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1.
Cancer ; 126(2): 444-452, 2020 01 15.
Article in English | MEDLINE | ID: mdl-31593317

ABSTRACT

BACKGROUND: The role of radiotherapy (RT) in the treatment of patients with anaplastic thyroid cancer (ATC) for local tumor control is critical because mortality often is secondary to complications of tumor volume rather than metastatic disease. Herein, the authors report the long-term outcomes of RT for patients with ATC. METHODS: A total of 104 patients with histologically confirmed ATC were identified who presented to the study institution between 1984 and 2017 and who received curative-intent or postoperative RT. Locoregional progression-free survival (LPFS), overall survival (OS), and distant metastasis-free survival were assessed. RESULTS: The median age of the patients was 63.5 years. The median follow-up was 5.9 months (interquartile range, 2.7-17.0 months) for the entire cohort and 10.6 months (interquartile range, 5.3-40.0 months) for surviving patients. Thirty-one patients (29.8%) had metastatic disease prior to the initiation of RT. Concurrent chemoradiation was administered in 99 patients (95.2%) and 53 patients (51.0%) received trimodal therapy. Systemic therapy included doxorubicin (73.7%), paclitaxel with or without pazopanib (24.3%), and other systemic agents (2.0%). The 1-year OS and LPFS rates were 34.4% and 74.4%, respectively. On multivariate analysis, RT ≥60 Gy was associated with improved LPFS (hazard ratio [HR], 0.135; P = .001) and improved OS (HR, 0.487; P = .004), and trimodal therapy was associated with improved LPFS (HR, 0.060; P = .017). The most commonly observed acute grade 3 adverse events included dermatitis (20%) and mucositis (13%), with no grade 4 subacute or late adverse events noted (adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). CONCLUSIONS: RT appears to demonstrate a dose-dependent, persistent LPFS and OS benefit in patients with locally advanced ATC with an acceptable toxicity profile. Aggressive RT should be strongly considered for the treatment of patients with ATC as part of a trimodal treatment approach.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Radiotherapy, Intensity-Modulated/methods , Thyroid Carcinoma, Anaplastic/therapy , Thyroid Neoplasms/therapy , Thyroidectomy , Adult , Aged , Aged, 80 and over , Chemoradiotherapy, Adjuvant/adverse effects , Chemoradiotherapy, Adjuvant/methods , Dose-Response Relationship, Radiation , Doxorubicin/therapeutic use , Female , Follow-Up Studies , Humans , Indazoles , Male , Middle Aged , Paclitaxel/therapeutic use , Progression-Free Survival , Pyrimidines/therapeutic use , Radiotherapy Dosage , Radiotherapy, Intensity-Modulated/adverse effects , Retrospective Studies , Sulfonamides/therapeutic use , Thyroid Carcinoma, Anaplastic/mortality , Thyroid Carcinoma, Anaplastic/pathology , Thyroid Gland/pathology , Thyroid Gland/radiation effects , Thyroid Gland/surgery , Thyroid Neoplasms/mortality , Thyroid Neoplasms/pathology , Tumor Burden/radiation effects
2.
J Clin Oncol ; 42(8): 940-950, 2024 Mar 10.
Article in English | MEDLINE | ID: mdl-38241600

