Dosimetric evaluation of irregular surface compensator and intensity-modulated radiotherapy in breast radiotherapy.

BACKGROUND: This dosimetric study aims to evaluate the dosimetric advantage of the irregular surface compensator (ISC) compared with the intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Ten patients with whole breast irradiation were planned with the ISC and IMRT techniques. Six different beam directions were selected for IMRT and ISC plans. The treatment plans were evaluated with respect to planning target coverage, dose homogeneity index (DHI) and organs at risk (OARs) sparing. Monitor units (MUs) and the delivery time were analysed for treatment efficiency. RESULTS: The ISC technique provides a better coverage of the PTV and statistically significantly better homogeneity of the dose distribution. For the ipsilateral lung and heart, ISC and IMRT techniques deliver almost the same dose in all plans. However, MU counts and delivery time were significantly lower with the IMRT technique (p < 0.05). CONCLUSION: For breast radiotherapy, when the ISC method was compared to the IMRT method, ISC provided better dose distribution for the target.

Prognostic factors in clinical stage T4N2 locally advanced non-small cell lung cancer.

PURPOSE: Relatively few studies have focused on T4N2 (stage IIIB) locally advanced non-small cell lung cancer (NSCLC). In this study, we tried to identify prognostic factors for patients with clinical stage T4N2 NSCLC. METHODS: We retrospectively identified 223 patients, of which 168 met the inclusion criteria. Patients treated with curative intent using concurrent chemoradiotherapy (CRT) with or without adjuvant chemotherapy, or concurrent CRT after induction chemotherapy, were included in this study. Relevant patient, treatment, and disease factors were evaluated for their prognostic significance in both univariate and multivariate analyses using the Cox proportional hazards model. RESULTS: The median progression-free survival (PFS) was 13 months (95% confidence interval [CI], 10.6-15.4). The median overall survival (OS) was 20 months (95% CI, 16.8-23.1), and 71, 40.3 and 28.2% of the patients survived for 1, 2 and 3 years after diagnosis, respectively. Multivariate analysis showed Eastern Cooperative Oncology Group (ECOG) performance status (PS) was independent predictor of PFS (hazard ratio [HR], 0.24; 95% CI, 0.13-0.43; p=0.001), and OS [HR, 0.48; 95% CI, 0.26-0.87; p=0.015). Absence of multifocal T4 tumors was also associated with a significantly longer OS (HR, 046; 95% CI, 0.31-0.7; p=0.001). There was no statistically significant difference in OS and PFS between treatment modalities. CONCLUSION: PFS and OS were significantly shorter in patients with poor ECOG PS. OS was also significantly shorter in patients with multifocal T4 tumors. There were no differences between the two therapeutic approaches with respect to outcome.

Results of radiotherapy in squamous cell laryngeal cancer: A tomotherapy center experience.

Background: Laryngeal cancer is a common type of head and neck cancer (HNC). Radiotherapy (RT) is a mainstay for curative treatment. Intensity-modulated RT (IMRT) is a standard technique today, as it provides of higher survival and local control and lower normal tissue toxicity. One of IMRT devices is helical tomotherapy (HT). The HT treatment results of HNC patients have been reported in few studies. We aimed to investigate the results of squamous cell laryngeal carcinoma patients treated with helical tomotherapy. Methods: Forty-five laryngeal cancer patients were selected according to the inclusion criteria. Radiotherapy (RT) plans were set in the Hi-Art HT planning system. Image-gated RT (IGRT) technique was used. Appropriate patients received simultaneous cisplatin. Treatment response rates were evaluated at the post-RT third and sixth months. Survival times were calculated with the Kaplan-Meier method. The factors affecting the treatment results were evaluated using Log-rank and Cox regression tests. A P value of less than 0.05 was accepted as statistically significant. Results: The median age was 65 (28-84) years. The median symptom duration was 6 (1-60) months. The RT dose for the early and the locally advanced disease was median 63 Gy (60.75-66) and 66 Gy (60-70), respectively. The RT interruption was median two (0-20) days. The patients were followed up to 25 (1-45) months. Grade 2 xerostomia and dysphagia rates were 55% and 7%, respectively. The 3-year estimates of overall survival (OS), disease-free survival (DFS), metastasis-free survival (DMFS), and locoregional recurrence-free survival (RRFS) were 71.7%, 60.4%, 84.9%, and 68.5%, respectively. In univariate analysis, the presence of N2 disease was a negative prognostic for DFS (P = 0.05) and DMFS (P = 0.003). RT interruption >2 days was a negative prognostic for OS (P = 0.005), DFS (P = 0.02), and RRFS (P = 0.023). In the multivariate analysis, symptom duration >6 months was found to be the only significant factor for DFS (P < 0.05). Conclusion: Intensity-modulated radiation with HT achieved comparable clinical outcomes with acceptable toxicity in laryngeal carcinoma.

