A randomized controlled trial comparing the efficacy and toxicities between neoadjuvant concomitant boost intensity-modulated radiotherapy(IMRT) and 3-dimensional conformal radiotherapy (3-DCRT) for locally advanced rectal cancer

Despite technological advances in radiation therapy (RT) and cancer treatment, patients still experience adverse effects. Proton therapy (PT) has emerged as a valuable RT modality that can improve treatment outcomes. Normal tissue injury is an important determinant of the outcome; therefore, for this review, we analyzed 2 databases: (1) clinical trials registered with ClinicalTrials.gov and (2) the literature on PT in PubMed, which shows a steady increase in the number of publications. Most studies in PT registered with ClinicalTrials.gov with results available are nonrandomized early phase studies with a relatively small number of patients enrolled. From the larger database of nonrandomized trials, we listed adverse events in specific organs/sites among patients with cancer who are treated with photons and protons to identify critical issues. The present data demonstrate dosimetric advantages of PT with favorable toxicity profiles and form the basis for comparative randomized prospective trials. A comparative analysis of 3 recently completed randomized trials for normal tissue toxicities suggests that for early stage non-small cell lung cancer, no meaningful comparison could be made between stereotactic body RT and stereotactic body PT due to low accrual (NCT01511081). In addition, for locally advanced non-small cell lung cancer, a comparison of intensity modulated RTwith passive scattering PT (now largely replaced by spot-scanned intensity modulated PT), PT did not provide any benefit in normal tissue toxicity or locoregional failure over photon therapy. Finally, for locally advanced esophageal cancer, proton beam therapy provided a lower total toxicity burden but did not improve progression-free survival and quality of life (NCT01512589). The purpose of this review is to inform the limitations of current trials looking at protons and photons, considering that advances in technology, physics, and biology are a continuum, and to advocate for future trials geared toward accurate precision RT that need to be viewed as an iterative process in a defined path toward delivering optimal radiation treatment. A foundational understanding of the radiobiologic differences between protons and photons in tumor and normal tissue responses is fundamental to, and necessary for, determining the suitability of a given type of biologically optimized RT to a patient or cohort.

Management of Intestinal Complications in Patients With Pelvic Radiation Disease

Acute and Late Radiation-Related Toxicity After Treatment of Locally Advanced Rectal Cancer With Intensity Modulated Radiation Therapy Compared With 3-Dimensional Conformal Radiation Therapy in the RAPIDO Trial.

Recent studies have suggested differing toxicity patterns for patients with prostate cancer who receive treatment with 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), or proton beam therapy (PBT). The authors reviewed patient-reported outcomes data collected prospectively using validated instruments that assessed bowel and urinary quality of life (QOL) for patients with localized prostate cancer who received 3DCRT (n = 123), IMRT (n = 153) or PBT (n = 95). Clinically meaningful differences in mean QOL scores were defined as those exceeding half the standard deviation of the baseline mean value. Changes from baseline were compared within groups at the first post-treatment follow-up (2-3 months from the start of treatment) and at 12 months and 24 months. At the first post-treatment follow-up, patients who received 3DCRT and IMRT, but not those who received PBT, reported a clinically meaningful decrement in bowel QOL. At 12 months and 24 months, all 3 cohorts reported clinically meaningful decrements in bowel QOL. Patients who received IMRT reported clinically meaningful decrements in the domains of urinary irritation/obstruction and incontinence at the first post-treatment follow-up. At 12 months, patients who received PBT, but not those who received IMRT or 3DCRT, reported a clinically meaningful decrement in the urinary irritation/obstruction domain. At 24 months, none of the 3 cohorts reported clinically meaningful changes in urinary QOL. Patients who received 3DCRT, IMRT, or PBT reported distinct patterns of treatment-related QOL. Although the timing of toxicity varied between the cohorts, patients reported similar modest QOL decrements in the bowel domain and minimal QOL decrements in the urinary domains at 24 months. Prospective randomized trials are needed to further examine these differences.

