Conformal Intensity-modulated Radiotherapy Research Articles

Impact du curage ganglionnaire cervical dans la prise en charge par chimioradiothérapie exclusive des cancers de l’oropharynx de stade N2-3 : étude observationnelle en vie réelle

PurposeThe purpose of this study was to assess the efficacy in terms of neck failure of an initial neck dissection before definitive chemoradiotherapy in N2-3 oropharyngeal squamous cell carcinomas, as well as the dosimetric impact and the acute and delayed morbidity of this approach. Materials and methodsAll patients consecutively treated between 2009 and 2018 with definitive chemoradiotherapy using intensity-modulated conformal radiotherapy (IMRT) for a histologically proven N2-3 oropharyngeal squamous cell carcinomas were retrospectively included. The therapeutic approach consisted of induction chemotherapy, followed by cisplatine-based chemoradiotherapy preceded or not by neck dissection. Neck dissection was discussed on a case-by-case basis in a dedicated multidisciplinary tumour board for patients with a dissociated response to induction chemotherapy, defined as a better response on the primary than on the node. Chemoradiotherapy without neck dissection was systematically performed in case of a major lymph node response to induction chemotherapy (decrease in size of 90% or more). Intensity-modulated radiotherapy using a simultaneous-integrated boost delivered 70Gy in 35 fractions on macroscopic tumour volumes, 63Gy on intermediate-risk levels or extra-nodal extension and 54Gy on prophylactic lymph node areas. ResultsTwo groups were constituted: 47 patients without an initial neck dissection (62.7%), and 28 patients with a neck dissection prior to definitive chemoradiotherapy (37.3%). Initial patient characteristics were not statistically different between the two groups. The median follow-up was 60.1months (range: 3.2–119months). Incidence of neck failure was higher in patients without neck dissection (P=0.015). The neck failure rate at 5years was 19.8% (95% confidence interval: 7.4–30.6%; P=0.015) without neck dissection versus 0% following neck dissection. All lymph node failures occurred in the planned target volume at 70Gy. Upfront neck dissection suggested a decrease in the mean dose received by the homolateral parotid gland (P=0.01), mandible (P=0.02), and thyroid gland (P=0.02). Acute toxicity of chemoradiotherapy after neck dissection suggested a reduction in grade≥3 adverse events (P=0.04), early discontinuation of concomitant chemotherapy (P=0.009) and feeding tube-dependence (P=0.008) in univariate analysis. During follow-up, there was no difference between the two groups in terms of xerostomia, dysgeusia, dysphagia or gastrostomy dependence in univariate analysis. ConclusionNeck dissection prior to definitive chemoradiotherapy in N2-3 oropharyngeal squamous cell carcinoma was associated with high neck control without additional mid and long-term morbidity.

Prospective evaluation of intensity-modulated radiotherapy toxicity in extremity soft tissue sarcomas patients: A role for irradiated healthy soft tissue volume?

AimTo prospectively assess toxicities of curative-intent intensity-modulated conformal radiotherapy (IMRT) in patients with extremity soft tissue sarcomas (ESTS). MethodsData from 59 consecutive patients with ESTS between 2014 and 2019 were both retrospectively and prospectively analysed. Toxicity data were collected both by confidential mailed survey (39% completed) and medical charts, and graded according to CTCAE v5.0. Normal tissues dosimetric data (healthy soft tissue segment, joint and bone) were included. The healthy soft tissue segment was created by adding 5 cm on either side of the PTV on CT axial slices, the PTV and bone (and articulation if present) were then removed from the generated volume. ResultsIMRT was delivered post-operatively for nearly half of patients (n = 24, 41%), preoperatively for 18 (31%) and exclusively for 17 (28%; salvage: 13% or immediately inoperable: 15%). The median total dose delivered to the planned target volume (PTV) was 50.4 Gy (36–68 Gy) and 13 patients (22%) received a boost. With a median follow-up of 27 months (6–94 months), a total of 87 late effects were identified in 44/59 (75%) patients: 89% G1–2, and 11% G3–4. The main G1-2 toxicities were: functional limitation (36%), oedema (29%), gait disorders (20%), neurological disorders (20%) and chronic pain (32%). G3-4 toxicities were pain (n = 2), arterial stricture (n = 1) and a chronic wound requiring skin graft (n = 2). No bone fracture was observed. Quality of life was rated as good or very good in 70% patients who completed the survey. Larger (>3500 cm3) healthy soft tissue segment volume was associated with decreased late toxicities (p = 0.02). No other predictive factor of toxicity was identified. The 2-year rates of local control, overall survival and recurrence-free survival were 90%, 90% and 64%, respectively. ConclusionHealthy soft tissue segment volume influenced toxicity. Long-term prospective monitoring in a homogeneous population remains critical to assess the impact of IMRT induced chronic toxicity in ESTS patients. This should ideally lead to a validated normal tissue dose constraint (e.g.: healthy soft tissue segment volume > 3500 cm3) to recommend for practitioners to help reduce the late toxicity risk.

