Pancreas: An Organ-at-Risk to Consider in Future Pediatric Abdominal Radiotherapy

PURPOSE/OBJECTIVE(S)

Irradiation to the pancreas during pediatric radiotherapy is associated with secondary late effects, yet the pancreas is not typically considered an organ-at-risk (OAR) during radiotherapy planning. This audit investigated incidental pancreatic doses to estimate the relative risk (RR) of developing diabetes in later life.

MATERIALS/METHODS

Incidental pancreas doses were audited from 92 patients aged 2 to 19 historically treated with photons for craniospinal irradiation (CSI, N = 73) and for abdominal neuroblastoma (N = 19). Prescription doses ranged 21-36 Gy and 21-39 Gy (with boost to spine up to 50 Gy) for neuroblastoma and CSI patients, respectively. The pancreas was segmented on all planning CT scans following RTOG guidelines. Furthermore, the pancreas was split into its sub-volumes (head, body and tail) for abdominal cases only, since these scans were acquired with contrast enhancement. The RR of developing subsequent diabetes was estimated as a function of dose (D): RR = 1+0.65 × D × exp(-0.3 × D). Dose to the pancreas tail was used for neuroblastoma cases, whereas dose to the whole pancreas was used for CSI patients given that the pancreas could not be split in non-contrast scans.

RESULTS

The mean dose delivered to the whole pancreas was 15.4±7.5 Gy for all patients, 12.7±4.7 Gy for CSI patients and 25.9±7.4 Gy for abdominal patients. Pancreas V10Gy was 61.2% for all patients, 51.5% for CSI, and 98.6% for abdominal patients; V30Gy = 0% in all cases. These doses represented an estimated diabetes RR of 7.3±1.5, 6.6±1.3, and 8.7±0.6, respectively; RR>5 in 88%, 85% and 100% of all patients, CSI and abdominal patients audited, respectively.

CONCLUSION

Current incidental doses were associated with a diabetes RR>5 in all patients treated for abdominal neuroblastoma and the majority who received CSI. These findings suggest the pancreas should be routinely delineated and considered as an OAR in radiotherapy planning. This may help to identify higher risk patients and inform late-effect monitoring during survivorship. Further work in underway to assess if proton therapy could reduce the RR of diabetes particularly in abdominal cases. Improved availability of high-quality imaging during radiotherapy planning, such as contrast administration or planning MRI, is becoming more necessary to accurately delineate subsegments of the pancreas for improved RR estimations.

Development of Population-Based Pediatric Computational Phantoms for Radiotherapy Applications

PURPOSE/OBJECTIVE(S)

Age-specific pediatric computational phantoms are used in radiotherapy (RT) for quality assurance and for reconstruction of historical RT doses (within others). Phantoms are typically developed from healthy patients and may not effectively represent those with cancer due to pathology and/or treatment effects. This study evaluated a set of population-based pediatric computational phantoms developed in-house in terms of anatomical plausibility.

MATERIALS/METHODS

Planning CTs and contours from historical craniospinal irradiation (CSI) patients (n = 74, median age 7y, range: 1-17y) were used to generate and evaluate a set of in-house age-specific population-based RT phantoms (RT-P). The RT-P were generated by combining a sub-set of clinical CTs and contours through groupwise deformable image registration, generating average models of CSI sub-populations (n = 74, median age 7y, range: 3-14y). Models were then compared against clinical data and two libraries of phantoms representing healthy populations: the International Commission on Radiological Protection (ICRP) pediatric reference computational phantoms (n = 8, median age 8y, range: 1-15y) and a variety of default 4D extended cardiac torso (XCAT) phantoms (n = 75, median age 9y, range: 1-18y). Variation between organ volumes for the different datasets was assessed through a linear fit of organ volume with age, reporting the slope (∑) of each fit [y-1]. Average difference between the volume datapoints and the linear fit for clinical data (Δ) [%] were also reported. This allowed for comparisons of the RT-P to clinical and reference data in terms of organ volumes across developmental stages.

RESULTS

The table shows 9 of the 19 investigated organs. The ∑ reported for RT-P models were of similar magnitude as the clinical data and other phantoms, effectively modelling changes with age. The greatest and least ∑ were reported from lungs and thyroid respectively, in agreement with expected relative sizes between organs. Larger values for Δ were likely due to differences in organ filling and segmentation strategy between datasets, limitations of RT-P methodology, and/or anatomical differences between healthy and cancer populations.

CONCLUSION

The RT-P models show promise in representing the RT cohort that may benefit from specialized anatomical phantoms. Further work is needed to address the limitations of the current methodology and its applicability to other RT cohorts.