ABSTRACT

PURPOSE: Standard curative-intent chemoradiotherapy for human papillomavirus (HPV)-related oropharyngeal carcinoma results in significant toxicity. Since hypoxic tumors are radioresistant, we posited that the aerobic state of a tumor could identify patients eligible for de-escalation of chemoradiotherapy while maintaining treatment efficacy. METHODS: We enrolled patients with HPV-related oropharyngeal carcinoma to receive de-escalated definitive chemoradiotherapy in a phase II study (ClinicalTrials.gov identifier: NCT03323463). Patients first underwent surgical removal of disease at their primary site, but not of gross disease in the neck. A baseline 18F-fluoromisonidazole positron emission tomography scan was used to measure tumor hypoxia and was repeated 1-2 weeks intratreatment. Patients with nonhypoxic tumors received 30 Gy (3 weeks) with chemotherapy, whereas those with hypoxic tumors received standard chemoradiotherapy to 70 Gy (7 weeks). The primary objective was achieving a 2-year locoregional control (LRC) of 95% with a 7% noninferiority margin. RESULTS: One hundred fifty-eight patients with T0-2/N1-N2c were enrolled, of which 152 patients were eligible for analyses. Of these, 128 patients met criteria for 30 Gy and 24 patients received 70 Gy. The 2-year LRC was 94.7% (95% CI, 89.8 to 97.7), meeting our primary objective. With a median follow-up time of 38.3 (range, 22.1-58.4) months, the 2-year progression-free survival (PFS) and overall survival (OS) rates were 94% and 100%, respectively, for the 30-Gy cohort. The 70-Gy cohort had similar 2-year PFS and OS rates at 96% and 96%, respectively. Acute grade 3-4 adverse events were more common in 70 Gy versus 30 Gy (58.3% v 32%; P = .02). Late grade 3-4 adverse events only occurred in the 70-Gy cohort, in which 4.5% complained of late dysphagia. CONCLUSION: Tumor hypoxia is a promising approach to direct dosing of curative-intent chemoradiotherapy for HPV-related carcinomas with preserved efficacy and substantially reduced toxicity that requires further investigation.


Subject(s)
Carcinoma , Oropharyngeal Neoplasms , Papillomavirus Infections , Humans , Human Papillomavirus Viruses , Papillomavirus Infections/complications , Papillomavirus Infections/therapy , Oropharyngeal Neoplasms/therapy , Oropharyngeal Neoplasms/drug therapy , Chemoradiotherapy/adverse effects , Chemoradiotherapy/methods , Carcinoma/drug therapy , Hypoxia/etiology , Hypoxia/drug therapy
4.
JAMA Netw Open ; 6(1): e2250607, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36689229

ABSTRACT

Importance: Use of proton therapy reirradiation (PT-ReRT) for head and neck cancer is increasing; however, reports are heterogenous and outcomes can be difficult to interpret. Objective: To evaluate outcomes and toxic effects following PT-ReRT in a uniform and consecutive cohort of patients with head and neck squamous cell carcinoma. Design, Setting, and Participants: This retrospective cohort study included patients with recurrent primary head and neck squamous cell carcinoma who were treated with PT-ReRT from January 1, 2013, to December 31, 2020, at a single institution. Patient, clinical, and treatment characteristics were obtained, and multidisciplinary review was performed to record and grade early and late toxic effects. Exposures: Proton therapy reirradiation. Main Outcomes and Measures: Follow-up was defined from the start of PT-ReRT. The Kaplan-Meier method was used for outcomes of interest, including local control (LC), locoregional control, distant metastatic control, progression-free survival, and overall survival (OS). Cox proportional hazards regression modeling was used to assess associations of covariates with OS. Results: A total of 242 patients (median [range] age, 63 [21-96] years; 183 [75.6%] male) were included. Of these patients, 231 (95.9%) had a Karnofsky performance status score of 70 or higher, and 145 (59.9%) had at least a 10-pack-year smoking history. Median (range) follow-up was 12.0 (5.8-26.0) months for all patients and 24.5 (13.8-37.8) months for living patients. A total of 206 patients (85.1%) had recurrent disease vs second primary or residual disease. The median (range) interval between radiation courses was 22 (1-669) months. Median PT-ReRT dose was 70 cobalt gray equivalents (CGE) for the fractionated cohort and 44.4 CGE for the quad shot cohort. For the fractionated cohort, the 1-year LC was 71.8% (95% CI, 62.8%-79.0%) and the 1-year OS was 66.6% (95% CI, 58.1%-73.8%). For the quad shot cohort, the 1-year LC was 61.6% (95% CI, 46.4%-73.6%) and the 1-year OS was 28.5% (95% CI, 19.4%-38.3%). Higher Karnofsky performance status scores (hazard ratio [HR], 0.50; 95% CI, 0.25-0.99; P = .046) and receipt of salvage surgery prior to PT-ReRT (HR, 0.57; 95% CI, 0.39-0.84; P = .005) were associated with improved OS, whereas receipt of quad shot (HR, 1.97; 95% CI, 1.36-2.86; P < .001) was associated with worse OS. There were a total of 73 grade 3 and 6 grade 4 early toxic effects. There were 79 potential grade 3, 4 grade 4, and 5 grade 5 late toxic effects. Conclusions and Relevance: The findings of this cohort study suggest that, compared with previous reports with photon-based reirradiation, patients are living longer with aggressive PT-ReRT; however, surviving patients remain at risk of early and late complications.