Outcome and safety analysis of endometrial cancer patients treated with postoperative 3D-conformal radiotherapy or intensity modulated radiotherapy

Background We sought to analyze the toxicity rates and the treatment outcomes in endometrial cancer (EC) patients treated with postoperative three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT). Material and methods The clinical data of 646 EC patients treated with postoperative adjuvant 3DCRT (265 patients, 41%) or with IMRT (381 patients, 59%) between April 2007 and August 2019 were retrospectively analyzed. The primary endpoints were treatment-related acute and late gastrointestinal (GI) and genitourinary (GU) toxicities. The secondary endpoints were LC and overall survival (OS) and disease-free survival (DFS). Results Median follow-up time was 37 months. The rates for acute GI and GU toxicities of any grade for the entire group were 55.6% and 46.8%, respectively. Acute grade ≥2 GI toxicity was significantly less in patients treated with IMRT compared to those treated with 3DCRT (11.0% vs. 19.2%, p=.004). However, no significant difference grade ≥2 GU toxicities was observed between the 3DCRT and IMRT groups (15.1% vs. 11.0%; p=.15). Acute grade ≥2 GI and GU toxicities were higher in patients receiving systemic chemotherapy, while paraaortic field irradiation increases only the risk of acute grade ≥2 GI toxicity. Estimated 3-year late grade ≥3 GI toxicity rates in the 3DCRT- and IMRT-treated patients were 4.6% and 1.9% (p= .03), respectively. The patients treated with adjuvant ChT had higher rates of late serious GI complications than those without adjuvant ChT. No significant difference in terms of survival and disease control was observed between the 3DCRT and IMRT treatment groups. No significant factor for LC was found in the multivariate analysis. Conclusion In this multicentric study involving one of largest patient population, we found that IMRT-treated EC patients showed comparable clinical outcomes but with a lower incidence of GI toxicities compared with those treated with 3DCRT.

Clinical Observation of Three Dimensional Conformal Intensity-modulated Radiotherapy Combined with Cisplatin Chemotherapy and Nituzumab in the Treatment of Locally Advanced Nasopharyngeal Carcinoma

Objective . To observe the clinical effect of three-dimensional conformal intensity-modulated radiotherapy combined with cisplatin chemotherapy and nituzumab in the treatment of locally advanced nasopharyngeal carcinoma. Selection method. From January 2016 - January 2019 in fujian province third hospital treated 62 cases of patients with locally advanced nasopharyngeal carcinoma were selected as the research objects, which randomly divided into observation group (31 cases) and control group (31 cases). Control group were treated by three-dimensional conformal intensity modulated radiation therapy synchronous paclitaxel and cisplatin chemotherapy, observers group on the basis of control group, this bead sheet were given, and the treatment. Clinical efficacy and adverse reactions of 2 groups were compared. Results . The CR rate of nasopharyngeal primary foci 2 months after radiotherapy, the CR rate of cervical lymph node, the control rate of primary foci 1 year after radiotherapy . The rate of no distant metastasis in observation group were all higher than those in control group (P 0.05). Conclusion. Three-dimensional conformal intensity-modulated radiotherapy combined with cisplatin chemotherapy and nituzumab in the treatment of advanced nasopharyngeal carcinoma can improve the short-term efficacy, but in terms of improving the long-term efficacy and survival rate of patients, further follow-up investigation is needed.