Evaluation of incidental testicular dose with thermoluminescence dosimetry during prostate radiotherapy.

The aim of this study was to investigate incidental testicular doses during intensity modulated radiation therapy (IMRT) in patients treated with prostate radiotherapy only (PORT) and whole pelvis radiotherapy (WPRT). A total of 34 prostate cancer patients with intermediate and high risk were included in this prospective study. Each patient in the intermediate risk group received a total of 78 Gy in 39 fractions for prostate and seminal vesicles. In patients in the high risk group, 2 Gy daily fraction dose for pelvic lymphatics was given to 50 Gy, and then 78 Gy was given to prostate and seminal vesicles volumes. Treatment plans were created for all patients using the IMRT technique with 6MV. Testicular doses were measured for WPRT and PORT by thermoluminescence dosimetry (TLD) detectors placed on testis surface. Testicular doses measured for WPRT and PORT were compared. The isocenter to testicular distance for WPRT and PORT was 16.83-cm (13.20 to 18.80-cm) and 11.15 cm (9.10 to 13.00-cm), respectively. The mean testicular dose measurements of TPS and TLD per fraction during PORT were 2.41 cGy (1.95 to 3.60 cGy) and 3.70 cGy (2.80 to 5.10 cGy), respectively (p = 0.00). In WPRT irradiation, mean testicular dose values of TPS and TLD per fraction were measured as 3.85 cGy (2.00 to 5.70 cGy) and 5.85 cGy (4.25 to 7.55 cGy), respectively (p = 0.00). The cumulative mean scattered dose for PORT irradiation of 78 Gy in 39 fractions was 144.30 cGy. The mean cumulative dose received by the testis for the high-risk prostate patient was 228.15 cGy. There was a significant difference in testicular dose between WPRT and PORT irradiation. Testicular doses decreased significantly with increasing isocenter-testis distance. Incidental testicular dose during prostate radiotherapy can be significantly detrimental to spermatogenesis. Therefore, the testicles should be contoured as an organ at risk for the estimation of absorbed doses. The use of in vivo dosimetry is recommended for accurate measurement of testicular dose in radiotherapy of prostate cancer for men desiring continued fertility.

Impact of different treatment plans on EQD2 for intracavitary brachytherapy of cervical cancer.

BACKGROUND: Cancer is one of the leading causes of death worldwide. According to GLOBOCAN estimates, there were 341,831 deaths from cervical cancer in 185 countries in 2020. The aim of this study was to compare equieffective dose (EQD2) at 2 Gy per fraction by using dose volume histograms (DVHs) derived from external beam radiotherapy (EBRT) and high-dose rate brachytherapy (HDR-BRT) treatment plans used in cervical cancer radiotherapy. METHODS: Fifteen patients with stage IIB-IIIB cervical cancer were included in this retrospective study. Treatment with three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) was planned for all patients in 28 fractions, with a total of 50.4 Gy to be delivered to the whole pelvic region. After EBRT, manual optimization (MO) or inverse optimization (IO) HDR-BRT plans were created in 4 fractions with a total of 28 Gy. The plans obtained were grouped as IMRT + IO, IMRT + MO, 3DCRT + IO, and 3DCRT + MO by calculating EQD2s among these plans. D90, D95, and D98 values were compared in all plans for CTVHR total EQD2. In addition, EQD2 values ​for critical organs at risk (OARs) such as rectum, bladder, small intestine, and sigmoid were compared in all plans for volumes of 2 cm3, 1 cm3, and 0.1 cm3, respectively. RESULTS: There was no significant difference between the treatment groups in terms of CTVHR D90 and CTVIR D90 values; However, CTVHR D95 (p = 0.000) and CTVHR D98 (p = 0.000) values ​were found to be better in IMRT + IO technique. The IMRT + IO technique provided better protection for 2 cm3, 1 cm3, and 0.1 cm3 volumes of OARs compared to other techniques. CONCLUSIONS: Considering all parameters such as CTVHR, CTVIR, rectum, bladder, small intestine, and sigmoid, combination of IMRT + IO treatment option was found to be significantly superior in total EQD2 calculations compared to other plans.

Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: Outcomes of survival, toxicity, sphincter preserving and prognostic factors.

