia and reperfusion

Animal models of brain stem ischemia are needed for pathophysiological study and evaluation of treatment; few such models are available currently. A new canine model of hindbrain ischemia and reperfusion is introduced in this article. Through an anterior cervical approach, the basilar artery was surgically exposed in 18 dogs. The posterior communicating and superior cerebellar arteries were embolized with cyanoacrylate glue to isolate the posterior circulation from the anterior circulation. Reversible hindbrain ischemia was induced in 14 dogs by the temporary clipping of the vertebral and ventral spinal arteries for various periods (10-30 min), then the clips were removed and reperfusion was achieved for 5 hours. In all 14 dogs, the hindbrain ischemia was confirmed by the decreased perfusion pressure in the basilar artery (< 10 mm Hg), the diminished regional cerebral blood flow as measured with a laser Doppler flowmeter at the medulla oblongata (< 10 ml/100 g/min), the flattened brain stem auditory evoked potentials, and the increased leakage of Evans blue dye from tissue. These parameters did not change in the four control dogs. The changes in brain stem auditory evoked potentials were closely related to the length of ischemic interval; after 10 minutes of ischemia, reperfusion fully reversed the changes in brain stem auditory evoked potentials, but 20-minute and 30-minute ischemic intervals partially or totally depleted the brain stem auditory evoked potentials. Delayed postischemic hypoperfusion occurred in all five dogs that underwent the 30-minute ischemic interval. The early physiological changes in this model allowed us to estimate the severity of brain stem ischemia and the resulting damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Postictal neurogenic pulmonary edema during uncal herniation--a case report and literature review

A 13-year-old boy fell off a tree and developed an acute subdural hematoma (SDH) which was treated conservatively because the patient was fully conscious. After a generalized tonic-clonic seizure, he manifested signs of uncal herniation and neurogenic pulmonary edema (NPE). The patient made a good recovery after craniotomy and evacuation of the SDH with intensive pulmonary care. Though rare, uncomplicated postictal NPE in children almost runs a smooth course with favorable outcomes. However, the mortality rate is high in postictal NPE complicating cerebral herniation, and it seems an exception that our patient made a good recovery.

Serial regional blood flow and visual evoked responses in transient cortical blindness

Normal regional blood flow was documented by Single Photon Emission Computed Tomograms 5 and 20 hours before the full recovery of cortical blindness in two patients, lending itself to the possibility of being a prognostic factor. Rubbing of the posterior cerebral arteries against the tentorial edges during trauma instead of traction was believed to cause blindness in one patient and embolization due to hammering bone grafts home during cervical spinal fusion, in the other. Pattern reversal visual evoked responses (PRVERs) were absent during blindness; upon recovery P 100 with full amplitude and normal latency appeared despite the presence of tunnel vision. These are consistent with the fact that the central 8-10 degrees of visual field represented in the posterior occipital poles being the main sources of P 100 in association with the x-cells in the centre of the retina.

Inhibition of some human neutrophil functions by the cyclooxygenase inhibitor ketorolac tromethamine

Ketorolac tromethamine, a new nonsteroidal anti-inflammatory agent of the pyrrolo-pyrrole group, was assayed for inhibitory effects on polymorphonuclear leukocytes (PMN) in a variety of systems. Ketorolac inhibited PMN superoxide anion generation, lysozyme release, myeloperoxidase release, adherence to plastic surfaces, and chemotaxis in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP) in a dose-dependent manner. Ketorolac also inhibited phorbol myristate acetate-stimulated adherence of PMN to bovine pulmonary artery endothelial cells. The drug inhibited lysozyme and myeloperoxidase release by PMN in response to C5a but failed to inhibit C5a stimulation of PMN in any of the other assays. Levels of ketorolac required to inhibit PMN function in most systems were in the range of 0.2 to 1.0 mg/ml, but chemotaxis to fMLP was inhibited by concentrations of ketorolac as low as 1 microgram/ml. Ketorolac, currently the only nonsteroidal anti-inflammatory drug available in a parenteral form may have therapeutic usefulness in a variety of conditions thought to be mediated in part by PMN, including sepsis.