Changes In Gland Volume Research Articles

Proton Therapy Specific Salivary Gland Volume Changes After Head and Neck Radiotherapy

Salivary glands are exquisitely sensitive to radiotherapy. Patients treated with radiotherapy to the head and neck region commonly develop salivary gland volume loss and associated xerostomia. Salivary volume loss is associated with salivary function loss, making it a useful surrogate indicator of xerostomia. Previous studies have correlated the degree of salivary gland volume loss with mean radiation doses in patients undergoing photon head and neck radiation. However, change in salivary gland volume relative to radiation dose has not been evaluated in patients undergoing proton therapy. Currently, a constant value of 1.1 is used to relate physical dose (PD) to biological dose (BD) for proton therapy. However, specific tissues may respond differently and thus require a different PD to BD conversion. Herein, we evaluate changes in salivary gland volumes relative to radiation dose in head and neck cancer patients receiving proton therapy to examine the validity of current PD to BD conversions for head and neck salivary glands.Dosimetric data and pre-radiation parotid gland and submandibular gland (SMG) volumes were collected for 20 head and neck cancer patients that received proton therapy at our institution between 2018-2020. Pre-radiation volumes of the SMGs and parotids were collected from treatment planning scans. Post-treatment salivary gland volumes were contoured on 3-month post-treatment diagnostic scans. Mean doses to the glands were gathered from dose-volume histograms generated from treatment plans. Linear logistical regression was performed to measure the effect of dose on volume change.Volume changes of 27 parotids and 38 SMGs were evaluated. Mean doses were 10.0 Gy (standard deviation (SD) 13.2) and 25.2 Gy (SD 25.0) for parotids and SMGs, respectively. Mean dose was < 1 Gy, < 30 Gy, and < 50 Gy in 59.3%, 92.6%, and 100% of parotids compared to 39.5%, 55.3%, and 81.6% of SMGs, respectively. Mean ratios of gland volumes at 3 months post-treatment relative to pre-treatment were 0.962 (SD 0.210) and 1.106 (SD 0.273) for parotids and SMGs, respectively. Effect of mean dose on gland volume change was not statistically significant for either parotids or SMGs.The greater relative size reduction in parotids versus SMGs was consistent with previous photon data. The mean increase in SMG volume could represent post-treatment functional compensation in preserved glands, but this requires additional investigation. Also, determination of the effect of proton dose on salivary gland volume change requires further analysis. Currently, no conclusions can be drawn whether salivary glands are equally or differentially sensitive to proton therapy relative to photon therapy.

Self-channel-and-spatial-attention neural network for automated multi-organ segmentation on head and neck CT images

Accurate segmentation of organs at risk (OARs) is necessary for adaptive head and neck (H&N) cancer treatment planning, but manual delineation is tedious, slow, and inconsistent. A self-channel-and-spatial-attention neural network (SCSA-Net) is developed for H&N OAR segmentation on CT images. To simultaneously ease the training and improve the segmentation performance, the proposed SCSA-Net utilizes the self-attention ability of the network. Spatial and channel-wise attention learning mechanisms are both employed to adaptively force the network to emphasize the meaningful features and weaken the irrelevant features simultaneously. The proposed network was first evaluated on a public dataset, which includes 48 patients, then on a separate serial CT dataset, which contains ten patients who received weekly diagnostic fan-beam CT scans. On the second dataset, the accuracy of using SCSA-Net to track the parotid and submandibular gland volume changes during radiotherapy treatment was quantified. The Dice similarity coefficient (DSC), positive predictive value (PPV), sensitivity (SEN), average surface distance (ASD), and 95% maximum surface distance (95SD) were calculated on the brainstem, optic chiasm, optic nerves, mandible, parotid glands, and submandibular glands to evaluate the proposed SCSA-Net. The proposed SCSA-Net consistently outperforms the state-of-the-art methods on the public dataset. Specifically, compared with Res-Net and SE-Net, which is constructed from squeeze-and-excitation block equipped residual blocks, the DSC of the optic nerves and submandibular glands is improved by 0.06, 0.03 and 0.05, 0.04 by the SCSA-Net. Moreover, the proposed method achieves statistically significant improvements in terms of DSC on all and eight of nine OARs over Res-Net and SE-Net, respectively. The trained network was able to achieve good segmentation results on the serial dataset, but the results were further improved after fine-tuning of the model using the simulation CT images. For the parotids and submandibular glands, the volume changes of individual patients are highly consistent between the automated and manual segmentation (Pearson’s correlation 0.97–0.99). The proposed SCSA-Net is computationally efficient to perform segmentation (sim 2 s/CT).