Subject(s)
Head and Neck Neoplasms , Proton Therapy , Re-Irradiation , Humans , Male , Middle Aged , Female , Squamous Cell Carcinoma of Head and Neck , Re-Irradiation/adverse effects , Re-Irradiation/methods , Cohort Studies , Proton Therapy/adverse effects , Retrospective Studies , Neoplasm Recurrence, Local
5.
JAMA Oncol ; 8(3): 364-372, 2022 Mar 01.
Article in English | MEDLINE | ID: mdl-35050342

ABSTRACT

IMPORTANCE: Several de-escalation strategies for human papillomavirus (HPV)-associated oropharyngeal carcinoma (OPC) have focused on deintensifying gross disease treatment. Reduction of radiotherapy dose and target volume to subclinical regions may achieve good clinical outcomes with favorable patient quality of life (QOL). OBJECTIVE: To determine outcomes from a systematic approach of reducing radiotherapy dose and target volume to the elective treatment regions in patients with HPV-associated OPC undergoing concurrent chemoradiotherapy (CCRT). DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included 276 consecutive patients with HPV-positive OPC receiving CCRT from March 1, 2017, to July 31, 2019. Data were analyzed from February 23 to September 13, 2021. INTERVENTIONS: Elective nodal and subclinical regions received 30 Gy of radiotherapy in 15 fractions, followed by a cone down of 40 Gy in 20 fractions to gross disease for a total dose of 70 Gy. The high retropharyngeal nodal basins in the node-negative neck and bilateral levels IB and V basins were omitted. MAIN OUTCOMES AND MEASURES: Patients were followed up to evaluate locoregional control as the primary outcome and distant metastasis-free survival, progression-free survival, and overall survival as secondary outcomes. Quality-of-life data were obtained at each visit when feasible. RESULTS: Among the 276 patients included in the analysis, the median age was 61 (range, 36-87) years; 247 (89.5%) were men; and 183 (66.3%) had less than 10 pack-years of smoking history. Most patients (251 [90.9%]) were White. Overall, 87 (31.5%) had cT3-cT4 disease and 65 (23.5%) had cN2-cN3 disease per the 8th edition of the American Joint Committee on Cancer Staging Manual. One hundred seventy-two patients (62.3%) completed 300-mg/m2 high-dose cisplatin therapy. During a median follow-up of 26 (range, 21-32) months, 8 patients developed locoregional recurrence, including 7 at the primary site or gross nodes that received a total dose of 70 Gy and 1 with a persistent node not previously identified as gross disease that received a total dose of only 30 Gy. The 24-month locoregional control was 97.0%; progression-free survival, 88.0%; distant metastasis-free survival, 95.2%; and overall survival, 95.1%. During treatment, 17 patients (6.2%) required a feeding tube. At 24 months, most of the QOL composite scores (jaw-related problems, pain, social contact, eating, speech, and swallow) were comparable or superior to baseline measures except for senses, dry mouth, muscular tension, and cognitive functioning, which improved over time but remained marginally worse than baseline. CONCLUSIONS AND RELEVANCE: This cohort study found that the evaluated de-escalation strategy for elective regions showed favorable clinical outcomes and QOL profiles. Long-term follow-up data will help affirm the efficacy of this strategy as a care option for treating HPV-associated OPC with primary CCRT.