Intensity Modulated Radiation Therapy Replaces 3-Dimensional Conformal Radiotherapy as Prostate Cancer Treatment

Minimal Vaginal Displacement With Use of a Rectal Balloon During Pelvic IMRT for Gynecologic Malignancies

Effectiveness of noncoplanar IMRT planning using a parallelized multiresolution beam angle optimization method for paranasal sinus carcinoma

Purpose：The aim of this study was to compare the dose distribution of intensity modulated radiation therapy (IMRT) with 3 dimensional conformal radiation therapy (3DCRT) in prostate cancer. Materials and Methods：The IMRT plan and the 3DCRT plan used the 9 fields technique, respectively. In IMRT, tumor dose was a total dose of 50 Gy at 2.0 Gy per day, 5 days a week for 5 weeks. All cases were following the dose volume histogram (DVH) constraints. The maximum and minimum tumor dose constraints were 5,075 cGy and 4,925 cGy, respectively. The rectum dose constraints were <35% over 40 Gy. The bladder dose constraints were <35% over 30 Gy. The femur head dose constraints were <15% over 16 Gy. Tumor dose in the 3DCRT were 50 Gy. Results：In IMRT, the maximum dose of PTV was 101.9% and minimum dose was 89.5% for given dose. In 3DCRT, the maximum dose of PTV was 103.5% and minimum dose was 86.5% for given dose. The rectum dose was 29.2% over 40 Gy in IMRT compared with 67.9% in 3DCRT. The bladder dose was 30.1% over 30 Gy in IMRT compared with 30.6% in 3DCRT. The right femur head dose was 5.3% over 16 Gy in IMRT compared with 8.3% in 3DCRT. The left femur head dose was 6.8% over 16 Gy in IMRT compared with 9.1% in 3 DCRT. Conclusion：The dose of critical organs (rectum, bladder, and femur head) in IMRT showed to reduce than dose of 3DCRT. The rectum dose over 40 Gy in IMRT was reduced 38.7% than 3DCRT. The bladder dose over 30 Gy in IMRT was similar to 3DCRT. The femur head dose over 16 Gy in IMRT was reduced about 2.3∼3% than 3DCRT.

Objective To retrospectively analyze the clinical efficacy of three dimensional conformal radiotherapy and intensity modulated radiation therapy on postoperative patients with cervical cancer. Methods Seventy-eight cases of cervical cancer patients were treated with radical hysterectomy. According to the postoperative radiotherapy plan, the patients were divided into the observation group and the control group, with 39 cases in each group. The observation group received intensity modulated radiation therapy, and the control group received three-dimensional conformal radiotherapy after operation. The planning target volume (PTV) indexes [minimum radiation dose (Dmin), maximum irradiation dose (Dmax), mean radiation dose (Dmean), conformal index (95%CI), uniformity index (HI)], the percentage of irradiated volume under the organs at risk (OAR) prescription dose V45 level, the incidence of adverse reaction during chemotherapy and the recurrence rate of cervical cancer during the period of follow-up between the two groups were compared. Results ①PTV dosimetric indicators: the Dmin and Dmean in the observation group were lower than those in the control group, and 95%CI was higher than that in the control group(P 0.05). ②The percentage of irradiated volume under the OAR prescription dose V45 level: at the prescribed dose of V45, the percentage of radiation volume in the bladder, rectum, small intestine, bone marrow and femoral head of the observation group was lower than that of the control group(P 0.05). ④Prognosis: there was no significant difference in the 1-year recurrence rate [2.56%(1/39) vs. 7.69%(3/39)] or 2-year recurrence rate [7.69%(3/39) vs. 12.82%(5/39)] between the observation group and the control group(P>0.05). Conclusions Compared with the three dimensional conformal radiotherapy, IMRT can achieve better target dose distribution, and to some extent, it can reduce the volume of irradiated organs at risk. It is helpful to reduce the incidence of adverse reaction such as bone marrow suppression, but it has no significant advantage on the recurrence rate of cervical cancer. Key words: Radical hysterectomy; Three dimensional conformal radiotherapy; Intensity modulated radiation therapy; Safety; Prognosis