Dosimetric comparison of three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and volumetric modulated arc therapy in high-risk prostate cancer

Dosimetric comparison of three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and volumetric modulated arc therapy in high-risk prostate cancer

Post-Operative Radiation Therapy for Non-Small Cell Lung Cancer: A Comparison of Radiation Therapy Techniques

Abstract Objectives Post-operative radiation therapy (PORT) in locally advanced non-small cell lung cancer (LA-NSCLC) has historically been associated with toxicity. Conformal techniques like intensity modulated radiation therapy (IMRT) have the potential to reduce acute and long-term toxicity from radiation therapy. Among patients receiving PORT for LA-NSCLC, we identified factors associated with receipt of IMRT and evaluated the association between IMRT and toxicity. Methods We queried the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between January 1, 2006 to December 31, 2014 to identify patients diagnosed with Stage II or III NSCLC and who received upfront surgery and subsequent PORT. Baseline differences between patients receiving 3-dimentional conformal radiation therapy (3D-CRT) and IMRT were assessed using the chi-squared test for proportions and the t-test for means. Multivariable logistic regression was used to identify predictors of receipt of IMRT and pulmonary, esophageal, and cardiac toxicity. Propensity-score matching was employed to reduce the effect of known confounders. Results A total of 620 patients met the inclusion criteria, among whom 441 (71.2%) received 3D-CRT and 179 (28.8%) received IMRT. The mean age of the cohort was 73.9 years and 54.7% were male. The proportion of patients receiving IMRT increased from 6.2% in 2006 to 41.4% in 2014 (P Conclusion In a cohort of elderly patients, the use of IMRT in the setting of PORT for LA-NSCLC was not associated with a difference in toxicity compared to 3D-CRT. This finding suggests that outcomes from PORT may be independent of radiotherapy treatment technique.

Investigation of 3D-Conformal and Intensity-Modulated Therapy Techniques to Determine the Absorbed Fetal Dose in Patients With Nasopharyngeal Cancer During Pregnancy

The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for nasopharyngeal cancers at various times during pregnancy. In this work, the head and neck cancer treatment of a pregnant patient was experimentally simulated. Two treatment plans were calculated using a female RANDO anthropomorphic phantom. This phantom was irradiated using the Clinac DHX linear accelerator, according to the Standard treatment plans of both three-dimensional conformal radiation therapy (3-DCRT) and IMRT techniques. During pregnancy, the height of the fundus at different weeks was determined and a sign was placed on the phantom. OSLD (optically stimulated luminescence dosimeter) and MOSFET (Metal oxide semiconductor field effect transistor) dosimeters were used to measure the dose of virtually designated uterus area at various times during pregnancy. The data carried out by TPS were compared with measured data. PBC calculation method in the treatment planning system (TPS) was unable to estimate the peripheral doses in uterus area. TPS showed a dose of 0 cGy at many points. On the contrary, OSLD measurement results revealed that the uterus (fetus) doses were ranging from 14.46–43.05 cGy (mean 27.9 ± 10.1 cGy) for 7-field IMRT treatment plan and 6,12–27,3 cGy (mean 14,7 ± 7,97 cGy) for 3-DCRT in Alderson anthropomorphic female RANDO phantom. MOSFET measurements showed that the uterus (fetus) doses were ranging from 15–50.1 cGy (mean 36.25 ± 11.7 cGy) for 7-field IMRT treatment plan and 10–36.3 cGy (mean 21.3 ± 9.54 cGy) for 3-DCRT treatment plan. All the observed fetal dose for the measurements and TPS data for two techniques are given in the Table below. In summary, comparing two techniques, it is clear that IMRT causes higher fetal radiation dose than 3-D CRT due to its higher MU value. Considering that fetal radiogenic effects are seen at 5-10 cGy (American Association of Physicists in Medicine Radiation Therapy Committee Task Group 36), 3-D CRT is a more reliable method. The TPS is unable to estimate peripheral doses accurately. Since the TPS underestimates the fetal dose, relying on the dose calculated by TPS does not seem possible under the current circumstances. The fetal dose from radiotherapy may vary depending on the gestational age at the time of treatment. The use of special shielding devices can considerably reduce the fetal dose from radiation therapy.Tabled 1Abstract 2597; TableIMRT3DMOSFETOSLDTPSMOSFETOSLDTPS12weeks15 cGy14.46cGy0.0cGy12weeks10cGy6.12cGy0.0cGy16 weeks32.2cGy22cGy0.0cGy16 weeks12.3cGy8.68cGy0.0cGy20-22 weeks32.55cGy23.1 cGy0.7cGy20-22 weeks15.6cGy10.5cGy0.0cGy24-26 weeks36.5 cGy25.69 cGy0.7cGy24-26 weeks21.5cGy12.25cGy0.0cGy28 weeks39.6 cGy27.09 cGy11cGy28 weeks23.4cGy14.03cGy0.0cGy36 weeks50.1 cGy43.05 cGy15cGy36 weeks36.3cGy27.3cGy9.7cGy40 weeks47.8 cGy40.01cGy11.6cGy40 weeks30cGy24.1cGy9.7cGy Open table in a new tab

