Changes of tumor and normal structures of the neck during radiation therapy for head and neck cancer requires adaptive strategy

The treatment period over which radiation therapy is administered extends over several weeks. Since tumor shrinkage in response to radiation therapy and weight loss due to radiation-induced mucositis may impact on the dose distribution in both target and organ at risk in patients with head and neck cancer, the anatomical changes of tumor and neck volumes during this period should be taken into consideration. We investigated the anatomical changes that occurred in the target and normal structure of the neck during radiation therapy for pharyngeal cancer, and evaluated the necessity of an adaptive strategy. Ten patients with pharyngeal cancer who underwent radical chemoradiation therapy using 3-dimensional conformal radiation therapy RT (66-70 Gy in 33-35 fractions) between April 2009 and September 2010 were enrolled in the study. Patients underwent CT scans every week during their course of treatment. We analyzed the CT data in the radiation treatment planning system and measured changes of tumor, organ at risk, and neck volume. Gross tumor volume (GTV) was rapidly reduced by 28% of the original volume on average in the first 3 weeks. The right and left submandibular glands volume decreased to 70% and 63% of their initial volumes on average, respectively. The volume of the neck in the radiation fields decreased to 89% of its initial volume on average by the sixth week mainly caused by body weight loss due to acute radiation morbidity. Considerable anatomical change in the radiation filed that will affect dose distribution of the target and organ at risk was observed during radiation therapy for head and neck cancer

P-NETG2に対しPRRTを施行した4例に関する検討

In June 2021, 177Lu-oxodotreotide, a PRRT, was approved by insurance for unresectable or recurrent NETs. We investigated the efficacy and safety of PRRT in four patients with P-NETs at our hospital. All patients were confirmed to be positive for somatostatin receptors by using octreoscan. PRRT treatment was then performed and retrospectively evaluated for efficacy and safety. PRRT was administered as lutetium oxodotreotide（177Lu） at 7.4 GBq per dose over 30 - minutes for up to 1 - 4 doses at 8 - week intervals. Efficacy was evaluated using RECIST v1. 1. Adverse effects were evaluated by CTCAE（v5.0 JCOG）. The mean patient age was 60±12.0 years, and all patients were male. Three patients had a PS of 0, and one patient had a PS of 1 or higher. Metastatic organs were the liver in four patients and intra-abdominal lymph nodes in one patient, all of whom were Stage IV. Three patients underwent transarterial embolization. 177Lu-DOTATOC PRRT was administered every 8 weeks, and a total of four courses were administered in two patients, three courses in one patient, and one course in one patient. One patient had grade 2 thrombocytopenia after one course, and the second course was administered at a half dose（3.7 GBq）. The overall response rate（ORR） was 25%, with one PR and two SD. The median PFS was 9 months（95% Cl, 8-NA）, and the median overall survival from diagnosis was 119 months（95%Cl, 31 - NA）. Adverse events during PRRT included leukopenia in two patients（one G3, one G2）, lymphopenia in one patient（one G3）, thrombocytopenia in two patients（two G2, one G3）, creatinine increase in one patient（one G2）, and skin rash in one patient. In conclusion, PRRT is expected to be highly effective and safe compared with conventional therapy for neuroendocrine tumors with unresectable or distant metastases

Computer-Aided Volumetry of Pulmonary Nodules Exhibiting Ground-Glass Opacity at MDCT

high-resolution CT may help in differential diagnosis. Because the doubling time of BAC is long (average, 457-813 days) With MDCT it is possible to scan a wide range, including areas containing pulmonary nodules, at a detector collimation of 0.500-0.625 mm in one breath-hold. This capability facilitates 3D evaluation of pulmonary nodules. In previous studies C a r d io p u lm o n a r y I m ag i ng • O r ig i n a l R e s e a rc h MATERIALS AND METHODS. To evaluate the accuracy of computer-aided volumetry software, we performed thin-section helical CT of a chest phantom that included simulated 3-, 5-, 8-, 10-, and 12-mm-diameter ground-glass opacity nodules with attenuation of -800, -630, and -450 HU. Three radiologists measured the volume of the nodules and calculated the relative volume measurement error, which was defined as follows: (measured nodule volume minus assumed nodule volume ÷ assumed nodule volume) × 100. Two radiologists performed two independent measurements of 59 nodules in humans. Intraobserver and interobserver agreement was evaluated with Bland-Altman methods. RESULTS. The relative volume measurement error for simulated ground-glass opacity nodules measuring 3 mm ranged from 51.1% to 85.2% and for nodules measuring 5 mm or more in diameter ranged from -4.1% to 7.1%. In the clinical study, for intraobserver agreement, the 95% limits of agreement were -14.9% and -13.7% and -16.6% to 15.7% for observers A and B. For interobserver agreement, these values were -16.3% to 23.7% for nodules 8 mm in diameter or larger. CONCLUSION. With computer-aided volumetry of ground-glass opacity nodules, the relative volume measurement error was small for nodules 5 mm in diameter or larger. Intraobserver and interobserver agreement was relatively high for nodules 8 mm in diameter or larger