BACKGROUND: This study aimed to compare preoperative chemoradiotherapy (CRT) with postoperative CRT regarding survival, local control, disease control, sphincter preservation, toxicity and also prognostic factors for the treatment of locally advanced rectal cancer. METHODS: Records of 140 patients with locally advanced rectal cancer who received preoperative or postoperative CRT were analyzed retrospectively. We compared the treatment groups (preoperative vs postoperative) according to baseline characteristics (demographic and rectal cancer disease characteristics), and also carried out the survival analyses. RESULTS: From January 2010 to December 2019, 140 patients were included in the analysis, 65 received preoperative treatment and 75 postoperative treatment. There was no difference in survival, recurrence or distant metastasis rate in both treatment groups. The ratios of the failure to complete adjuvant chemotherapy (32% vs 4.6%) and acute grade 3-4 toxicity (32% vs 6.2%) were higher in the postoperative group (p < 0.001). In lower located tumors (≤5 cm from anal verge) the ratio of the sphincter preserving in the preoperative group was 60.7% (n = 17/28), and was 16.6% (n = 3/18) in the postoperative group (Yates χ2 = 5.829, p = 0.005). CONCLUSION: This study showed no difference in recurrence and survival rate. Preoperative CRT is the preferred treatment for patients with locally advanced rectal cancer, given that it is associated with a superior overall treatment compliance rate, reduced toxicity, and an increased rate of sphincter preservation in low-lying tumors, but not for overall survival.

Treatment outcomes and survival study of gastric cancer patients: a retrospective analysis in an endemic region.

PURPOSE: To present information about prognostic factors of gastric cancer patients treated in our Erzurum center including age, gender, tumour location, pathological grade, stage and the effect of treatment on survival. MATERIALS AND METHODS: This retrospective study was performed on patients who applied to our clinic and diagnosed as gastric cancer. Age and gender of the patients, primary location, histopathological characteristics, TNM stage of the gastric cancers (GCs), treatment applied, oncological treatment modalities and survival outcomes were studied. A univariate analysis of potential prognostic factors was performed with the log-rank test for categorical factors and parameters with a p value < 0.05 at the univariate step were included in the multivariate regression. RESULTS: A total of 228 patients with a confirmed diagnosis of gastric cancer were included in the study with a male/female ratio of 1.47. Median follow-up period was estimated as 22.3 (range, 3 to 96) months. When diagnosis of the patients at admission was analysed, stage III patients were most frequently encountered (n=147; 64.5%). One hundred and twenty-six (55.3%) underwent surgical treatment, while 117 (51.3%) were given adjuvant chemotherapy. Median overall survival time was 18.0 (± 1.19) months. Mean overall survival rates for 1, 2, 3 and 5 years were 68 ± 0.031%, 36 ± 0.033%, 24 ± 0.031% and 15.5 ± 0.036%, respectively. Univariate variables found to be significant for median OS in the multivariate analysis were evaluated with Cox regression analysis. A significant difference was found among TNM stage groups, location of the tumour and postoperative adjuvant treatment receivers (p values were 0.011, 0.025 and 0.001, respectively). CONCLUSIONS: This study revealed that it is possible to achieve long-term survival of gastric cancer with early diagnosis. Besides, in locally advanced GC patients, curative resection followed by adjuvant concomitant chemoradiotherapy based on the McDonald regimen was an independent prognostic factor for survival.

Dietary and demographical risk factors for oesophageal squamous cell carcinoma in the Eastern Anatolian region of Turkey where upper gastrointestinal cancers are endemic.

BACKGROUND: Oesophageal squamous cell carcinoma (ESCC) is endemic in the Eastern Anatolian region of Turkey. The present study was performed to identify risk factors for ESCC that specifically reflect the demography and nutritional habits of individuals living in this region. MATERIALS AND METHODS: The following parameters were compared in 208 ESCC patients and 200 control individuals in the Eastern Anatolian region: age, sex, place of living, socioeconomic level, education level, smoking, alcohol intake, nutritional habits, and food preservation methods. RESULTS: The mean age of ESCC patients was 56.2 years, and 87 (41.8%) were 65 years-old or older. The ratio of women to men in the patient group was 1.39/1. ESCC patients consumed significantly less fruit and yellow or green vegetables and more hot black tea, 'boiled yellow butter', and mouldy cheese than did control individuals. Residence in rural areas, smoking, and cooking food by burning animal manure were also significantly associated with ESCC. CONCLUSIONS: The consumption of boiled yellow butter and mouldy cheese, which are specific to the Eastern Anatolian region, and the use of animal manure for food preparation were identified as risk factors in this region. Further studies are required to potentially identify the carcinogenic substances that promote the development of ESCC in this region.

Impact of poster presentations on academic knowledge transfer from the oncologist perspective in Turkey.

