Stereological estimation of the total number of ventilatory units in mice lungs.

We present an unbiased estimator of the total number of alveolar structures distal to the transition from a bronchiole to an alveolar duct system ('ventilatory units', VUs). In species without respiratory bronchioles, including mice, the number of VUs is equivalent to the number of acini. The acinus is a functional unit of gas exchange, defined as a parenchymal unit distal to a terminal bronchiole in which all airways contain alveoli and thus participate in gas exchange.

Pre-therapeutic (124)I PET(/CT) dosimetry confirms low average absorbed doses per administered (131)I activity to the salivary glands in radioiodine therapy of differentiated thyroid cancer.

Purpose: Salivary gland impairment following high activity radioiodine therapy of differentiated thyroid cancer (DTC) is a severe side effect. Dosimetric calculations using planar gamma camera scintigraphy (GCS) with (131)I and ultrasonography (US) provided evidence that the average organ dose per administered (131)I activity (ODpA) is too low to account for observed radiation damages to the salivary glands. The objective of this work was to re-estimate the ODpA using (124)I PET(/CT) as a more reliable approach than (131)I GCS/US.

Stereological estimates of alveolar number and size and capillary length and surface area in mice lungs.

The major function of the lung is gas exchange and depends on alveolar and capillary parameters such as surface area and volume. The number of alveoli may report on the nature of structural changes in lung parenchyma during development, illness or changing environmental factors. We therefore developed an efficient and easily applicable stereological design for estimating and monitoring these structural parameters in the mouse lung.

Optimized 124I PET dosimetry protocol for radioiodine therapy of differentiated thyroid cancer.

Unlabelled: Iodine kinetics and lesion dose per administered 131I activity (LDpA) of differentiated thyroid cancer metastases were determined using 124I PET. These data were analyzed to derive an optimized dosimetry protocol.

Methods: We evaluated the time-activity-concentration curves of 37 lesions in 17 patients who had undergone thyroidectomies.

124I-PET dosimetry in advanced differentiated thyroid cancer: therapeutic impact.

Purpose: This study evaluated the impact of (124)I-positron emission tomography (PET) dosimetry on post-primary surgery therapy in radioiodine-naïve patients with advanced differentiated thyroid cancer (DTC).

Patients, Material, Methods: In each of 28 thyroidectomized patients with high-risk DTC (one or more of pT4, pN1 or pM1), we gave 23-50 MBq of (124)I as an oral capsule and performed PET dosimetry to calculate the individualized therapeutic (131)I activity that would, insofar as possible, achieve a radioiodine dose >or=100 Gy to all metastases without exceeding 2 Gy to the blood (a surrogate for bone marrow toxicity). We thus determined the absorbed lesion dose per GBq of administered 131I activity (LDpA) based on serial PET (4, 24, 48, 72 and 96 h after oral 124I intake) and PET/computed tomography (25 h after (124)I intake) and the critical blood activity (CBA) based on blood and whole-body radiation counting (2, 4, 24, 48, 72, 96 h after 124I intake).