3D-Conformal Radiation Therapy and IntensityModulated Radiation Therapy Techniques for Laryngeal Cancer Taking Parotid Glands as Organ at Risk

Background: Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques are used for the treatment of patients with laryngeal cancer. Objective: This study aimed to investigate the effects of these 2 treatment techniques on the planning target volume (PTV) (laryngeal cancer), dose homogeneity, dose of organs at risk (OARs) (parotid glands), and conformity index. Methods: This study compared 2 treatment techniques and was conducted from October 2018 to April 2019 at the Zhianawa Cancer Center (ZCC), Sulaimaniyah, Iraq. Eight patients with laryngeal cancer were selected for this study. 3D-CRT and IMRT were used to produce the maximum dose of target volume coverage and minimum dose to the parotid glands. Elekta synergy with a photon beam of 6 MV was used for all measurements. Data analysis was performed using the available statistical package of SPSS 25. Results: The comparison of 3D-CRT with IMRT showed that the mean conformity index value for IMRT was more conformal than the 3D-CRT plan (0.956, 0.945, respectively), but the homogeneity index was better with 3D-CRT than with IMRT (0.175, 0.202, respectively). The mean dose for Rt. parotid glands was higher with IMRT than with 3D-CRT (232.71, 23.26, respectively), and in both plans the mean dose was less than 26 Gy (the standard tolerance value). While in the Lt. parotid gland the mean dose was higher with 3D-CRT than with IMRT (26.95, 23.71, respectively), the mean dose with 3D-CRT was greater than 26 Gy. The amount of PTV was significantly greater with the IMRT technique than with 3D-CRT (52.15±1.61, 51.09.4±0.74 Gy, respectively). Conclusion: This study further supports that IMRT has improved the long-term quality of life of patients with laryngeal cancer.

Acute toxicity profile of three-dimensional conformal concurrent chemoradiation in carcinoma cervix: an institutional experience

AbstractBackground:Concurrent chemoradiation is the definitive treatment for advanced cervical cancer. Pelvic radiation is known to damage the adjacent normal tissues thereby causing acute toxicities. The modern conformal radiation techniques like three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy are known to reduce the toxicities and improve clinical outcomes.Aim:To retrospectively evaluate the frequency and severity of acute toxicities encountered during concurrent chemoradiation of locally advanced cancer cervix treated with 3D-CRT.Methods:The medical case records of 174 cervical cancer patients treated between November 2015 and November 2018 were studied. One hundred and thirteen histologically proven locally advanced cancer cervix patients (Stage IIB–IIIB) treated with concurrent 3D conformal chemoradiation between were included in the study. Patients received 46 Gy in 23 fractions with concurrent weekly cisplatin (40 mg/m2) on days 1, 8, 15 and 22 of radiation. The study endpoints were treatment-related toxicities which were graded according to CTCAE version 5.0.Results:One hundred and thirteen patients were analysed for the study. Gastrointestinal toxicity was the predominant toxicity observed followed by haematological toxicity. 31·7% patients reported grade 1–2 diarrhoea and 39·7% reported grade 1–2 leucopenia. None of the patients reported grade 3 or higher toxicities. Treatment interruptions were noted due to these toxicities.Conclusion:Concurrent chemoradiation is the definitive treatment for locally advanced carcinoma cervix with acceptable toxicities. Proper management measures should be undertaken for these toxicities to avoid treatment interruptions and ensure better treatment compliance.

COMPARISON OF INTENSITY-MODULATED RADIOTHERAPY (IMRT) AND 3D TANGENTIAL BEAMS TECHNIQUE USED AT PATIENTS WITH BREAST CANCER

Radiotherapy is one of the most effective treatments for breast cancer. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are two recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity and reducing toxicity to healthy organs. However, these advantages have not been demonstrated in the treatment of breast cancer. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of breast cancer in terms of dose-volume histograms and outcomes, including survival and toxicity.