Levothyroxine use and thyroid gland volumes in children with autoimmune thyroiditis: a systematic review and meta-analysis

Background Autoimmune thyroiditis may manifest as overt hypothyroidism, subclinical hypothyroidism, euthyroidism, or hyperthyroidism in children. Although there is no consensus on treating euthyroidism and autoimmune thyroiditis in children, some studies have demonstrated the efficacy of levothyroxine in reducing thyroid volume, improving thyroid function, and stabilizing the immunological process.&#x0D; Objective To determine the effect of levothyroxine on thyroid gland volume changes, thyroid function, and thyroid antibodies in euthyroid children with autoimmune thyroiditis.&#x0D; Methods We performed a literature search of electronic databases (the Cochrane Library, MEDLINE, EBSCO, ProQuest, clinicaltrials.gov, and other sources, as well as a non-electronic search (searching journals and conference proceedings by hand) to identify studies of euthyroid children with autoimmune thyroiditis published by August 2018. Only English-language articles were included in the search (electronic and non-electronic). Randomized controlled trials that compared levothyroxine with a control (placebo or no treatment) in euthyroid children with autoimmune thyroiditis were selected. The outcome measures were thyroid volume changes, thyroid function, and thyroid antibody levels in euthyroid children with autoimmune thyroiditis. Two authors independently extracted the data, assessed the risk of bias, and analyzed the pooled data from the included studies using a random effects model. The same authors performed a sensitivity analysis.&#x0D; Results We identified 57 studies. Of these, three studies, involving 97 subjects (51 subjects in an intervention group and 46 subjects in the control group) were selected for inclusion in a systematic review/meta-analysis. The meta-analysis revealed a significant difference in mean thyroid volume changes between the two groups (-1.10 SDs; 95%CI -1.56 to -0.64; P&lt;0.0001; I2=6%). The mean difference in the thyroid-stimulating hormone (TSH) change of the two groups was -1.82 mU/L (95%CI -3.52 to -0.11; I2=87%; P=0.04). The standardized mean difference in free thyroxine (fT4) change of the two groups was 0.82 pmol/L (95%CI -1.14 to 2.78; I2=89%; P=0.41).&#x0D; Conclusion In euthyroid children with autoimmune thyroiditis, levothyroxine treatment reduces the thyroid volume better. The TSH level change in the intervention group is better than those in the control group. Levothyroxine treatment did not significantly improve free T4.

A prospective study of weekly intensity modulated radiation therapy plan adaptation for head and neck cancer: improved target coverage and organ at risk sparing.

This prospective study of weekly CT scanning and plan adaption during H&N IMRT reports on the frequency of plan adaptations based on dosimetric differences between original and re-optimised IMRT plans. The volumetric and geometric change occurring in target volumes and salivary glands is also described. Ten H&N cancer patients underwent weekly planning CT imaging and re-optimisation of the IMRT plan if PTV or OAR coverage was unacceptable. Comparisons of PTV and parotid gland dosimetry between the original and adaptive plans were made. Parotid and submandibular gland volume changes and shift were calculated. Eight of ten patients required one or more plan adaptations, with 41% of adaptations occurring by fraction ten. Salivary glands reduced in volume, with a medial shift of the lateral border of the parotid gland and a superior shift of the submandibular gland. Change in PTV coverage did not correlate with weight loss or nutritional score. Inadequate PTV coverage, requiring plan adaptation, occurs early in the course of IMRT. A weekly Adaptive RT (ART) protocol results in significant improvement of PTV coverage. Implementation of a clinical ART protocol should include imaging and dose calculation within the first ten fractions.