Surgical Treatment of Cardiac Tumors: a 17-year Experience at Department of Cardiac Surgery, NICVD, Dhaka

Cardiac Myxoma is the most common benign intra-cardiac tumor of heart. We studied its incidence, clinical presentations, short term outcome, morbidity and mortality following surgery over a period of 17 years. The retrospective observational study was performed in the Department of Cardiac Surgery, National Institute of Cardiovascular Diseases (NICVD) Dhaka, Bangladesh from 2000 to 2016. NICVD is the tertiary hospital for cardiovascular surgery in the Government sector. One hundred twenty nine (129) patients were of cardiac myxoma among 11,923 open heart surgery was done in this study period of 17 years. As a result, cardiac myxoma patients represent 1.08% of all open heart surgery. Pre-operative diagnosis was done on clinical presentations and 2D echocardiography, which is the most important tool for its diagnosis. Most of the patients presented at 4th to 5th decade of life. The patients presented with triad of valve obstructive features, embolic symptoms and constitutional symptoms alone or in combination. Among all myxoma patients, majority (86.6%) had left atrial myxoma. Cardiac myxoma forms a very small percentage of all cardiac diseases requiring surgical treatment. Immediate surgical excision is indicated in all patients to avoid life-threatening complications. Outcome of surgical treatment was excellent.

Surgical Management of a Critical Ischemic Mitral Regurgitation Patient

Functional ischemic mitral regurgitation is strongly associated with poor outcomes in patient with coronary artery disease. The best management for mitral regurgitation at the time of coronary revascularization remains controversial. We report, a case of 58 years-old men admitted to GKNM hospital, Coimbatore, Tamil Nadu, India with chest pain and respiratory distress for last 6 hours during my fellowship training in that hospital. ECG showed acute antero-septal MI. The transthoracic echocardiogram revealed severe left ventricular dysfunction with moderate mitral regurgitation. Coronary angiogram revealed triple vessels disease. We planned for early CABG. But the patient suddenly developed severe respiratory distress with ventricular tachycardia. Patient managed with the support of invasive ventilation and IABP. After that, CABG along with mitral valve repair was done under cardiopulmonary bypass. The patient showed excellent symptomatic improvement during his early post-operative period. Mitral valve repair along with CABG may be a preferable treatment option for patient with Ischemic heart disease with moderate mitral regurgitation.

The AutoPap 300 QC System multicenter clinical trials for use in quality control rescreening of cervical smears: II. Prospective and archival sensitivity studies

BACKGROUND

The AutoPap 300 QC System is an automated device for the analysis of conventional cervical cytology slides. The AutoPap selects an enriched population of cases for quality control review. These studies evaluated the overall sensitivity of AutoPap device to a wider variety of cytologic abnormalities than could be analyzed in the prospective portion of the clinical trials.

METHODS

At five clinical trial sites, positive cases were selected from: 1) archives (historic sensitivity study) or 2) current positive cases (current archive sensitivity study). Cases were analyzed by the AutoPap System along with matched negative cases and stratified into detection deciles by instrument score for each diagnostic category.

RESULTS

For the historic sensitivity study, the percentages of cases present within the top 10% instrument scores were as follows: atypical glandular cells of undetermined significance (AGUS): 33.7% (n = 243); low grade squamous intraepithelial lesion (LSIL): 57% (n = 412); high grade squamous intraepithelial lesion (HSIL): 81.6% (n = 385); and carcinoma: 77.7% (n = 139). For the current archive sensitivity study, the percentage of cases within the top 10% of instrument scores were as follows: atypical squamous cells of undetermined significance (ASCUS): 37.6% (n = 205); AGUS: 27.3% (n = 22); LSIL: 53.7% (n = 410); HSIL: 80.7% (n = 202); and carcinoma: 62.5% (n = 8). Sensitivities at higher percentiles proportionately were greater.

CONCLUSIONS

The AutoPap 300 QC System is detection sensitive, particularly at the level of LSIL and greater. When coupled with the data from the prospective intended use study, these results provided confirmation of the instrument's ability to enhance the false-negative detection rate significantly when compared with a 10% random case selection process. In addition, high sensitivities to all categories of abnormality suggest the possibility of using such instrumentation as a primary screening device for cervical cytology.

The AutoPap 300 QC System multicenter clinical trials for use in quality control rescreening of cervical smears: I. A prospective intended use study

BACKGROUND

The AutoPap 300 QC System is an automated device for the analysis of conventionally prepared cervical cytology slides. The AutoPap System selects an enriched population of cases for human quality control (QC) review. The device assigns a score based on the likelihood that a slide is abnormal. Cases are selected for QC rescreening that have scores exceeding a preset threshold corresponding to approximately the top 10% (or greater) of scores.

METHODS

AutoPap false-negative detection, compared with a 10% random QC process, was tested in a 6-center clinical evaluation study. At each site, a block of up to 150 consecutive negative slides (including detected false-negative cases) were selected randomly daily. All slides were run on the AutoPap System and rescreened by cytotechnologists for truth determination. The false-negative cases included in the top 10% group selected by AutoPap System then were compared with false-negative detection by the random selection process.