Subject(s)
Alphapapillomavirus , Carcinoma , Oropharyngeal Neoplasms , Papillomavirus Infections , Adult , Aged , Aged, 80 and over , Carcinoma/drug therapy , Chemoradiotherapy/adverse effects , Cohort Studies , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Oropharyngeal Neoplasms/complications , Oropharyngeal Neoplasms/pathology , Oropharyngeal Neoplasms/therapy , Oropharyngeal Neoplasms/virology , Papillomaviridae , Quality of Life , Retrospective Studies
6.
Cancer Med ; 10(13): 4221-4227, 2021 07.
Article in English | MEDLINE | ID: mdl-34085781

ABSTRACT

Patients with previously treated, recurrent or metastatic sarcomas who have progressed on multiples lines of systemic therapy may have limited options for local control. We evaluated outcomes of palliative proton therapy with the quad shot regimen to unresectable disease for patients with recurrent and/or metastatic sarcoma. From 2014 to 2018, 28 patients with recurrent or metastatic sarcomas were treated to 40 total sites with palliative proton RT with quad shot (14.8 Gy/4 twice daily). Outcomes included toxicity, ability to receive further systemic therapy, and subjective palliative response. Univariate analysis was performed for local progression-free survival (LPFS) and overall survival (OS). Of the 40 total sites, 25 (62.5%) received ≥3 cycles with median follow up of 12 months (IQR 4-19). The most common histologies were GIST (9; 22.5%) and leiomyosarcoma (7; 17.5%). A total of 27 (67.5%) sites were located in the abdomen or pelvis. Seventeen (42.5%) treatments involved concurrent systemic therapy and 13 (32.5%) patients received further systemic therapy following proton therapy. Overall subjective palliative response was 70%. Median LPFS was 11 months and 6-month LPFS was 66.1%. On univariate analysis, receipt of four cycles of quad shot (HR 0.06, p = 0.02) and receipt of systemic therapy after completion of radiation therapy (HR 0.17, p = 0.02) were associated with improved LPFS. Three grade 3 acute toxicities were observed. The proton quad shot regimen serves as a feasible alternative for patients with previously treated, recurrent or metastatic sarcomas where overall treatment options may be limited.


Subject(s)
Neoplasm Recurrence, Local/radiotherapy , Proton Therapy/methods , Sarcoma/radiotherapy , Abdominal Neoplasms/radiotherapy , Adult , Aged , Female , Humans , Leiomyosarcoma/mortality , Leiomyosarcoma/pathology , Leiomyosarcoma/radiotherapy , Leiomyosarcoma/secondary , Male , Middle Aged , Neoplasm Recurrence, Local/mortality , Palliative Care/methods , Pelvic Neoplasms/radiotherapy , Progression-Free Survival , Response Evaluation Criteria in Solid Tumors , Retrospective Studies , Sarcoma/mortality , Sarcoma/pathology , Sarcoma/secondary
7.
Oral Oncol ; 104: 104641, 2020 05.
Article in English | MEDLINE | ID: mdl-32182548

ABSTRACT

OBJECTIVES: Patients with prior irradiated head and neck cancer (HNC) who are ineligible for definitive retreatment have limited local palliative options. We report the largest series of the use of the Quad Shot (QS) regimen as a last-line local palliative therapy. MATERIALS AND METHODS: We identified 166 patients with prior HN radiation therapy (RT) treated with QS regimen (3.7 Gy twice daily over 2 consecutive days at 4 weeks intervals per cycle, up to 4 cycles). Palliative response defined by symptom(s) relief or radiographic tumor reduction, locoregional progression free survival (LPFS), overall survival (OS) and radiation-related toxicity were assessed. RESULTS: Median age was 66 years. Median follow-up for all patients was 6.0 months and 9.7 months for living patients. Overall palliative response rate was 66% and symptoms improved in 60% of all patients. Predictors of palliative response were > 2 year interval from prior RT and 3-4 QS cycles. Median LPFS was 5.1 months with 1-year LPFS 17.7%, and median OS was 6.4 months with 1-year OS 25.3%. On multivariate analysis, proton RT, KPS > 70, presence of palliative response and 3-4 QS cycles were associated with improved LPFS and improved OS. The overall Grade 3 toxicity rate was 10.8% (n = 18). No Grade 4-5 toxicities were observed. CONCLUSION: Palliative QS is an effective last-line local therapy with minimal toxicity in patients with previously irradiated HNC. The administration of 3-4 QS cycles predicts palliative response, improved PFS, and improved OS. KPS > 70 and proton therapy are associated with survival improvements.