Effects of 3-Dimensional Conformal or Intensity-modulated Radiotherapy on Dental Pulp Sensitivity during and after the Treatment of Oral or Oropharyngeal Malignancies

Objective To compare the homogeneity and conformity of dose distribution in the target and the dose to the organs at risk among 3-dimensional conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and simplified intensity modulated radiation therapy (sIMRT), and then to evaluate the clinical value of sIMRT for cervical cancer. Methods Ten patients with cervical canc-er receiving radical radiotherapy and brachytherapy were enrolled. Before radiotherapy, CT was performed and target volumes were delineated. The clinical target volume (CTV) included supravaginal portion, cervi-cal stump, paracervical tissue, common iliac lymph nodes, internal and external iliac lymph nodes, obtura-tor lymph nodes, sacral lymph nodes, and the surrounding tissues. If the vagina was involved, the target vol-ume included the whole vagina. Margins between planning target volume (PTV) and CTV were 10 mm in the anterior direction, and 5 mm in other directions. The prescribed dose was 95% PTV receiving 45 Gy in 25 fractions of 1.8 Gy. The dose volume histogram, conformity index, homogeneity index and treatment time per faction were compared. Results Among the three radiotherapy techniques, 3DCRT had the best homo-geneity of dose distribution, while there was no significant difference between IMRT and slMRT. According to the conformity of dose distribution, sIMRT was better than 3DCRT, but worse than IMRT. Comparing the bladder sparing, IMRT was the best followed by sIMRT. The volume of the small intestine receiving high dose was increased significantly with slMRT when compared with IMRT. And the treatment time per faction was4, 10 and 18 minutes for3 DCRT, sIMRT and IMRT, respectively. Conclusions sIMRT could re-duce the work intensity of the staff, shorten the treatment time per fraction, and simplify the authenticate procedure, which is cost-effective and suitable in the treatment of cervical cancer. Key words: Cervical neoplasms/radiotherapy; Radiotherapy, simplified intensity-modulated; Dosimetry

Purpose: To quantify the incidental radiation dose delivered to axilla and internal mammary nodal (IMN) area by Conventional Tangential Radiation Therapy (CRT), 3 Dimensional Conformal Radiation Therapy (3DCRT) and Intensity Modulated Radiation Therapy (IMRT). Methods and Materials: We prospectively evaluated incidental radiation to axilla in twenty cases of breast cancer treated with adjuvant radiation therapy. Three plans were generated for each case, comprising CRT, 3DCRT and IMRT tangents. Radiation doses to axillary levels I, II, III, and IMN areas were evaluated for mean dose, V95, V80 and V50. Comparisons were made using ANOVA. Results: The mean volume and range of the axillary level I, II, III, and IMN were 61.1 cc and 142-57 cc; 42.6 cc and 61-21cc; 19.5 cc and 34-15 cc; 13.2 cc and 21-9 cc respectively. The mean dose to axilla by 3 techniques (by IMRT, 3DCRT and CRT) to Level I, II, III, and IMN were 75%, 53%, 38%, and 61% vs. 81%, 64%, 44% and 77% vs. 92%, 86%, 53% and 92% respectively (p<0.05). The V95 values (volume receiving 95% of dose) for the three techniques were 43%, 39%, 17% and 49% by IMRT: 40%, 45%, 21% and 59% by 3DCRT; 72%, 61%, 24% and 65% by CRT (IMRT vs. 3DCRT for level II axilla, IMRT vs. CRT and 3DCRT vs. CRT-p<0.05) The V80 were 49%, 53%, 29%, and 57% by IMRT; 55%, 47%, 34% and 68% by 3DCRT; 85%, 77%, 44% and 69% by CT (IMRT vs. 3DCRT for level III axilla and IMN, IMRT vs. CRT and 3DCRT vs. CRT -p<0.05). The V50 values were 75%, 65%, 41% and 66% by IMRT; 82%, 53%, 57% and 84% by 3DCRT; 94%, 89%, 42% and 90% by CRT (IMRT vs. 3DCRT, IMRT vs. CRT, and 3DCRT vs. CRP–p<0.05). Conclusion: Axillary and internal mammary nodal areas receive substantial amount of incidental radiation doses with all the three techniques; however, conformal techniques (IMRT, 3DCRT) deliver significantly lesser incidental radiation to lower axilla than CRT technique.

