Contouring of emerging organs-at-risk (OARS) of the female pelvis and interobserver variability: A study by the Italian association of radiotherapy and clinical oncology (AIRO).

Purpose: To provide straightforward instructions for daily practice in delineating emerging organs-at-risk (OARs) of the female pelvis and to discuss the interobserver variability in a two-step multicenter study. Methods and materials: A contouring atlas with anatomical boundaries for each emerging OAR was realized by radiation oncologists and radiologists who are experts in pelvic imaging, as per their knowledge and clinical practice. These contours were identified as quality benchmarks for the analysis subsequently carried out. Radiation oncologists not involved in setting the custom-built contouring atlas and interested in the treatment of gynecological cancer were invited to participate in this 2-step trial. In the first step all participants were supplied with a selected clinical case of locally advanced cervical cancer and had to identify emerging OARs (Levator ani muscle; Puborectalis muscle; Internal anal sphincter; External anal sphincter; Bladder base and trigone; Bladder neck; Iliac Bone Marrow; Lower Pelvis Bone Marrow; Lumbosacral Bone Marrow) based on their own personal knowledge of pelvic anatomy and experience. The suggested OARs and the contouring process were then presented at a subsequent webinar meeting with a contouring laboratory. Finally, in the second step, after the webinar meeting, each participant who had joined the study but was not involved in setting the benchmark received the custom-built contouring atlas with anatomical boundaries and was requested to delineate again the OARs using the tool provided. The Dice Similarity Coefficient (DSC) and the Jaccard Similarity Coefficient (JSC) were used to evaluate the spatial overlap accuracy of the different volume delineations and compared with the benchmark; the Hausdorff distance (HD) and the mean distance to agreement (MDA) to explore the distance between contours. All the results were reported as sample mean and standard deviation (SD). Results: Fifteen radiation oncologists from different Institutions joined the study. The participants had a high agreement degree for pelvic bones sub-structures delineation according to DICE (IBM: 0.9 ± 0.02; LPBM: 0.91 ± 0.01). A moderate degree according to DICE was showed for ovaries (Right: 0.61 ± 0.16, Left: 0.72 ± 0.05), vagina (0.575 ± 0.13), bladder sub-structures (0.515 ± 0.08) and EAS (0.605 ± 0.05), whereas a low degree for the other sub-structures of the anal-rectal sphincter complex (LAM: 0.345 ± 0.07, PRM: 0.41 ± 0.10, and IAS: 0.4 ± 0.07). Conclusion: This study found a moderate to low level of agreement in the delineation of the female pelvis emerging OARs, with a high degree of variability among observers. The development of delineation tools should be encouraged to improve the routine contouring of these OARs and increase the quality and consistency of radiotherapy planning.

Hippocampal sparing in stereotactic radiotherapy for brain metastases: To contour or not contour the hippocampus?

PURPOSE: The aim of our study was to evaluate hippocampal irradiation in patients treated with fractionated stereotactic brain radiotherapy. PATIENTS AND METHODS: Retrospective hippocampal dosimetric analysis performed on 22 patients with one to four brain metastases treated with fractionated stereotactic radiotherapy using volumetric intensity-modulated arc therapy. Original plans did not include hippocampus as avoidance structure in optimization criteria; hippocampus was retrospectively delineated on magnetic resonance coregistered with planning CT and using as reference the RTOG 0933 atlas. Hippocampus was defined both as a single and as pair organ. Constraints analysed were: Dmax<16Gy, D40%<7.3Gy, D100%=Dmin<9Gy. Assuming a α/ß ratio of 2Gy, biologically equivalent dose in 2Gy fractions was calculated. Hippocampal-sparing plans were developed in cases where hippocampal constraints were not respected in the original plan. RESULTS: Among constraints analysed Dmax and D40% have been exceeded in ten out of 22 cases. The constraints were not respected in patients with more than one metastatic lesion and in three patients with only one lesion. Considering all exceeded constraints values in non-hippocampal sparing plans, the 50% of them was respected after replanning. No significant differences were found among conformity and homogeneity index between non-hippocampal sparing and hippocampal sparing plans. CONCLUSION: Volumetric intensity-modulated arc therapy hippocampal sparing plans significantly decreases dose to hippocampus assuring an equal target coverage and organs at risk avoiding.

Interobserver variability of clinical target volume delineation in soft-tissue sarcomas.

PURPOSE: The present observational study reports the results of a multi-institutional dummy-run designed to estimate the consistency of interobserver variability in clinical target volume delineation in two different cases of soft-tissue sarcomas in which postoperative and preoperative radiotherapy were prescribed, respectively. The purpose of this work was to quantify interobserver variability in routine clinical practice. PATIENTS AND METHODS: Two different cases of soft-tissues sarcomas were chosen: a case of postoperative and a case of preoperative radiation therapy. Participating centres were requested to delineate clinical target volumes according to their experience in both cases. Descriptive statistic was calculated for each variable (volume, diameters) separately for two cases. Box-whiskers plots were used for presentation of clinical target volume. A Shapiro-Wilk's test was performed to evaluate the departures from normality distribution for each variable. The comparison between relative variations of diameters was evaluated using the Student's t test. RESULTS: Several variations affecting both volumes and diameters were observed. Main variations were observed in the craniocaudal and laterolateral diameters. Each case showed similar dispersion, indicating a lack of reproducibility in volumes definition. CONCLUSIONS: This observational study highlighted that, in the absence of specific instructions or guidelines, the interobserver variability can be significant both in postoperative and preoperative radiotherapy of soft-tissue sarcomas.