Subject(s)
Head and Neck Neoplasms/drug therapy , Proton Therapy/methods , Aged , Female , Head and Neck Neoplasms/mortality , Humans , Male , Survival Analysis
8.
Head Neck ; 41(10): 3551-3563, 2019 10.
Article in English | MEDLINE | ID: mdl-31294897

ABSTRACT

BACKGROUND: Timely postoperative radiation therapy (RT) within 50 days of surgery for head and neck cancers provides a survival advantage. METHODS: Using the National Cancer Database, we performed a propensity score-matched analysis comparing patients undergoing open or endoscopic surgery for squamous cell carcinoma (SCC) of the nasal cavity and paranasal sinuses from 2010 to 2015. RESULTS: Among 168 pairs, patients undergoing endoscopic surgery had shorter time to surgery (24.2 vs 36.7 days, P < .001) and shorter postoperative time to RT (PTTR, 51.2 vs 58.4 days, P = .02). On multivariable linear regression, endoscopic surgery predicted shorter PTTR (ß = -7.6, P = .01). Using the Kaplan-Meier method, patients in the longest PTTR quartile had decreased overall survival (OS; Q1 vs Q4, 3-year OS 76.5% vs 53.3%, P = .007), a durable finding when adjusted for covariates (Q1 vs Q4, HR 0.50, P = .008). CONCLUSIONS: Patients undergoing endoscopic surgery for sinonasal SCC experience shorter PTTR. Shorter PTTR is associated with extended OS.


Subject(s)
Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/surgery , Endoscopy/methods , Paranasal Sinus Neoplasms/mortality , Paranasal Sinus Neoplasms/surgery , Adult , Aged , Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/radiotherapy , Combined Modality Therapy , Databases, Factual , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Linear Models , Male , Middle Aged , Otorhinolaryngologic Surgical Procedures/methods , Paranasal Sinus Neoplasms/pathology , Paranasal Sinus Neoplasms/radiotherapy , Propensity Score , Radiotherapy, Adjuvant , Retrospective Studies , Risk Assessment , Survival Analysis , Time Factors
9.
Am J Clin Oncol ; 41(2): 107-114, 2018 Feb.
Article in English | MEDLINE | ID: mdl-26535994

ABSTRACT

OBJECTIVES: To report our institutional experience using definitive chemoradiation via whole bladder (WB) and partial bladder (PB) treatment in muscle-invasive bladder cancer. Combining intensity-modulated radiation therapy with image-guidance can improve the therapeutic ratio. MATERIALS AND METHODS: Retrospective analysis of 26 patients with clinical stage T2-4 N0-2 M0 urothelial cancer treated in 2009 to 2012; 16 received WB radiation and 10 received PB radiation. PB/tumor boost volume included visibly thickened bladder wall or tumor localized on cystoscopy. WB radiation delivered 45 to 50.4 Gy to bladder/lymph nodes, then sequential 19.8 to 21.6 Gy tumor boost (1.8 Gy/fx). PB radiation was 45 to 50 Gy to lymph nodes (1.8 to 2 Gy/fx) and simultaneous integrated boost to 55 to 62.5 Gy to tumor only (2.2 to 2.5 Gy/fx). The primary endpoint was local control, defined as no muscle-invasive recurrence. Secondary endpoints were overall survival, toxicity, and cost. RESULTS: Mean age was 77 and median follow-up was 20 months. Freedom from local recurrence was 86% at 2 years (PB 100%, WB 77%). Overall survival was 80% at 1 year (PB 88%, WB 75%), and 55% at 2 years (PB 70%, WB 48%, P=0.38). Failure was predominantly distant. Toxicities were minimal (3 late grade 3 ureteral, 1 acute grade 4 renal), and all resolved. No cystectomies were performed for toxicity. Hypofractionation reduces treatment time and costs by one third. CONCLUSIONS: Image-guided hypofractionated PB radiation provides local control with similar survival to WB therapy, with minimal toxicity. Hypofractionation also offers time and cost advantages. Our results need to be validated in a larger, multi-institutional cohort.