Objective To explore the clinical efficacy of intensity-modulated radiotherapy combined with chemotherapy in the treatment of advanced cervical cancer. Methods All 121 patients with advanced cervical cancer (stage ⅡB & ⅢA & ⅢB) selected in our hospital from June 2012 to June 2014, who were treated with combined chemoradiotherapy, were divided into observation group [intensity modulated radiation therapy (IMRT)group)] and control group [3-dimensional conformal radiation therapy (3D-CRT) group]. There was no significant difference between two groups in mean age, body mass index, International Federation of Gynecology and Obstetrics (FIGO) clinical stage, pathological type and chemotherapy mode (P>0.05). The clinical features of two groups were compared. The treatment and follow-up of two groups were recorded. Results The bone marrow suppression [32.2%(19/59) vs 51.6%(32/62)], gastrointestinal reaction [42.4%(25/59) vs 62.9%(39/62)], and rectal reaction rate [27.1%(16/59) vs 45.2%(28/62)] of the observation group were significantly less than that of the control group (P 0.05). Two groups were followed up for 3 years, the local control rate of the observation group was significantly higher than that of the control group (86.3% vs 70.1%) (P<0.05). Conclusions IMRT combined with chemotherapy in the treatment of advanced cervical cancer can improve the local control rate of tumor, protect the endangered organ, and reduce the side effects of radiotherapy. Key words: Uterine cervical neoplasms/DT/RT; Cisplatin/AD; Radiotherapy, intensity-modulated; Combined modality therapy

Intensity modulated radiation therapy reduces gastrointestinal toxicity in locally advanced pancreas cancer

Purpose: To investigate if intensity modulated radiation therapy (IMRT) offers a better planning target volume (PTV) coverage and/or lower dose to normal thoracic structures in comparison to three dimensional conformal radiation therapy (3DCRT) in the treatment of mid and lower oesophageal carcinoma patients. Materials and Methods: A prospective study in the period from 2014 till 2015 was held in the radiation therapy department of the National Cancer Institute, Cairo University, in which 20 locally advanced or inoperable mid and lower oesophageal cancer patients were treated by chemo-radiation using 3DCRT technique. IMRT plans were generated for those 20 patients. The 3DCRT and IMRT plans were compared as regards PTV coverage and doses to critical organs at risk. Results: All plans had produced satisfactory PTV coverage with no significant differences noted. The lung V20 for both lungs in 3DCRT was 16.94% ± 4.2% which was increased to 21.42% ± 3.6% in IMRT (p = 0.017). The mean dose to the heart and V30 were higher in IMRT plans while the mean dose to the spinal cord was higher with 3DCRT plans, yet that didn’t reach a statistically significant level (p = 0.156). The dose delivered to the liver didn’t pose any difference between both techniques. Conclusion: 3DCRT remains to be a feasible cost effective treatment delivery option for mid and lower oesophageal cancer cases with a lower optimization and delivery time than that for IMRT. Moreover, that calls for further dosimetric studies and clinical trials to assess IMRT technique. In our study, IMRT using nine fields didn’t prove to be superior to 3DCRT.