Does the Pituitary Gland Volume Change in Polycystic Ovary Syndrome?

Aims: Polycystic ovary syndrome (PCOS) is the commonest cause of menstrual irregularity and hirsutism during reproductive age. We hypothesized in the alterations in the pituitary gland in PCOS. Methods: We measured the volume of the pituitary gland in 39 PCOS patients and 42 age-matched healthy controls using 0.35 mm thick T1-weighted sagittal cranial images. Serum levels of estradiol (E2), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured on days 3–5 of the menstrual cycle of the participants. Results: There was a significant difference in terms of LH, FSH, and LH/FSH ratio (p < 0.05) between groups. Mean pituitary gland volume (PGV) was 4.1 ± 1.36 mm³ for the study group and 3.4 ± 0.77 mm³ for the control group. PGV was statistically significantly higher in PCOS group than the control group (p < 0.05). There was no correlation between hormone levels and PGVs in groups. Conclusion: Enlarged pituitary volume in PCOS may be due to excessive LH release.

Correlation of Salivary Gland Dose to Volume Changes Noted During Adaptive Replanning of Head and Neck Radiation Therapy

Salivary gland shrinkage is known to occur with radiation therapy (RT) for head and neck cancer. Adaptive Radiation Therapy (ART) is commonly performed during the course of Intensity-Modulated Radiation Therapy (IMRT) due to weight loss and/or tumor shrinkage. Our goal was to investigate changes in parotid (PG) and submandibular gland (SMG) volumes measured on initial and replanning CT. We hypothesize that dose received by gland at the time of replan predicts for quantitative gland volume reduction. Replanning thus has the potential to reduce this effect which ultimately may reduce severity of xerostomia. We analyzed 100 patients who underwent adaptive re-planning (200 plans) between December 2014 to August 2017. Volumetric Modified Arc Therapy (VMAT) based IMRT was used in all. All patients had an initial CT simulation scan (Plan 1) used for radiation planning and a subsequent new CT simulation for adaptive replan (Plan 2). Dose-volume histograms were used to measure mean and maximum doses to right and left PG and SMG. We then correlated these doses to PG and SMG volume changes noted at the time of replan (PG1-PG2; SMG1-SMG2). Univariate and multivariate analyses were performed to identify factors contributing to gland volume changes. Tumor site included 9 oral cavity, 50 oropharynx, 14 Larynx, 7 Nasopharynx, and 20 others. Treatments were definitive chemo-RT in 67%, adjuvant chemo-RT in 20%, or adjuvant RT alone in 10%. Chemo used was Cisplatin-based 36%, Carboplatin-based 22%, or Cetuximab-based in 28%. Median total RT dose was 70 Gy (60-70 Gy in 30-35 daily fractions). Median time to performing replan was at fraction #21 (42 Gy) and around day 37 of therapy (13-66 days). Mean weight loss at time of replan was -4.3% (-21.3 to +17.5%). Analysis included 181 PG and 116 SMG. Mean dose received at time of replan with corresponding volume change: RPG = 1548 cGy, -13.6%; LPG = 1647 cGy, -14.6%; RSMG = 3359 cGy, -12.7%; LSMG = 3366 cGy, -14.4%. The correlation values of dose received and volume change: RPG r = 0.17, LPG r = -0.21, RSMG r = -0.33, and LSMG r = -0.27 (all with P<.05 except RPG, P=.13). Anatomic changes during radiation can result in increased doses to normal tissues and increased risk of toxicity. Our results show a significant change in gland volume in 3 of 4 salivary glands at the time of replanning with a direct correlation to dose received to the gland. Adaptive replan has the potential to reduce salivary gland doses.