Clinical observation of LOP chemotherapy combined with radiotherapy in the treatment of early nasal NK/T cell lymphoma

Objective:To investigate the efficacy and safety of LOP（asparaginase + vincristine + dexamethasone） chemotherapy combined with radiotherapy in patients with nasal NK/T cell lymphoma. Method:Sixty patients with nasal NK/T cell lymphoma admitted to our hospital from February 2012 to February 2016 were selected as the study subject. They were randomly divided into group A and group B, 30 cases in each group. All patients were treated with combined chemotherapy and IMRT（intensity modulated conformal radiotherapy）. The LOP regimen was used in group A and the CHOP（cyclophosphamide + pirarubicin + vincristine + dexamethasone） regimen was used in group B. The short-term efficacy, long-term efficacy and adverse reactions of the two groups were compared. Result:The clinical manifestations of 60 patients mainly included nasal obstruction（81.67%）, accompanied by fever, headache, nosebleed and runny nose. Forty-one patients（68.33%） had only one site of lesion, and 21 patients（35.00%） had multiple sites of lesions. In terms of total remission rate, it was significantly higher in group A than that in group B（93.33% vs. 66.67%, P<0.05）. In terms of adverse reactions, the incidence of bone marrow suppression, gastrointestinal reaction and low-protein reaction was significantly lower in group A than that in group B（P<0.05）. Three patients died in group A and 11 patients died in group B during the 3-year follow-up. The 3-year survival rate of group A was higher than that of group B（P<0.05）. Conclusion:Compared with CHOP+IMRT regimen, the LOP+IMRT regimen for nasal NK/T-cell lymphoma patients resulted in higher overall remission rate, survival rate and lower adverse reactions, so it is worth in clinical promotion.

A Comparison of Radiation Techniques in Patients Treated with Concurrent Chemoradiation for Stage III Non-Small Cell Lung Cancer

The standard of care in the management of stage III non-small cell lung cancer (NSCLC) is concurrent chemoradiation. Recently, newer more conformal techniques with intensity modulated radiation therapy (IMRT) and volumetric arc therapy (VMAT) are being used. It is unclear whether a more conformal technique ultimately improves survival in patients with stage III lung cancer. We looked at population-based data to examine this question. A retrospective cohort of stage III NSCLC patients treated with concurrent chemoradiation with curative intent between 2009-2014 in Ontario were identified from the ICES (Institute of Clinical Evaluative Sciences) database. Patients were excluded if they had surgery, sequential chemoradiation or radiation alone. Outcomes were compared for patients treated with 3D conformal radiation (3D-CRT), IMRT and VMAT. The primary endpoint was overall survival (OS), calculated using the Kaplan-Meier method and compared using log-rank test. Cox regression was used to investigate effect of radiation type on OS. A minimal clinically important difference (MCID) was set at ≥15%. Between 2009-2014, a total of 2507 patients were treated with 3D-CRT (N=925), IMRT (N=1227) or VMAT (N=355). The rate of 3D-CRT use declined (from 65% in 2009 to 14% in 2014) while the rates of IMRT (35% to 53%) and VMAT (0% to 33%) use concurrently increased. Median survival in months was 22.7 [95% CI 21.0-24.4] for 3D-CRT, 20.8 [95% CI 19.6-22.2] for IMRT and 24.3 [95% CI 20.6-27.9] for VMAT (p=0.041 for all 3 groups, and p=0.046 for 3D CRT vs IMRT alone). The 5 year OS was 22.1% [95% CI 19.2-25.1] for 3D-CRT vs 18.1% [95% CI 15.4-20.9] for IMRT (p=0.046). Prognostic factors for survival on multivariable analysis included male sex [HR 1.29, 95% CI 1.18-1.42, p <0.001], income quintile [HR 0.95, 95% CI 0.92-0.99, p = 0.004], age [HR 1.03, 95% CI 1.00-1.06, p = 0.04], and radiation type [IMRT HR=1.12, 95% CI 1.01-1.24; VMAT HR=0.91, 95% CI 0.76-1.09, p=0.012]. There is increased uptake of more conformal techniques over time amongst stage III NSCLC patients. Although a statistically significant difference in OS was observed, this was likely driven by unmeasured patient selection effects. Absolute differences were modest and did not meet clinical significance.

Estimation of radiation-induced second cancer risk associated with the institutional field matching craniospinal irradiation technique: A comparative treatment planning study

