Adaptive radiotherapy in locally advanced esophageal cancer with atelectasis: a case report

BACKGROUND: To the best of our knowledge, no study has reported mediastinal shift accompanied with obstructive atelectasis due to bulky primary esophageal tumor components treated with adaptive radiotherapy and concurrent chemotherapy. CASE PRESENTATION: Here we report the case of a 65-year-old male patient diagnosed with locally advanced thoracic esophageal squamous cell cancer, clinical T4bN1M0, stage IVA. Bronchoscopy and computed tomography (CT) revealed an almost complete obstruction of the lumen of the left bronchus due to compression by bulky primary esophageal tumor components. On admission, the patient presented with dyspnea and decreased arterial oxygen saturation. Chest radiography and CT on admission revealed mediastinal shift with left atelectasis, as opposed to findings from the chest radiography performed 26 days before admission. Because of the patient's overall good condition, we recommended definitive chemoradiotherapy instead of palliative bronchial stent placement. After obtaining the patient's consent, chemoradiotherapy was initiated on the following day and it comprised three-dimensional conformal radiotherapy with 60 Gy in 30 fractions with concurrent administration of cisplatin and 5-fluorouracil. During chemoradiotherapy, tumor location was monitored with cone-beam CT and chest radiography. Chemoradiotherapy on day 8 revealed no evidence of the mediastinal shift. CT simulation was reperformed to adjust the radiotherapy fields to account for geometrical changes induced by the absence of the mediastinal shift. Subsequently, the mediastinal shift and bronchial obstruction did not recur during the course of chemoradiotherapy. The patient completed the planned radiotherapy with concurrent and adjuvant chemotherapy, and no non-hematological grade ≥ 3 adverse events were observed. Complete response was confirmed 7 months after initiating chemoradiotherapy. Currently, no disease recurrence, dysphagia, or respiratory symptoms have been reported at 13 months after initiating chemoradiotherapy. CONCLUSIONS: In this study, a bulky primary esophageal tumor caused mediastinal shift due to ipsilateral bronchial obstruction. The close follow-up for monitoring resolution of the mediastinal shift during the course of chemoradiotherapy enabled adequate dose delivery to targets, thus reflecting the geometrical changes induced by the absence of the mediastinal shift. Adaptive radiotherapy technique was crucial for favorable patient outcomes in this challenging clinical situation

Preoperative chemoradiotherapy for locally advanced low rectal cancer using intensity-modulated radiotherapy to spare the intestines: a single-institutional pilot trial

The irradiated volume of intestines is associated with gastrointestinal toxicity in preoperative chemoradiotherapy for rectal cancer. The current trial prospectively explored how much of the irradiated volume of intestines was reduced by intensity-modulated radiotherapy (IMRT) compared with 3-dimensional conformal radiotherapy (3DCRT) and whether IMRT might alleviate the acute gastrointestinal toxicity in this population. The treatment protocol encompassed preoperative chemoradiotherapy using IMRT plus surgery for patients with clinical T3–4, N0–2 low rectal cancer. IMRT delivered 45 Gy per 25 fractions for gross tumors, mesorectal and lateral lymph nodal regions, and tried to reduce the volume of intestines receiving 15 Gy (V₁₅ Gy) < 120 cc and V₄₅ Gy ≤ 0 cc, respectively, while keeping target coverage. S-1 and irinotecan were concurrently administered. Acute gastrointestinal toxicity, rates of clinical downstaging, sphincter preservation, local regional control (LRC) and overall survival (OS) were evaluated. Twelve enrolled patients completed the chemoradiotherapy protocol. The volumes of intestines receiving medium to high doses were reduced by the current IMRT protocol compared to 3DCRT; however, the predefined constraint of V15 Gy was met only in three patients. The rate of ≥ grade 2 gastrointestinal toxicity excluding anorectal symptoms was 17%. The rates of clinical downstaging, sphincter preservation, three-year LRC and OS were 75%, 92%, 92% and 92%, respectively. In conclusion, preoperative chemoradiotherapy using IMRT for this population might alleviate acute gastrointestinal toxicity, achieving high LRC and sphincter preservation; although further advancement is required to reduce the irradiated volume of intestines, especially those receiving low doses