RESULTS

Fourteen thousand nine hundred fourteen cases were analyzed. The AutoPap-enriched 10% quality control group contained false-negative cases at rates 3 to 5 times that of the random selection method (P < 0.01). The sensitivity for all false-negative cases was 35% and was 52% for false-negative cases at the level of low grade squamous intraepithelial lesion and higher.

CONCLUSIONS

The AutoPap 300 QC System provides the potential for a marked increase in the number of false-negative cervical cytology cases that can be detected on QC rescreening. A significant reduction in laboratory false-negative rates can be expected if this device is utilized in routine practice.

Fine needle aspiration cytology of an ectopic parathyroid adenoma: a case report

BACKGROUND

Surgical exploration in the region of the neck identifies a majority of parathyroid adenomas; however, in individuals in whom surgical exploration has failed, fine needle aspiration (FNA) biopsy can be useful. Ectopic parathyroid adenomas can be rapidly diagnosed by the cytologic appearance of aspirate smears with the identification of stromal and intracellular lipid on oil red O-stained smears.

CASE

A 59-year-old male presented with hyperparathyroidism; surgical exploration of the neck in the region of the thyroid gland failed to identify any parathyroid abnormality. Subsequent imaging with (99m)technetium and (201)thallium showed a mass in the left supraclavicular region that, on FNA biopsy, was confirmed as an ectopic adenoma. Removal of the adenoma resulted in normal serum calcium levels.

CONCLUSION

FNA can be successfully utilized in the localization of ectopic parathyroid tissue.

Mediastinal needle biopsy. A 15-year experience with 139 cases

BACKGROUND

Radiologically guided needle biopsy and cytologic evaluation provide a reliable method of diagnosis for planning definitive therapy of patients with mediastinal lesions.

MATERIALS AND METHODS

In this retrospective study of one of the largest series from a single institution, 141 consecutive mediastinal needle biopsies from 139 patients were reviewed during a 15-year period.

RESULTS

Adequate material was obtained with a diagnosis achieved in 128 cases (92%). Of these, 33 cases (26%) had benign diagnoses; the remaining 95 (74%) had malignant diagnoses, including 81 carcinomas, 3 sarcomas, 8 lymphoproliferative lesions, 2 malignant germ cell tumors, and 1 malignant thymoma. All benign cases were diagnostically confirmed, and 94 of 95 malignant cases were classified correctly. The only discrepancy that occurred involved a malignant lymphoma diagnosed as a malignant germ cell tumor. Of the 13 inadequate samples, the major category included a nodular sclerosis variant of Hodgkin's disease (4 cases), 1 case of thymoma, 1 case of tuberculous lymphadenitis, and 7 cases for which no follow-up data were available.

CONCLUSION

Needle biopsy is reaffirmed as a reliable and sensitive diagnostic tool for mediastinal lesions, with an overall cytologic diagnostic accuracy of 99% with adequate material. Sclerotic lesions may pose a limitation to this technique and require generous sampling before a more invasive diagnostic procedure is undertaken.

Cytologic and immunohistochemical diagnosis of neuroendocrine (Merkel cell) carcinoma in cerebrospinal fluid

Neuroendocrine (Merkel cell) carcinoma of the skin is a rare entity. Often locally aggressive, this lesion may also metastasize to organ systems, including bone, liver, and brain. The authors report a case of a 64-year-old male who presented with hoarseness and dysphagia 17 months after resection of a primary Merkel cell carcinoma of the nose. Additional studies revealed bilateral vocal cord paralysis secondary to central nervous system dysfunction. Cytologic evaluation of the cerebrospinal fluid revealed malignant tumor cells consistent with metastatic Merkel cell carcinoma. Presented are the cytologic and immunohistochemical findings in a case of metastatic Merkel cell carcinoma involving the central nervous system.

Aspiration biopsy of the kidney. Simultaneous collection of cytologic and histologic specimens

Aspiration biopsy of mass lesions of the kidney is a diagnostic procedure whose potential benefit to patients with equivocal radiologic findings, suspected metastases, palpable flank masses, nonfunctioning kidneys and even cortical cysts has not been fully explored. Over the past 7 years 163 renal aspiration specimens from 152 patients have been examined. Diagnostic yield was enhanced by use of modified "fine" needles with notched tips so that tissue fragments for histology as well as smears for cytology were obtained in 89% of solid tumors. The availability of aspirated tissue contributed significantly to pathologic classification and often spared patients additional surgery for confirmation of the cytologic diagnosis. Among the 152 cases, there were 35 with renal cell carcinomas, a sufficient number for detailed semiquantitative evaluation of their cytologic features. The remaining cases comprised metastatic carcinomas, lymphomas, transitional cell carcinomas, oncocytomas, cortical cysts, and miscellaneous conditions, e.g., abscesses, nonfunctioning kidneys, and hematomas. Overall, the aspiration biopsy determined the nature of the renal mass in 141 cases (93%). False-negative interpretations were due to insufficient diagnostic material in all but one instance. There was one false-positive result.