Lacrimal Gland Volume Changes in Unilateral Primary Acquired Nasolacrimal Obstruction.

To investigate whether unilateral primary acquired nasolacrimal duct obstruction (PANDO) causes Schirmer score and lacrimal gland volume changes in the contralateral non-PANDO eye. Sixteen unilateral female PANDO and 16 female controls were enrolled in the study. Exclusion criteria were orbital trauma, inflammation, infection, tumor involvement or infiltrative diseases, history of ocular surgery, ocular surface disorder, systemic drug use that interferes with tear secretion, and chronic use of topical eye drops. Bilateral lacrimal gland volumes were measured in computed tomography (CT) images of the participants. A Schirmer test without anesthesia was also performed on each participant. As there was no significant difference between the right and left eye values for Schirmer and gland size (P > 0.05), both eyes of the control group were enrolled in the study. The groups were age matched and the mean lacrimal gland was 0.479 cm3 in the PANDO as well as the contralateral non-PANDO side, which was statistically smaller compared to the control eyes (0.580 cm3) (P = 0.04). The mean Schirmer scores in the same order were 18.5 ± 7.1 mm, 13.2 ± 8.9 mm, and 21.3 ± 10.5 mm, respectively. Non-PANDO side Schirmer scores were lower compared to the other two groups, but statistical significance was present for the control group (P = 0.04). Compared to the control group, lacrimal gland volumes were bilaterally smaller in unilateral PANDO patients. Schirmer scores were statistically lower in the contralateral non-PANDO side compared to the controls.

Radiologic Measurement of Submandibular Gland Ptosis

Ptosis of the submandibular glands is a well-recognized yet poorly quantified element of the aging face and neck. The goal of this study is to describe and quantify the rate and extent of age-related submandibular gland ptosis. A novel grading system is proposed to quantify the degree of descent of the submandibular gland in relation to the inferior border of the mandible. Implications for facial rejuvenation surgery are discussed. Retrospective review. Consecutive computed tomography (CT) imaging studies performed at a university-affiliated hospital were selected for review. Using cross-referenced images in the coronal and axial planes, distance measurements were obtained from the bottom of the submandibular gland to the plane of the inferior border of the mandible. These data points were plotted against subject age for statistical analysis. The position of the submandibular gland was then categorized as grade I when distance below the mandible was < 20 mm, grade II for 20 to 25 mm, grade III for 25 to 30 mm, and grade IV for > 30 mm. Volumetric analysis was performed in a subset of subjects to assess for the possibility of age-related submandibular gland volume changes as a potential confounding factor in distance measurements. One hundred consecutive CT imaging studies were selected for review (50 men, 50 women). A statistically significant linear relationship was identified between subject age and ptosis of the submandibular gland (r = 0.52, p < 0.001), as measured by the distance from the bottom of the submandibular gland from the plane of the inferior border of the mandible. The average rate of descent was 0.17 mm per year. Overall, the position of the submandibular gland was categorized as grade I in 18% of patients, grade II in 27% of patients, grade III in 32% of patients, and grade IV in 23% of patients. No statistically significant gender differences were identified in any of the data points. Volumetric analysis did not demonstrate any age-related changes in submandibular gland volume, and as such, this was excluded as a potential confounding factor in distance measurements. A linear relationship exists between patient age and submandibular gland ptosis, as measured by the distance of the gland from the inferior border of the mandible. To our knowledge, this is the first quantification of the rate and extent of submandibular gland ptosis. A novel grading system for submandibular gland ptosis has been proposed.

Volume changes in remnant thyroid tissue after thyroidectomy in Graves disease.