Subject(s)
Organ Sparing Treatments/methods , Radiotherapy, Image-Guided , Radiotherapy, Intensity-Modulated/methods , Urinary Bladder Neoplasms/pathology , Urinary Bladder Neoplasms/radiotherapy , Aged , Aged, 80 and over , Carcinoma, Transitional Cell/mortality , Carcinoma, Transitional Cell/pathology , Carcinoma, Transitional Cell/radiotherapy , Cohort Studies , Disease-Free Survival , Female , Geriatric Assessment , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Neoplasm Invasiveness/pathology , Neoplasm Staging , Prognosis , Radiation Dose Hypofractionation , Radiation Injuries/prevention & control , Radiotherapy, Intensity-Modulated/adverse effects , Retrospective Studies , Risk Assessment , Survival Analysis , Treatment Outcome , United States , Urinary Bladder Neoplasms/mortality
10.
Am J Clin Oncol ; 41(1): 1-5, 2018 Jan.
Article in English | MEDLINE | ID: mdl-26237192

ABSTRACT

OBJECTIVES: To examine the impact of positive surgical margin (PSM) laterality on failure after radical prostatectomy (RP). A PSM can influence local recurrence and outcomes after salvage radiation. Unlike intrinsic risk factors, a PSM is caused by intervention and thus iatrogenic failures may be elucidated by analyzing margin laterality as surgical approach is itself lateralized. PATIENTS AND METHODS: We reviewed 226 RP patients between 1991 and 2013 with PSM. Data includes operation type, pre/postoperative PSA, surgical pathology, and margin type (location, focality, laterality). The median follow-up was 47 months. Biochemical recurrence after RP was defined as PSA≥0.1 ng/mL or 2 consecutive rises above nadir. Ninety-two patients received salvage radiation therapy (SRT). Failure after SRT was defined as any PSA≥0.2 ng/mL or greater than presalvage. Kaplan-Meier and Cox multivariate analyses compared relapse rates. RESULTS: The majority of PSM were iatrogenic (58%). Laterality was associated with differences in median relapse: right 20 versus left 51 versus bilateral 14 months (P<0.01). Preoperative PSA, T-stage, Gleason grade, and laterality were associated with biochemical progression on univariate and multivariate analyses. Right-sided margins were more likely to progress than left (hazard ratio, 1.67; P=0.04). More right-sided margins were referred for SRT (55% right vs. 23% left vs. 22% bilateral), but were equally salvaged. Only T-stage and pre-SRT PSA independently influenced SRT success. CONCLUSIONS: Most PSM are iatrogenic, with right-sided more likely to progress (and sooner) than left sided. Margin laterality is a heretofore unrecognized independent predictor of biochemical relapse and hints at the need to modify the traditional unilateral surgical technique.


Subject(s)
Margins of Excision , Neoplasm Recurrence, Local/mortality , Prostate-Specific Antigen/blood , Prostatectomy/methods , Prostatic Neoplasms/mortality , Prostatic Neoplasms/surgery , Aged , Analysis of Variance , Cohort Studies , Databases, Factual , Disease-Free Survival , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Neoplasm Grading , Neoplasm Recurrence, Local/blood , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/radiotherapy , Proportional Hazards Models , Prostatectomy/adverse effects , Prostatic Neoplasms/pathology , Retrospective Studies , Risk Assessment , Salvage Therapy/methods , Survival Analysis , Treatment Outcome
11.
Int J Radiat Oncol Biol Phys ; 91(4): 832-9, 2015 Mar 15.
Article in English | MEDLINE | ID: mdl-25752398