Reducing variability among treatment machines using knowledge‐based planning for head and neck, pancreatic, and rectal cancer

PURPOSE: This study aimed to assess dosimetric indices of RapidPlan model-based plans for different energies (6, 8, 10, and 15 MV; 6- and 10-MV flattening filter-free), multileaf collimator (MLC) types (Millennium 120, High Definition 120, dual-layer MLC), and disease sites (head and neck, pancreatic, and rectal cancer) and compare these parameters with those of clinical plans. METHODS: RapidPlan models in the Eclipse version 15.6 were used with the data of 28, 42, and 20 patients with head and neck, pancreatic, and rectal cancer, respectively. RapidPlan models of head and neck, pancreatic, and rectal cancer were created for TrueBeam STx (High Definition 120) with 6 MV, TrueBeam STx with 10-MV flattening filter-free, and Clinac iX (Millennium 120) with 15 MV, respectively. The models were used to create volumetric-modulated arc therapy plans for a 10-patient test dataset using all energy and MLC types at all disease sites. The Holm test was used to compare multiple dosimetric indices in different treatment machines and energy types. RESULTS: The dosimetric indices for planning target volume and organs at risk in RapidPlan model-based plans were comparable to those in the clinical plan. Furthermore, no dose difference was observed among the RapidPlan models. The variability among RapidPlan models was consistent regardless of the treatment machines, MLC types, and energy. CONCLUSIONS: Dosimetric indices of RapidPlan model-based plans appear to be comparable to the ones based on clinical plans regardless of energies, MLC types, and disease sites. The results suggest that the RapidPlan model can generate treatment plans independent of the type of treatment machine

Hypofractionated stereotactic radiotherapy for acoustic neuromas: safety and effectiveness over 8 years of experience.

Little information is available about long-term outcomes of hypofractionated stereotactic radiotherapy (hypo-FSRT) for acoustic neuromas. In this study, the safety and effectiveness of hypo-FSRT for unilateral acoustic neuroma were reviewed over 8 years of experience at our institution

限局型胚腫治療における強度変調放射線治療を利用した全脳室照射の有効性

京都大学0048新制・課程博士博士(医学)甲第16722号医博第3670号新制||医||992(附属図書館)29397京都大学大学院医学研究科医学専攻(主査)教授 小野 公二, 教授 宮本 享, 教授 富樫 かおり学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

Dosimetric advantage of intensity-modulated radiotherapy for whole ventricles in the treatment of localized intracranial germinoma.

Purpose : To investigate the dosimetric advantage of intensity-modulated radiotherapy (IMRT) for whole ventricles (WV) in patients with a localized intracranial germinoma receiving induction chemotherapy. Methods and Materials : Data from 12 consecutive patients with localized intracranial germinomas who received induction chemotherapy and radiotherapy were used. Four-field coplanar three-dimensional conformal radiotherapy (3D-CRT) and seven-field coplanar IMRT plans were created. In both plans, 24 Gy was prescribed in 12 fractions for the planning target volume (PTV) involving WV and tumor bed. In IMRT planning, optimization was conducted to reduce the doses to the organs at risk (OARs) as much as possible, keeping the minimum dose equivalent to that of 3D-CRT. The 3D-CRT and IMRT plans were compared in terms of the dose–volume statistics for target coverage and the OARs. Results : IMRT significantly increased the percentage volume of the PTV receiving 24 Gy compared with 3D-CRT (93.5% vs. 84.8%; p = 0.007), while keeping target homogeneity equivalent to 3D-CRT (p = 0.869). The absolute percentage reduction in the irradiated volume of the normal brain receiving 100%, 75%, 50%, and 25% of 24 Gy ranged from 0.7% to 16.0% in IMRT compared with 3D-CRT (p < 0.001). No significant difference was observed in the volume of the normal brain receiving 10% and 5% of 24 Gy between IMRT and 3D-CRT. Conformation number was significantly improved in IMRT (p < 0.001). For other OARs, the mean dose to the cochlea was reduced significantly in IMRT by 22.3% of 24 Gy compared with 3D-CRT (p < 0.001). Conclusions : Compared with 3D-CRT, IMRT for WV improved the target coverage and reduced the irradiated volume of the normal brain in patients with intracranial germinomas receiving induction chemotherapy. IMRT for WV with induction chemotherapy could reduce the late side effects from cranial irradiation without compromising control of the tumor