Surgery is one of the treatment choices for Graves disease. The residual thyroid tissue may shrink or become larger. The object of this study was trying to find out what factors affect the residual thyroid gland volume change after thyroidectomy in Graves disease. We followed thyroid volume changes by ultrasonography in 101 patients with Graves disease who underwent one side lobectomy and another side subtotal thyroidectomy from 1996 to 2006. These patients were divided into three groups according to the residual thyroid size increasing, no change in size, and shrinking. We checked the factors as follows: age, body weight, thyroid-stimulating hormone (TSH) level, TSH-receptor antibody level, anti-thyroid peroxidase (TPO) antibody level, total thyroid volume before and after thyroidectomy, and degree of lymphocyte infiltration. We found that young age and lower residual volume ratio were the most powerful two factors affecting remnant thyroid gland volume changing. We also found that there is no significant correlation between TSH levels and thyroid volume change, nor TSH-receptor antibody titer or thyroid volume change. Age and residual volume ratio were the most powerful two factors in this study.

The relationship between adrenal gland morphometric changes and postmortem interval in rats: A stereological study

The importance of determining time of death is crucial to forensic cases. The ability to use adrenal gland volume changes and adrenal medulla chromaffin cell counts to obtain the postmortem interval was examined in this study. A total of 15 rats were sacrificed by cervical dislocation and divided into three groups. The left adrenal glands were quickly excised in the first group at 0 h, in the second group at 12 h and in the third group at 24 h. Subsequently, the samples were fixed in 10% formalin solution and embedded in paraffin according to standard procedures. Ten to fifteen sections were obtained from each left adrenal gland by taking 30 μm thick sections; then, the sections were stained with hematoxylin-eosin (HE). The adrenal cortex and medullar volumes were calculated by Cavalieri's principle, which is a stereological method. The adrenal medullary chromaffin cell count was evaluated by the optical fractionator method. The total volume of the adrenal gland was determined as 4.82±1 mm(3) at 0 h, 6.32±0.28 mm(3) at 12 h and 8.35±1.73 mm(3) at 24 h. Increases in the adrenal cortex, adrenal medulla and the total volume of the adrenal gland at 12 and 24 h postmortem compared with at 0 h were statistically significant (p<0.05). The difference between the groups in terms of the total number chromaffin cells was statistically significant (p<0.05). In this preliminary study, we evaluated the total volume of the adrenal gland and the number of chromaffin cells of the adrenal medulla. We concluded that these parameters could be used reliably in determining the postmortem interval.

SU‐E‐T‐42: Changes in Submandibular Gland Volume during Radiotherapy

Purpose: To examine submandibular gland volume changes by CT throughout the course of Intensity Modulated Radiation Therapy treatment for head and neck cancers. Method and Materials:CT images from 15 patients were analyzed to evaluate the change in volume of the left and right submandibular glands over the course of treatment (30–35 fractions). Each patient had received daily CT imaging using a CT‐on‐rails unit. Eleven of these patients had pre‐ and post‐treatment measurements of the stimulated and unstimulated saliva flow. Submandibular gland contours were drawn on the first fraction CT. The contours were then deformably mapped to the weekly CTs using an in‐house deformable registration tool. The volume of each gland was extracted, and changes in volume assessed. The changes in gland volume were compared with saliva flow measurements using using the R2 value from a linear fit. Results: All 15 patients showed decreases in gland volume over the course of treatment. The mean gland volume at the start of treatment was 10.6cc (range: 6.9–16.4cc). The mean volume reduction was 32.8% (range: 10.8 – 46.6%), 3.6cc (1.3 – 5.6cc). There was no clear statistical correlation between gland volume decrease and either stimulated or unstimulated salivary function. Conclusions: This study shows a significant reduction in submandibular gland volume over the course of radiation therapy. A more thorough study should be conducted to try and link gland volume decrease with saliva production.