ABSTRACT

PURPOSE: To determine whether image guidance with rigid registration (RR) to intraprostatic markers (IPMs) yields acceptable coverage of the pelvic lymph nodes in the context of a stereotactic body radiation therapy (SBRT) regimen. METHODS AND MATERIALS: Four to seven kilovoltage cone-beam CTs (CBCTs) from 12 patients with high-risk prostate cancer were analyzed, allowing approximation of an SBRT regimen. The nodal clinical target volume (CTV(N)) and bladder were contoured on all kilovoltage CBCTs. The V100 CTV(N), expressed as a ratio to the same parameter on the initial plan, and the magnitude of translational shift between RR to the IPMs versus RR to the pelvic bones, were computed. The ability of a multimodality bladder filling protocol to minimize bladder height variation was assessed in a separate cohort of 4 patients. RESULTS: Sixty-five CBCTs were assessed. The average V100 CTV(N) was 92.6%, but for a subset of 3 patients the average was 80.0%, compared with 97.8% for the others (P<.0001). The average overall and superior-inferior axis magnitudes of the bony-to-fiducial translations were significantly larger in the subgroup with suboptimal nodal coverage (8.1 vs 3.9 mm and 5.8 vs 2.4 mm, respectively; P<.0001). Relative bladder height changes were also significantly larger in the subgroup with suboptimal nodal coverage (42.9% vs 18.5%; P<.05). Use of a multimodality bladder-filling protocol minimized bladder height variation (P<.001). CONCLUSION: A majority of patients had acceptable nodal coverage after RR to IPMs, even when approximating SBRT. However, a subset of patients had suboptimal nodal coverage. These patients had large bony-to-fiducial translations and large variations in bladder height. Nodal coverage should be excellent if the superior-inferior axis bony-to-fiducial translation and the relative bladder height change (both easily measured on CBCT) are kept to a minimum. Implementation of a strict bladder filling protocol may achieve this goal.


Subject(s)
Cone-Beam Computed Tomography/methods , Prostatic Neoplasms/surgery , Radiosurgery , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Image-Guided/methods , Anatomic Landmarks/diagnostic imaging , Fiducial Markers , Humans , Lymph Nodes/diagnostic imaging , Lymphatic Irradiation , Male , Movement , Organ Size , Pelvic Bones/diagnostic imaging , Pelvis , Prostate/diagnostic imaging , Prostatic Neoplasms/diagnostic imaging , Radiotherapy Dosage , Rectum/anatomy & histology , Rectum/diagnostic imaging , Seminal Vesicles , Urinary Bladder/anatomy & histology , Urinary Bladder/diagnostic imaging
12.
Hypertension ; 51(6): 1597-604, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18413493

ABSTRACT

In addition to the juxtaglomerular apparatus, renin is also synthesized in renal tubular epithelium, including the collecting duct (CD). Angiotensin (Ang) II differentially regulates the synthesis of juxtaglomerular (inhibition) and CD (stimulation) renin. Because diabetes mellitus, a disease with high intrarenal renin-Ang system and Ang II activity, is characterized by high prorenin levels, we hypothesized that the CD is the major source of prorenin in diabetes. Renin granular content was visualized using in vivo multiphoton microscopy of the kidney in diabetic Munich-Wistar rats. Diabetes caused a 3.5-fold increase in CD renin, in contrast to less pronounced juxtaglomerular changes. Ang II type 1 receptor blockade with Olmesartan reduced CD renin to control levels but significantly increased juxtaglomerular renin. Using a fluorogenic renin assay, the prorenin component of CD renin content was measured by assessing the difference in enzymatic activity of medullary homogenates before and after trypsin activation of prorenin. Trypsinization caused no change in control renin activity but a 5-fold increase in diabetes. Studies on a CD cell line (M1) showed a 22-fold increase in renin activity after trypsinization and a further 35-fold increase with Ang II treatment. Therefore, prorenin significantly contributes to baseline CD renin. Diabetes, possibly via Ang II, greatly stimulates CD prorenin and causes hyperplasia of renin-producing connecting segments. These novel findings suggest that, in a rat model of diabetes, prorenin content and release from the CD may be more important than the juxtaglomerular apparatus in contrast to the existing paradigm.


Subject(s)
Diabetic Nephropathies/metabolism , Hypertension, Renal/metabolism , Juxtaglomerular Apparatus/metabolism , Kidney Tubules, Collecting/metabolism , Renin/metabolism , Angiotensin II/metabolism , Angiotensin II/pharmacology , Angiotensin II Type 1 Receptor Blockers/pharmacology , Animals , Cell Division/physiology , Cells, Cultured , Diabetes Mellitus, Experimental/metabolism , Disease Models, Animal , Imidazoles/pharmacology , Immunohistochemistry , Juxtaglomerular Apparatus/cytology , Kidney Tubules, Collecting/cytology , Microscopy, Fluorescence , Quinacrine , Rats , Rats, Wistar , Tetrazoles/pharmacology , Trypsin , Vasoconstrictor Agents/metabolism , Vasoconstrictor Agents/pharmacology
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