Intensity-modulated radiotherapy for cervical esophageal squamous cell carcinoma without hypopharyngeal invasion: dose distribution and clinical outcome

Hypopharyngeal invasion would be a key finding in determining the extent of the irradiation fields in patients with cervical esophageal squamous cell carcinoma (CESCC). This study aimed to investigate the clinical outcomes of chemoradiotherapy using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) omitting upper cervical lymph nodal irradiation in CESCC without hypopharyngeal invasion, and the dosimetric superiority of SIB-IMRT to 3D conformal radiotherapy (3DCRT). We retrospectively identified 21 CESCC patients without hypopharyngeal invasion [clinical Stage I/II/III/IV (M1LYM); 3/6/5/7] (UICC-TNM 7th edition) who underwent chemoradiotherapy using SIB-IMRT between 2009 and 2015. SIB-IMRT delivered 60 Gy to each primary tumor and the metastatic lymph nodes, and 48 Gy to elective lymph nodal regions, including Levels III and IV of the neck, supraclavicular, and upper mediastinal lymphatic regions, in 30 fractions. The overall survival rate, locoregional control rate, and initial recurrence site were evaluated. 3DCRT plans were created to perform dosimetric comparisons with SIB-IMRT. At a median follow-up of 64.5 months, the 5-year locoregional control and overall survival rates were 66.7% and 53.4%, respectively. Disease progressed in eight patients: all were locoregional progressions and no patients developed distant progression including upper cervical lymph nodal regions as initial recurrence sites. The planning study showed SIB-IMRT improved target coverage without compromising the dose to the organs at risk, compared with 3DCRT. In conclusion, omitting the elective nodal irradiation of the upper cervical lymph nodes was probably reasonable for CESCC patients without hypopharyngeal invasion. Locoregional progression remained the major progression site in this population

Initial and cumulative recurrence patterns of glioblastoma after temozolomide-based chemoradiotherapy and salvage treatment: a retrospective cohort study in a single institution

[Purpose]To analyze initial recurrence patterns in patients with newly diagnosed glioblastoma after radiotherapy plus concurrent and adjuvant temozolomide, and to investigate cumulative recurrence patterns after salvage treatment, including surgery, stereotactic radiotherapy, and chemotherapy. [Methods]Twenty-one patients with glioblastoma that recurred after concurrent temozolomide and localized radiotherapy were retrospectively analyzed (11 male, 10 female; median age, 57 years; range, 27–74). Disease progression was assessed by new response criteria proposed by the Response Assessment in Neuro-Oncology Working Group of the American Society of Clinical Oncology. The pattern of recurrence was determined by relationships between locations of recurrent tumors and irradiated doses. Central, in-field, marginal, and out-field recurrences were defined relative to the prescribed isodose line. Distant recurrence was operationally defined as subependymal or disseminated disease. Initial and cumulative patterns of recurrence were evaluated in each patient. [Results]The median follow-up of the recurrent patients was 501 (range, 217–1815) days after initial surgery. Initial recurrences were central in 14 patients (66.7%), in-field in four patients (19.0%), marginal in no patient (0%), out-field in two patients (9.5%), and distant in four patients (19.0%). One patient had both central and in-field recurrences simultaneously, and two had both central and distant recurrences. In the analysis of cumulative recurrence patterns, five patients, who had no scans after initial recurrences, were excluded and the remaining 16 were included. Cumulative recurrences were central in 11 patients (68.8%), in-field in five patients (31.3%), marginal in three patients (18.8%), out-field in five patients (31.3%), and distant in 14 patients (87.5%). Regarding salvage treatments, 11 (52.4%), 11 (52.4%) and 17 (81.0%) patients underwent surgery, stereotactic radiotherapy and chemotherapy, respectively. Eighteen (85.7%) patients had died at the time of analysis, and 16 of them (88.9%) had suffered distant recurrences, which could have been the immediate causes of death. [Conclusions]Recurrence patterns of glioblastoma after radiotherapy plus concomitant and adjuvant temozolomide were mainly central at first, and distant recurrences were often detected during the clinical course. Much better local control and prevention of distant recurrence, including effective salvage treatment, seem to be important

Outcomes of hypofractionated stereotactic radiotherapy for metastatic brain tumors with high risk factors.