To estimate and compare the lifetime attributable risk (LAR) of radiation-induced second cancer (SC) in pediatric medulloblastoma patients planned with institutional 3D conformal field matching method, gap junction method and Intensity Modulated Radiotherapy (IMRT). The epidemiological studies on childhood cancer survivors reported that long-term cancer survivors who received radiotherapy are at a significantly increased risk for the development of SC. Hence, the increased concern to predict the SC risk for long-term survivors. In addition to institutional field matching planning method, IMRT and gap junction methods were created for ten pediatric medulloblastoma patients. The risk estimates were made based on the site-specific cancer risk coefficient provided by the BEIR VII committee according to the organ equivalent dose for various critical organs. Also, plans were compared for target volume dose distribution and dose received by critical organs. When compared to the gap junction method, the IMRT and institutional field matching method were superior in normal tissue sparing and dose conformity. However, highly significant volume of low dose associated with IMRT was the main concern for the SC risk. The accumulated LAR for all the critical organs with 3D conformal gap junction and IMRT method was 23-25% while for the 3D conformal field matching method it was 21%. The LAR associated with the institutional field matching technique was substantially lower. As this method is highly robust and easy to set up, it can be a better choice of a craniospinal irradiation technique where 3DCRT is the only choice of treatment.

Comparison of clinical efficacy and prognosis of intensity-modulated radiotherapy and three dimensional conformal radiotherapy in patients with stage II/III esophageal cancer: a multi-center retrospective analysis in Beijing, Tianjin and Hebei province (3JECROG R-06)

Objective To compare the therapeutic effects between three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in patients with stage Ⅱ/Ⅲ esophageal cancer and investigate the prognostic factors. Methods Medical record of 2 132 patients with stage Ⅱ/Ⅲ esophageal cancer who underwent definitive radiotherapy with/without chemotherapy in 10 hospitals from January 2002 to December 2016 from were retrospectively analyzed. Among these patients, 37.9% of them were aged≥70 years, 33.9% with neck and upper esophageal tumors and 66.1% with middle and lower esophageal and borderline tumors. The median gross tumor volume (GTV) and lymph node gross tumor volume (GTVnd) was 41.6 cm3.Among them, 32% were stage Ⅱ and 68% were stage Ⅲ.A total of 723 patients received 3DCRT and 1 409 cases received IMRT.Patients received an equivalent dose in 2 Gy (EQD2) ≥ 60 Gy accounted for 86.1%, and 41.1% of them received concurrent chemoradiotherapy. Results The median follow-up time was 60.8 months. The 1-, 3-and 5-year overall survival (OS) of all patients was 73.9%, 41.7% and 32.6%, and the 1-, 3-and 5-year progression-free survival (PFS) was 62.2%, 37.3% and 32%, respectively. Multivariate analysis demonstrated that age, primary tumor location, clinical stage, tumor target volume, EQD2 and concurrent chemoradiotherapy were the independent prognostic factors for OS.Age, primary tumor location, clinical stage, tumor target volume and EQD2 were the independent prognostic factors for PFS.The OS and PFS did not significantly differ among the low-risk, low-/moderate-risk, moderate-/high-risk and high-risk groups according to age≥70 years, tumor diameter>5 cm, tumor volume≥41.6 cm3 and stage Ⅲ(P<0.001). After the propensity score matching (PSM) method, neither 3DCRT nor IMRT yielded significant advantages in OS or PFS (P=0.971; P=0.658). However, IMRT tended to yield survival benefits in low-risk patients (P=0.125). Conclusions Both 3DCRT and IMRT yield relatively high OS rate in patients with stage Ⅱ/Ⅲ esophageal cancer. The prognosis model established in this investigation can properly predict the survival of patients. Low-risk patients tend to obtain survival benefits from IMRT. Key words: Esophageal neoplasm/three-dimensional conformal radiotherapy; Esophageal neoplasm/intensity-modulated radiotherapy; Prognosis

Neoadjuvant chemoradiotherapy combined with surgery in the treatment of potentially operable thoracic squamous cell carcinoma of the esophagus(ChiCTR-OIC-17011648): A phase II single center clinical study.

e15543 Background: To investigate the efficacy and safety of neoadjuvant radiotherapy and chemotherapy combined with surgery in the treatment of potentially operable thoracic esophageal squamous cell carcinoma. Methods: Nineteen patients with advanced thoracic esophageal squamous cell carcinoma hospitalized in our hospital from July 2016 to June 2018 were prospectively studied. All patients received neoadjuvant concurrent radiotherapy and chemotherapy: intensity modulated conformal radiotherapy (40 ∽ 44Gy/20 ∽22f, 2 Gy/f), chemotherapy (paclitaxel 150 ∽ 175 mg/m2 d1, 22+lobaplatin 25-30 mg/m2 d2, 23, 2 cycles). After radiotherapy and chemotherapy, the efficacy and safety of the operation were observed. Results: Two case (10.5%) was completely remitted after neoadjuvant radiotherapy and chemotherapy, 17 cases (89.5%) were partially remitted, and the objective effective rate was 100%. All patients underwent radical surgery successfully, the R0 resection rate was 100% and the pCR rate was 52.6%. The main adverse reactions of neoadjuvant radiotherapy and chemotherapy were granulocytopenia and grade III-IV granulocytopenia. The rate of survival was 16.7%, and anastomotic leakage occurred in 1 patients after operation. Conclusions: Neoadjuvant chemoradiotherapy for thoracic esophageal squamous cell carcinoma can effectively reduce the volume of the tumor, significantly reduce the pathological grade, improve the resection rate, and have less adverse reactions, which is worthy of clinical application. Clinical trial information: ChiCTR-OIC-17011648.

