Value of Conventional MRI, DCE-MRI, and DWI-MRI in the Discrimination of Metastatic from Non-Metastatic Lymph Nodes in Rectal Cancer: A Systematic Review and Meta-Analysis Study.

BACKGROUND: Today, despite many studies on the diagnosis of metastasis to lymph nodes (LNs) in Rectal Cancer (RC), its diagnosis is still very challenging for radiologists. The purpose of the present study was to the assessment of the diagnostic value of conventional MRI, DCE-MRI, and DWI-MRI in the discrimination of metastatic from non-metastatic lymph nodes in RC. METHODS: In the present meta-analysis study, we surveyed international databases including PubMed, Scopus, Embase, and Science Direct with appropriate keywords. Using the binomial distribution formula, the variance of each study was calculated and the data were analyzed using STATA version 14. Finally, the results of the studies were entered into the random-effects meta-analysis.  Also, we used the chi-squared test and I2 index to calculate heterogeneity among studies, and for evaluating publication bias, Funnel plots and Egger tests were used. RESULTS: 31 articles published between 2005 and 2021, comprising 2517 patients were included in the present study. The sensitivity and specificity of DCE-MRI were 83% (74% to 80%), and 86% (80% to 93%), respectively with PPV 84% (76% to 89%) and NPV 88% (79% to 95%). Also, the sensitivity and specificity of DWI-MRI were 81% (74% to 88%), and 74% (78% to 91%), respectively with PPV 63% (54% to 74%), NPV 85% (77% to 93%), AUC 80 % (75% to 86%) and accuracy 82% (75% to 88%). For conventional MRI, the sensitivity 74% (67% to 80%), specificity 77% (71% to 83%), PPV 62% (48% to 69%), NPV 70% (62% to 77%), AUC 78% (72% to 83%) and 71% accuracy (68% to 78%) was obtained. CONCLUSION: Based on our finding DCE-MRI is the most suitable technique for the discrimination of metastatic lymph nodes in rectal cancer.

Evaluation of Dose Distribution in Optimized Stanford Total Skin Electron Therapy (TSET) Technique in Rando Anthropomorphic Phantom using EBT3 Gafchromatic Films.

BACKGROUND: The Total Skin Electron Therapy (TSET) targets the whole of skin using 6 to 10 MeV electrons in large field size and large Source to Surface Distance (SSD). Treatment in sleeping position leads to a better distribution of dose and patient comfort. OBJECTIVE: This study aims to investigate the uniformity of absorbed dose in the sleeping Stanford technique on the Rando phantom using dosimetry. MATERIAL AND METHODS: It is an experimental study which was performed using 6 MeV electron irradiation produced by Varian accelerator in the AP and PA positions with gantry angles of 318/3, 0 and 41/5 degrees, and RAO, LAO, RPO and LPO with 291/4 gantry angle and 45 degrees of collimator angle in the sleeping position. RESULTS: The results show that the dose uniformity achieved in this technique is in the range of (100 ± 25%) and, the dose accuracy was 6%. CONCLUSION: Total Skin Electron Therapy (TSET) technique in sleeping position is very suitable for elderly and disabled patients, and meets the required dose uniformity. Furthermore, the use of a flattening filter is recommended for the more dose distribution uniformity.

Outcomes of Surgical Excision and Brachytherapy in Intractable Keloids.

BACKGROUND: Keloids as unusual scars are injury remnants characterized by bizarre cosmetics and painful itching. This study assessed outcomes of surgical excision and brachytherapy in intractable keloids. METHODS: Six patients with 10 keloid lesions were followed up. Surgical excision was done with 1-2 mm margin, and then radiotherapy was undertaken in 3 divided fractions on days 0, 1 and 2 after surgery. Scar improvement was evaluated by patients and observer with scar assessment scale (POSAS). RESULTS: Median age of patients was 38.3±6.4, while 40% were male and 60% were female. The mean primary size of the lesion before brachytherapy was 325.18±426.16 mm2 and the median size was 153.48 mm2. The mean primary size of the lesions with recurrence before brachytherapy was 150.50±124.78 mm2. The clinical improvement of the scars with POSAS scoring by the observer was 17.1±3.2 and by the patients was 20.8±11.5. In 5 patients who were evaluated, two keloid lesions showed recurrence (20%), and 8 lesions had no recurrence (80%). No patients reported side effects, but only one patient, a 43 years old woman with 5 keloid lesions, suffered wound infection and local dehiscence of the wound, followed by the second session of brachytherapy. The average time of relapse was 26.3±0.9 months. CONCLUSION: The use of surgical resection in combination with brachytherapy was demonstrated as a modality for treatment of refractory keloid scars that can be recommended to surgeons who deal with these patients.