The present study aimed to analyze outcomes of hypofractionated stereotactic radiotherapy (HFSRT) delivered in five fractions to metastatic brain tumors. Between June 2008 and June 2011, 39 consecutive patients with 46 brain metastases underwent HFSRT at Kyoto University Hospital. Selection criteria included high risk factors such as eloquent location, history of whole-brain radiotherapy (WBRT), or large tumor size. Given these factors, fractionated schedules were preferable in terms of radiobiology. The prescribed dose at the isocenter was basically 35 Gy in five fractions. Brainstem lesions with a history of WBRT were treated with 20-25 Gy in five fractions. Planning target volume was covered by the 80 % isodose line of the prescribed dose to the isocenter. Local-control probability and overall survival were estimated using the Kaplan-Meier method. For the analysis of local control, the response criteria were defined as follows: complete response (CR) was defined as no visible gross tumor or absence of contrast enhancement, partial response (PR) as more than a 30 % decrease in size, progressive disease as more than a 20 % increase in size, and stable disease (SD) as all other responses. Local control was defined as a status of CR, PR, or SD. Only patients with at least 3 months or longer follow-up (21 patients, 27 tumors) were included in the analysis. Median age and Karnofsky performance status were 59 years (range, 39-84 years) and 90 (range, 40-100), respectively. Tumor volumes and maximum diameters ranged from 0.08 to 15.38 cm(3) (median, 3.67 cm(3)) and from 3 to 34 mm (median, 18 mm), respectively. The median follow-up period was 329 days (range, 120-1, 321 days). Local-control probabilities at 6 and 12 months were 92.1 and 86.7 %, respectively. Overall survival after HFSRT at 6 and 12 months was 85.4 and 64.5 %, respectively. Grade 3 radiation necrosis was observed in one patient according to the Common Terminology Criteria for Adverse Events version 3.0. The patient was successfully managed conservatively. HFSRT for metastatic brain tumors yields high local-control probabilities without increasing severe adverse events despite high risk factors

Volumetric-modulated arc therapy vs conventional fixed-field intensity-modulated radiotherapy in a whole-ventricular irradiation: A planning comparison study.

This study evaluated the dosimetric difference between volumetric-modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (cIMRT) in whole-ventricular irradiation. Computed tomography simulation data for 13 patients were acquired to create plans for VMAT and cIMRT. In both plans, the same median dose (100% = 24Gy) was prescribed to the planning target volume (PTV), which comprised a tumor bed and whole ventricles. During optimization, doses to the normal brain and body were reduced, provided that the dose constraints of the target coverage were satisfied. The dose-volume indices of the PTV, normal brain, and body as well as monitor units were compared between the 2 techniques by using paired t-tests. The results showed no significant difference in the homogeneity index (0.064 vs 0.065; p = 0.824) of the PTV and conformation number (0.78 vs 0.77; p = 0.065) between the 2 techniques. In the normal brain and body, the dose-volume indices showed no significant difference between the 2 techniques, except for an increase in the volume receiving a low dose in VMAT; the absolute volume of the normal brain and body receiving 1Gy of radiation significantly increased in VMAT by 1.6% and 8.3%, respectively, compared with that in cIMRT (1044 vs 1028mL for the normal brain and 3079.2 vs 2823.3mL for the body; p<0.001). The number of monitor units to deliver a 2.0-Gy fraction was significantly reduced in VMAT compared with that in cIMRT (354 vs 873, respectively; p<0.001). In conclusion, VMAT delivers IMRT to complex target volumes such as whole ventricles with fewer monitor units, while maintaining target coverage and conformal isodose distribution comparable to cIMRT; however, in addition to those characteristics, the fact that the volume of the normal brain and body receiving a low dose would increase in VMAT should be considered