Evaluation of the Effect of Various Radiotherapy Modalities on Swallowing Function in Patients With Nasopharyngeal Cancer.

The objective of this study was to compare the effect of curative 3-dimensional (3D) conformal radio-chemotherapy and intensity-modulated radiotherapy (IMRT) modalities on swallowing function in patients with nasopharyngeal cancer. Ten patients receiving 3D conformal radiotherapy and 10 patients receiving curative radiotherapy with IMRT, who were admitted for malignancy control for nasopharyngeal cancer, were included in the study. Swallowing functions were determined by flexible fiberoptic endoscopic evaluation. Premature spillage, retention pooling, penetration, aspiration, and reflex cough were evaluated. No statistically significant difference was found between patients receiving 3D conformal radiotherapy and IMRT regarding the scores of premature spillage, retention pooling, penetration, and aspiration with 3, 5, and 10 mL water and 5 mL yoghurt and fish crackers (P > .05). Velopharyngeal insufficiency or delayed onset of swallowing reflex was not found in any of the patients (P > .05). No significant difference was found between the groups in terms of the symptoms regarding subjective evaluation of swallowing (P > .05). Swallowing function did not differ among patients receiving IMRT and 3D conformal radiotherapy. Further studies with a larger sample size are warranted in order to verify the results.

Comparison of conformal radiotherapy, intensity-modulated radiotherapy and tomotherapy irradiation techniques in prostate cancers

AbstractAimThe aim of this study is to compare three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and tomotherapy techniques used in the treatment of prostate cancer with target and critical organ doses to be included.Materials and MethodsThe target dose was studied with 4-and 6-field 3D-CRT, 7-field IMRT and tomotherapy techniques used to treat ten patients for prostate cancer and the dose volume histograms of critical organs were analyzed. The same target volumes, critical organs doses prescribed and treatment times for the three techniques were compared. Total dose of 76 Gy was given using 6 MV and 18 MV for 3D-CRT, 6 MV for IMRT and tomotherapy techniques.ResultsWhen we compare the three techniques, for rectum V35(p:0·001), V65(p:0·001), D50(p:0·020) and D25(p:0·002), for bladder V50(p:0·027), V65(p:0·006), V100(p:0·006) and for femoral head, the V50(p:0·001) dose was found to be significantly different and more favourable in the tomotherapy technique. Significant differences were found with IMRT planning in 50% of bladder volume (p:0·002). There is no significant difference between the three techniques for doses of 100% volume of rectum and 25% of volume of bladder. The minimum dose that healthy tissue received which was outside the tumour volume was investigated.FindingsDoses to critical organs were lower using the tomotherapy technique. However, the minimum doses that healthy tissue received were higher for the tomotherapy technique. When the beam on times were compared for all three techniques, a significant difference was found in favor of tomotherapy.

Complementary Relation Between the Improvement of Dose Delivery Technique and PTV Margin Reduction in Dose-Escalated Radiation Therapy for Prostate Cancer

PurposeThe purpose of this study is to demonstrate quantitatively the complementary relationship between the introduction of intensity modulated radiation therapy (IMRT) and planning target volume (PTV) margin reduction with an image guided technique in reducing the risk of rectal toxicity in dose-escalating prostate radiation therapy. Methods and MaterialsThree-dimensional conformal radiation therapy (CRT) and IMRT plans were generated for 10 patients with prostate cancer based on 2 PTV margin protocols (10/8 mm and 6/5 mm) and 2 dose prescriptions (70 Gy and 78 Gy). The normal tissue complication probability (NTCP) for each of the 8 scenarios was calculated using the Lyman-Kutcher-Burman model to estimate the risk of rectal and bladder late toxicity. The conformity and homogeneity indices of PTVs were calculated for each plan. ResultsThe IMRT plans showed superiority in conformity and inferiority in homogeneity over 3-dimensional CRT plans. The rectal NTCPs were increased 3.5 to 4.1 times when the prescribed total dose was changed from 70 Gy to 78 Gy and the dose delivery and the image guided radiation therapy techniques remained unchanged. PTV margin reduction was shown to reduce the value of rectal NTCP significantly. Overall, implementing the IMRT technique alone could reduce the NTCP values only by 2.1% to 7.3% from those of 3-dimensional CRT. The introduction of both IMRT and PTV margin reduction was found to be necessary for rectal NTCP to remain <5% in the dose escalation from 70 to 78 Gy. ConclusionsThe complementary relationship between the introduction of IMRT and PTV margin reduction was proven. We found that both approaches need to be implemented to safely deliver a curative dose in dose-escalating prostate radiation therapy.