Evaluation of radiation-induced changes to parotid glands following conventional radiotherapy in patients with nasopharygneal carcinoma

Xerostomia is a common post-radiotherapy (post-RT) complication in nasopharyngeal carcinoma (NPC) patients. This study evaluated the relation of post-RT parotid gland changes with the dose received. Data from 18 NPC patients treated by radiotherapy between 1997 and 2001 were collected. Parotid gland volumes were measured and compared between their pre-RT and post-RT CT images; both sets of CT were conducted with the same scanning protocol. Doppler ultrasound was used to assess the haemodynamic condition of the glands after radiotherapy. Doppler ultrasound results were compared against 18 age-matched normal participants. A questionnaire was used to evaluate the patients' comments of xerostomia condition. Radiotherapy treatment plans of the participants were retrieved from the Eclipse treatment planning system from which the radiation doses delivered to the parotid glands were estimated. The correlations of parotid gland doses and the post-RT changes were evaluated. The post-RT parotid glands were significantly smaller (p<0.001) than the pre-RT ones. They also demonstrated lower vascular velocity, resistive and pulsatility indices (p<0.05) than normal participants. The degree of volume shrinkage and subjective severity of xerostomia demonstrated dose dependence, but such dependence was not definite in the haemodynamic changes. It was possible to predict the gland volume change and subjective severity of xerostomia based on the dose to the parotid glands for NPC patients. However, such prediction was not effective for the vascular changes. The damage to the gland was long lasting and had significant effects on the patients' quality of life.

No pituitary gland volume change in medication-free depressed patients

Increased serum cortisol levels and a hyperactive hypothalamo-pituitary-adrenal (HPA) axis have been proposed to play an important role in the pathophysiology of Major Depressive Disorder (MDD). However, there are inconsistent results regarding pituitary gland volume (PGV), which is one of the key elements of the HPA axis evaluated by MRI in depressed patients. In this study, we analyzed the PGV of medication-free moderately depressed MDD patients ( N = 34) and age and sex matched healthy controls ( N = 39). PGV did not differ between MDD patients and healthy controls [mean volume ± S.D.; 0.76 ± 0.17 cm 3 and 0.75 ± 0.14 cm 3; ANCOVA, F 1,69 = 1.25 p > 0.05; respectively]. Our results confirm that volumetric PGV changes are not crucial for depression pathophysiology among unmedicated, moderately depressed adults.

Megavoltage CT assessment of salivary gland volume changes over a standard course of head and neck radiotherapy

Megavoltage CT assessment of salivary gland volume changes over a standard course of head and neck radiotherapy

Neoadjuvant androgen deprivation and prostate gland shrinkage during conformal radiotherapy.

The shrinking effect of 3-month neoadjuvant androgen deprivation (NAD) on preradiotherapy prostate gland volume is well documented. However, recently, it has been shown that the cancerous prostate gland keeps shrinking up to 12 months after NAD start. Thus, if such a reduction is not taken into account, a larger than planned portion of the surrounding normal tissues might shift in the high-dose region during conformal radiotherapy (3DCRT) course. The present study was undertaken to quantify this issue. Prostate gland volume reduction between planning CT (plCT) and the last week of 3DCRT (tmtCT) was prospectively assessed in 33 consecutive patients with localized prostate carcinoma. The median time interval between plCT and tmtCT was 2.5 months (2.1-2.7 months). A single observer was asked to draw on each slice prostate gland volume as appropriate. The observer was 'blind' to the timing of CT (plCT vs. tmtCT). In order to estimate intra-observer variability, prostate gland delineation was repeated twice for each data set. Mean prostate gland change, plCT and tmtCT cumulative dose volume histogram (DVH) calculations for the rectum were analyzed for each patient. Results were correlated to AD status and its duration before plCT. Means were compared by non-parametric rank tests. Based on an internal protocol, 14 patients (42%) did not receive AD, while 19 patients (58%) had undergone neoadjuvant and concomitant AD. The median duration of AD before plCT ranged from 0.2 to 6 months (median: 2.9 months). Although individual data were highly variable, compared to plCT volume, mean prostate gland volume change at the end of 3DCRT was similar for patients receiving (-7.3%) or not (-7%) androgen deprivation (P=0.77). However, within the group of patients treated with hormones, patients starting AD within 3 months from plCT had a significantly larger reduction in prostate volume (-14.2%) than patients with longer NAD duration (-1.1%, P=0.03). At tmtCT, on average, patients undergoing 3DCRT within 3 months from AD start showed an increase of the amount of rectum receiving 40-75 Gy compared to plCT values. At 40 Gy (V40) the mean difference between tmtCT and plCT was +7.5%. In the other two groups, average variations of V40-70 were within +/-2% of plCT values. However, these differences are not significant. For patients who undergo plCT and 3DCRT shortly after AD start, prostate gland shrinkage may be substantial. In some of these patients, this might lead to an unexpected increase of the percentage of rectal wall exposed to intermediate doses.