Diffusion-weighted magnetic resonance for prediction of response after neoadjuvant chemoradiation therapy for locally advanced rectal cancer: preliminary results of a monoinstitutional prospective study.

PURPOSE: To evaluate diffusion-weighted imaging (DWI) for assessment of treatment response in locally advanced rectal cancer (LARC) 8 weeks after neoadjuvant chemoradiotherapy (CRT). METHODS AND MATERIALS: A total of 28 patients with LARC underwent magnetic resonance imaging (MRI) prior to and 8 weeks after CRT. Tumor volume (TV) was calculated on T2-weighted MRI scans as well as the apparent diffusion coefficient (ADC) was calculated using Echo-planar DWI-sequences. All data were correlated to surgical results and histopathologic tumor regression grade (TRG), according to Mandard's classification. Post-treatment difference ADC (%ΔADC) and TV (%ΔTV) changes at 8 weeks were compared complete response (CR; TRG1) and non-complete response tumors (non-CR; TRG2-5). RESULTS: The mean % ADC increase of CR group was significantly higher compared to non-CR group (77.2 ± 54.63% vs. 36.0 ± 29.44%; p = 0.05). Conversely, the mean % TV reduction did not significantly differ in CR group from non-CR group (73.7% vs. 63.77%; p = 0.21). Accordingly, the diagnostic accuracy of the mean % ADC increase to discriminate CR from non-CR group was significantly higher than that of the mean % TV reduction (0.913 vs. 0.658; p = 0.022). No correlation was found between mean % TV reduction and TRG (rho = 0.22; p = 0.3037), whereas a negative correlation between mean % ADC increase and TRG was recorded (r = -0.69; p = 0.006). CONCLUSION: The mean % ADC increase appears to be a reliable tool to differentiate CR from non-CR after CRT in patients with LARC.

Surgical management of lip cancer.

Lip cancer is the most frequent malignant neoplasm of the oral cavity. The study reported herewith refers to the clinico-pathological features and surgical treatment of lip cancer. The most frequent tumour related to the lips is squamous cell carcinoma, with the lower lip more commonly involved than the upper lip. Typically, squamous cell carcinoma originates in the red lip, whereas basal cell carcinoma involves the white lip. The management of lip cancer involves the control not only of the primary tumours with oncologically appropriate margins and subsequent reconstruction to allow oral competence during the oral phase of swallowing, but also the possible metastatic spread to the neck. Reconstruction is a surgical challenge especially for advanced and extended lesions. A successful reconstruction depends on careful pre-operative planning, knowledge of the anatomy and use of the various surgical techniques. Lymph node neck metastases significantly reduce long-term survival. Although the management of the neck is controversial in lip cancer, particularly with respect to the neck, elective or curative supra-omohyoid neck dissection is the best choice for occult or evident loco-regional metastases. Early stage tumours have good prognostic, aesthetic and functional results after surgery compared to the treatment of advanced lesions, which alter the appearance and functionality of the lip. The Authors report their experience in the treatment of lip tumours at the primary site, considering reconstructive problems, together with management of neck metastases.

Parotid surgery in patients over seventy-five years old.

Malignant parotid tumours are generally rare but become more common in the last decades of life; this increased incidence concerns mainly secondary parotid space involvement from metastasis or direct invasion. During the past five years, we observed and operated upon 84 patients for parotid diseases, performing 86 parotidectomies (2 bilateral operations). The patients included 30 (35.7%) over 75 years old (2 subjects over 90), mean age 80.5 years, object of the present study. In these 30 patients 2 chronic infections were observed, 6 benign tumours and 22 malignant tumours with only 6 primary neoplastic lesions. Overall, 14 extended radical parotidectomies were performed, 13 conservative total parotidectomies, 2 superficial parotidectomies and 1 radical parotidectomy, a few associated with neck dissection and/or radiotherapy. Three patients died in the post-operative period from heart attack. Five patients died from disease (3 from melanomas--2 after 3 years and 1 after 2 years--and 2 from primary carcinomas--1 after 2 years and 1 after 1 year). Six patients died without disease from various causes (2 after 4 years, the others after 3, 2, 1 year and 8 months). Nine patients are alive, 8 NED and 1 with disease in the ethmoid after 2 years, the latter well under control with radiotherapy. This experience implies that surgical treatment of these secondary tumours, which are performed more frequently in old age, exposes the patient to the risk of serious complications (3 patients died in the immediate post-operative period) and stresses the importance of careful evaluation of general conditions. However, surgery seems to have been the treatment indicated also in the patients who subsequently died from the disease, but in whom at least two-year survival was achieved in almost all cases. Unfortunately, because of the advanced age of the patients, the final results are penalized by deaths from natural causes. It is, nevertheless, encouraging that over one third of the patients operated upon are free of disease.

Canalplasty for severe external auditory meatus exostoses.

Exostoses of the external auditory meatus is a well known condition which infrequently requires surgical correction. However, the stenosis caused by severe exostosis can affect quality of life considerably and may require surgical intervention. Canalplasty, in such a situation, is a valid and effective management option. In our series the commonest indication for surgery was recurrent otitis externa. The detailed surgical technique is described and a retrospective analysis of 65 such procedures is presented. There were only two significant complications, both post-operative stenosis, requiring further corrective surgery. In conclusion, canalplasty for the exostosis of the external auditory meatus is a safe surgical option.