Influence of 3D-CRT and conformal IMRT on thyroid function of patients with cervical and upper thoracic esophageal cancer and comparison of clinical efficacy.

Clinical efficacy in patients with cervical and upper thoracic esophageal cancer was compared between three-dimensional conformal radiotherapy (3D-CRT) and conformal intensity-modulated radiotherapy (IMRT). Medical data of 120 esophageal cancer patients undergoing RT in the Radiology Department in Xiaogan Hospital Affiliated to Wuhan University of Science and Technology (Xiaogan, China) from March 2015 to March 2018 were retrospectively analyzed. Patients were divided into 3D-CRT group (treated with 3D-CRT, n=60) and IMRT group (treated with IMRT, n=60). The target conformal index (CI), PTV maximum dose (Dmax), PTV Dmin and PTV Dmean in both groups were observed. Changes in double-lung V5, double-lung V20, double-lung V30 and spinal cord Dmax in both groups were also observed. The serum free triiodothyronine (FT3), free tetraiodothyronine (FT4) and thyroid-stimulating hormone (TSH) concentrations were detected via chemiluminescence assay. Moreover, the short-term efficacy and radiation injury were observed. CI in IMRT group was significantly higher than that in 3D-CRT group (P<0.001). The organ-at-risk dose parameter V20 in IMRT group was obviously lower than that in 3D-CRT group (P<0.001). Serum FT3 and FT4 concentrations in both groups before RT were significantly higher than those after RT (P<0.05), but the TSH concentration was significantly lower than that after RT (P<0.05). Serum FT3 and FT4 concentrations in IMRT group after RT were obviously higher than those in 3D-CRT group (P<0.05). The incidence rates of radiation esophagitis and radiation pneumonitis in IMRT group were remarkably lower than those in 3D-CRT group (P<0.05). IMRT can reduce the double-lung V20 in patients, improve the target conformal degree, better protect the normal tissues, cause less damage to thyroid function, and reduce radiation injury during and after RT of esophageal cancer.

Prognostic analysis of definitive three-dimensional radiotherapy for non-surgically resectable esophageal squamous cell carcinoma: a multi-center retrospective study (3JECROG R-01)

Objective To evaluate the survival and prognostic factors of esophageal cancer treated with definitive (chemo) radiotherapy by applying novel radiation techniques including three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT). Methods Clinical data of 2762 patients with non-operated esophageal squamous cell carcinoma who underwent definitive (chemo) radiotherapy from 2002 to 2016 in 10 hospitals were retrospectively analyzed.The prognostic factors were also identified and analyzed. Results The median follow-up time was 60.8 months.The 1-, 2-, 3-and 5-year overall survival (OS) of all patients was 71.4%, 48.9%, 39.3%, and 30.9%, respectively.The 1-, 2-, 3-and 5-year progression-free survival (PFS) was 59.5%, 41.5%, 35.2%, and 30%, respectively.The median survival was 23 months.The median time to progression was 17.2 months.Multivariate analysis demonstrated that age, primary tumor location, clinical stage, tumor target volume, EQD2 and treatment mode were the independent prognostic factors for OS.Primary tumor location, clinical stage, tumor target volume and EQD2 were the independent prognostic factors for PFS. Conclusions In this first large-scale multi-center retrospective analysis of definitive (chemo) radiotherapy for esophageal squamous cell carcinoma in China, the 5-year OS of patients with esophageal squamous cell carcinoma is significantly improved by 3DCRT, IMRT combined with chemotherapy drugs. However, the findings remain to be validated by prospective clinical trials with high-level medical evidence. Key words: Esophageal neoplasm/radiotherapy; Esophageal neoplasm/chemotherapy; Prognosis