BACKGROUND: Currently poster presentations offer a common visual medium for knowledge transfer by a wide range of health professionals. Our study aimed to determine the scientific importance of poster presentations for Medical and Radiation Oncologists. METHODS: A survey form including 40 questions was distributed to a total of 131 oncologists experienced in poster presentations. One hundred completed survey forms were included in the study. Descriptive statistics and modified thematic analyses were performed on the responses. RESULTS: Overall 64% of the participants agreed that posters were a good medium for knowledge transfer. Some 88% agreed that concise and clear styled presentations would increase appealing interests for poster contents. Visual appearance was cited more influential than content of the subject; 70% of participants agreed that appearances of posters could help to draw more viewer attention. Of respondents, 63% believed that posters accompanied by their author were more attractive for congress attendees, and 33% of them declared that the halo effect of the poster presenter was also important. CONCLUSION: The present study indicated that intelligibility, appearance and visuality of posters are most important factors from the aspect of oncologist participants. Presenters must take into account these important points when preparing their academic posters.

Painful plantar heel spur treatment with Co-60 teletherapy: factors influencing treatment outcome.

BACKGROUND: Painful plantar heel spur (PPHS) is a benign disorder with painful heels as a result of plantar calcaneal bone spur. Exact etiological factors are still unclear. Treatment typically consists of osteoarthritis tretment schedules and surgical techniques. External radiotherapy is another treatment option. This study is aimed to determine effectiveness and treatment outcomes of external radiotherapy in patients with PPHS. METHODS: Sixty-two patients with PPHS were analysed for radiotherapy success and other possible prognostic factors. All patients were treated with Co-60 units from parallel opposed lateral portals, to a total dose of 8 Gy. Responses to radiotherapy was assessed by visual analogue scale (VAS) of pain. Follow-up completed in December 2012 with 28 months median duration (range 22 to 35 months). Age, sex, patient number, spur settlement site, prior treatments, time interval between diagnosis and radiotherapy, pain scores (before and after radiotherapy), plantar fat-pillow thickness (PFPT; thickness of the plantar fat pad) and Böhler's angle estimations were analysed. RESULTS: Study included 53 female and 9 male patients with median age 57 (range 43-70). Time interval between PPHS diagnosis and radiotherapy were median 33 months (range10-60). Radiotherapy response time interval were 6 months (range 3-10 months). Responses to radiotherapy were no response in 13 patients (21%), partial response in 13 patients (21%)- pain relief below 50% and complete response - no pain in 36 patients (58%) respectively. Median PFPT of patients were 3.5 cm (range 1.20-4.50 cm). Complete response rate was statistically significant in patients whom PFPT is greater than 3.5 cm. The Böhler's angle range is about 20-40 deg. Complete response rates were higher in patients with degree of Böhler's Angle 30 and below. CONCLUSIONS: Simplicity of treatment, lack of acute adverse effects and low cost, seem to make radiotherapy one of the safest, cheapest and also an effective treatment modality for PPHS.

Comparison of linear accelerator and helical tomotherapy plans for glioblastoma multiforme patients.

BACKGROUND: Despite advances in radiotherapy, overall survival of glioblastoma multiforme (GBM) patients is still poor. Moreover dosimetrical analyses with these newer treatment methods are insufficient. The current study is aimed to compare intensity modulated radiation therapy (IMRT) linear accelerator (linac) and helical tomotherapy (HT) treatment plans for patients with prognostic aggressive brain tumors. MATERIAL AND METHODS: A total of 20 GBM patient plans were prospectively evaluated in both linac and HT planning systems. Plans are compared with respect to homogenity index, conformity index and organs at risk (OAR) sparing effects of the treatments. RESULTS: Both treatment plans provided good results that can be applied to GBM patients but it was concluded that if the critical organs with relatively lower dose constraints are closer to the target region, HT for radiotherapeutical application could be preferred. CONCLUSION: Tomotherapy plans were superior to linear accelerator plans from the aspect of OAR sparing with slightly broader low dose ranges over the healthy tissues. In case a clinic has both of these IMRT systems, employment of HT is recommended based on the observed results and future re-irradiation strategies must be considered.

Prominent response with helical tomotherapy in recurrent ameloblastic carcinoma of maxillary sinus: a case report.

INTRODUCTION: Ameloblastoma is a benign but locally aggressive tumor of odontogenic epithelial tissue. Reports of radiotherapy treatment modalities are limited in the literature. CASE PRESENTATION: A thirty-five year old male presented with complaints of headache radiating to his face for about six months and impaired vision. The patient's Positron Emission Tomography (PET) showed a mass in the left maxillary sinus extending to the nasal cavity and invading the adjacent tissues. An R2 (macroscopic residual tumor) surgical resection performed to debulk the tumor. Due to the recurrence and residual mass, the patient was treated with helical tomotherapy. At 2 months post-radiotherapy, patient's vision returned to normal. PET scan showed a significant reduction in lesion size 12 months post-radiation. CONCLUSION: In cases of ameloblastic carcinoma with, post-surgical recurrence or patients not suitable for surgical treatment, helical tomotherapy can be an effective treatment option.