Neoadjuvant androgen deprivation and prostate gland shrinkage during conformal radiotherapy

Purpose: The shrinking effect of 3 month neoadjuvant androgen deprivation (AD) on preradiotherapy prostate gland volume is well documented. However, recently, it has been shown that the cancerous prostate gland keeps shrinking up to 12 months after AD start. Thus, if such a reduction is not taken into account, a larger than planned portion of the surrounding normal tissues might shift in the high-dose region during 3DCRT course. The present study was undertaken to quantify this issue. Materials and Methods: Prostate gland volume reduction between planning CT (plCT) and the last week of 3DCRT (tmtCT) was prospectively assessed in 33 consecutive patients with localized prostate carcinoma. The median time interval between plCT and tmtCT was 2.5 months (2.1-2.7 months). A single observator was asked to draw on each slice prostate gland volume as appropriate. The observator was “blind” to the timing of CT (plCT vs tmtCT). In order to estimate intraobserver variability, prostate gland delineation was repeated twice for each data set. Mean prostate gland change was analyzed for each patient. Results were correlated to AD status and its duration before plCT. Means were compared by T test. Results: Based on an internal protocol, 14 patients (42%) did not receive AD, while 19 patients (58%) had undergone neoadjuvant and concomitant AD. The median duration of AD before plCT ranged from 0.2 to 6 months (median: 2.9 months). Although individual data were highly variable, compared to plCT volume (100%), mean prostate gland volume change at the end of 3DCRT was similar for patients receiving (92.7%) or not (93%) androgen deprivation (p=0.94). However, as shown in the table, the reduction in prostate volume was significantly larger in the group of patients starting AD within 3 months from plCT compared to the other two pooled groups (p=0.04). PICT and tmtCT cumulative dose volume histogram calculations for the rectum will also be analyzed and shown. Conclusion: For patients who undergo plCT and 3DCRT shortly after AD start, prostate gland shrinkage may be substantial; whether this impacts rectal DVH will be investigated. Tabled 1Androgen deprivationSubgroup# pts% change95% CINo1493.084.9 ÷ 101.1Yes0.2–2.9 months985.878.0 ÷ 93.7Yes3–6 months1098.991.2 ÷ 106.5 Open table in a new tab

Histometry of normal thyroid in man.

Thyroids that did not show any histopathological evidence of disease were collected at necropsy from 107 patients who did not have any history of endocrine disease. Thyroid volume increases with age during childhood and adolescence, remains stable in younger adults, and declines in older subjects. There was no simple mathematical function relating thyroid volume with age: robust smooth curve fitting, however, permitted objective assessment of the age changes. The volume proportion (Vv) measurements of the various histological components did not show any important change with age, but the measurements of volume of these components reflected the gland volume changes with age. The total number of acini in the gland did not show any great age changes, and so it was concluded that the volume changes were a consequence of changes in the size of the individual acini. Measurements of internal and external surface area of the acini showed an increase in childhood and adolescence and decline in older age: unlike the other measurements reported in this paper, however, the surface area measurements must be considered as relative because of the Mandelbrot effect. The prevalence of microscopic nodules in otherwise normal thyroids increased in older patients.