In vivo dosimetry with semiconductors in medium dose rate (MDR) brachytherapy for cervical cancer.

PURPOSE: This study was performed to evaluate the role of in vivo dosimetry with semiconductor detectors in gynaecological medium dose rate brachytherapy, and to compare the actual doses delivered to organs at risk (as measured using in vivo dosimetry) with those calculated during treatment planning. MATERIALS AND METHODS: Doses to the rectum and bladder were measured in a group of patients with cervical carcinoma using semiconductor detectors and compared to the doses calculated using a treatment planning system. 36 applications of brachytherapy at dose rates of 1.8-2.3 Gy/h were performed in the patients. RESULTS: The mean differences between the measured and calculated doses were 3 % for the rectum and 11 % for the bladder. CONCLUSIONS: The main reason for the differences between the measured and calculated doses was patient movement. To reduce the risk of large errors in the dose delivered, in vivo dosimetry should be performed in addition to treatment planning system computations.

Chemoradiation in nasopharyngeal carcinoma: a 6-year experience in Tehran cancer institute.

To determine the addition of value of neoadjuvant, concurrent and adjuvant chemotherapy to radiation in the treatment of nasopharyngeal carcinoma with regard to the overall survival (OS) and disease free survival (DFS) within a six year period in Tehran cancer institute. Files of all patients with nasopharyngeal carcinoma treated by radiotherapy with or without concurrent chemotherapy in a curative setting in Tehran cancer institute during the period of 1999-2005 were retrospectively reviewed.. A total of 103 patients with nasopharyngeal carcinoma had been treated during the study period with radiotherapy or chemoradiotherapy in our institute. There were 29 (28.2%) females and 74 (71.8%) males. The median age at the time of radiotherapy was 47 years old (range 9-75 years). The patients were followed 2 to 76 months with a median follow-up of 14 months. Time of first recurrence after treatment was 3-44 months with a median of 10 months.. Survival in 2 groups of patients treated with radiotherapy alone or chemoradiation did not have a significant difference (P>0.1). Two-year survival in patients treated with or without adjuvant chemotherapy and had local recurrence after treatment did not have significant difference (P>0.1). Two-year survival in patients with or without local recurrence after treatment did not have significant difference (P>0.1). A beneficial affect or a survival benefit of adjuvant/neoadjuvant chemotherapy and concurrent chemoradiation was not observed in Iranian patients.

Phase III randomized trial of very accelerated radiation therapy compared with conventional radiation therapy in squamous cell head and neck cancer: a GORTEC trial.

PURPOSE: With the aim to increase the dose intensity of radiation therapy (RT), and subsequently the locoregional control rate, a very accelerated RT regimen was compared with conventional RT in a series of patients with head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Between 1994 and 1998, 268 patients with T3 or T4, N0 to N3 HNSCC (staged by 1997 International Union Against Cancer criteria) that was not eligible for surgery were randomly assigned to receive either conventional RT, delivering 70 Gy in 7 weeks to the primary tumor and 35 fractions of 2 Gy over 49 days, or to receive very accelerated RT, delivering 62 to 64 Gy in 31 to 32 fractions of 2 Gy over 22 to 23 days (2 Gy/fraction bid). RESULTS: The most common tumor site was the oropharynx and most of the patients (70%) had T4 and N1 to N3 tumors in 72% of patients. The main patient and tumor characteristics were well-balanced between the two arms. The median total doses were 63 Gy (accelerated) and 70 Gy (conventional), with a median overall time of 22 days and 48 days, respectively. Acute mucositis was markedly increased in the accelerated-RT arm (P < .001). The locoregional control rate was improved by 24% at 6 years with accelerated RT. In contrast, disease-free survival and overall survival were not significantly different between the two arms. There was no difference in late effects between the two arms. CONCLUSION: The very accelerated RT regimen was feasible and provided a major benefit in locoregional control but had a modest effect on survival.