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Storm KS, Spindler KLG, Persson GF, Kronborg C, Serup-Hansen E. Lower urinary tract sub-structures as predictors of late urinary toxicity in concurrent chemo-radiotherapy for anal cancer. Radiother Oncol 2025; 204:110708. [PMID: 39761919 DOI: 10.1016/j.radonc.2025.110708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2024] [Revised: 12/17/2024] [Accepted: 12/26/2024] [Indexed: 01/14/2025]
Abstract
BACKGROUND AND PURPOSE Late toxicity is substantial after chemotherapy for anal cancer. This study aimed to investigate the relationship between radiation dose to lower urinary tract sub-structures and the risk of late urinary toxicities, in patients with anal cancer treated with chemoradiotherapy or radiotherapy. MATERIALS AND METHODS From 2015 to 2021, 314 patients with localized anal cancer were included in a national prospective registration study. Urinary toxicity (CTCAE) was scored during treatment (acute toxicity) and at one- and three-years follow-up (late toxicity). Lower urinary tract sub-structures (bladder, bladder neck, bladder trigone, and urethra) were contoured post-hoc on the planning-CT and dosimetric variables extracted. Logistic regression was used to evaluate the association between clinical and dosimetric variables and registered toxicity. RESULTS There was an increase in late toxicity from baseline of 15 % for both urgency and frequency, and 25 % for incontinence. The most common late toxicity was urinary frequency, with 40 % of patients experiencing grade 1 and 2 % experiencing grade 2 toxicity. A dose-effect relationship was found for late urinary urgency and increasing D0.1 cm3 of the urethra (p = 0.01). Increased late urinary frequency was correlated to increasing D2cm3 of the urethra (p = 0.007), and bladder neck V30Gy (p = 0.03). Patients with acute toxicity had up to three times increased risk of corresponding late toxicity. CONCLUSION We found a significant dose-effect relationship between radiation dose to urethra and bladder neck and late urinary toxicity. These findings warrant more focus on these structures when optimizing radiotherapy for anal cancer. Furthermore, a strong association between having acute toxicity and developing late toxicity was shown.
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Affiliation(s)
- Katrine S Storm
- Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Karen Lise G Spindler
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Gitte F Persson
- Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Kronborg
- Danish Centre for Particle Therapy, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Eva Serup-Hansen
- Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark
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2
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Lee G, Nelson B, Koenig J, Plastaras JP, Metz JM, Yeap BY, Zhang Y, Drapek LC, Baglini C, Ryan DP, Parikh AR, Allen JN, Clark JW, Blaszkowsky LS, Ben-Josef E, Hong TS, Kharofa JR, Wo JY. Long-term Outcomes of Definitive Chemoradiation With Proton Therapy for Treatment of Carcinoma of the Anal Canal: Combined Analysis of 2 Prospective Trials. Int J Radiat Oncol Biol Phys 2025:S0360-3016(25)00015-X. [PMID: 39800328 DOI: 10.1016/j.ijrobp.2024.12.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2024] [Revised: 11/22/2024] [Accepted: 12/25/2024] [Indexed: 01/18/2025]
Abstract
PURPOSE Although definitive chemoradiation therapy (CRT) with 5-fluorouracil (5-FU) and mitomycin-C (MMC) (5-FU/MMC) remains the standard of care for localized anal cancer, treatment is associated with significant acute and late toxicity. Proton radiation therapy (RT) may potentially reduce such toxicity. Here, we assess the long-term outcomes of patients with anal cancer treated with CRT using proton RT in 2 prospective pilot studies. METHODS AND MATERIALS Patients with stage I to III anal cancer treated with proton RT (pencil beam scanning or intensity modulated proton therapy) per Radiation Therapy Oncology Group (RTOG) 0529 dose schema with concurrent 5-FU/MMC (2 cycles) in 2 prospective, single-arm trials were followed. Locoregional failure, distant metastases, colostomy-free survival, disease-free survival, and overall survival were assessed. Physician-graded late toxicity (>90 days from CRT) was assessed per National Cancer Institute Common Terminology Criteria for Adverse Events version 4. Late toxicities were compared with RTOG 0529 via Fisher exact test. Patient-reported outcomes were analyzed. RESULTS Between 2013 and 2020, 39 patients were treated; 37 (95%) patients completed treatment per protocol. The median follow-up was 63 months. The 5-year locoregional failure, distant metastases, colostomy-free survival, disease-free survival, and overall survival were 21%, 19%, 72%, 69%, and 75%, respectively. The worst late treatment toxicities were grade 1 in 38%, grade 2 in 24%, grade 3 in 19%, grade 4 in 3%, and no grade 5. Compared to RTOG 0529, rates of overall grade 2+ late toxicities were significantly lower (46% vs 75%, P = .01), attributed to lower dermatologic toxicities (0% vs 25%, P < .01), but there was no significant difference in overall grade 3+ toxicities (22% vs 20%, P = 1.00). No statistically significant correlations between organ-at-risk dosimetry and late toxicities were noted. Available patient-reported outcomes demonstrated that significant proportion of patients had persistent gastrointestinal symptoms at long term. CONCLUSIONS Definitive CRT with proton RT with concurrent 5-FU/MMC for the treatment of anal cancer resulted in comparable long-term disease control and grade 3+ late toxicities compared to RTOG 0529. Future studies should evaluate additional measures to minimize treatment toxicity and subsets of patients who are most likely to benefit from proton RT.
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Affiliation(s)
- Grace Lee
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Bailey Nelson
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, Ohio
| | - Julie Koenig
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - John P Plastaras
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - James M Metz
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Beow Y Yeap
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yongbin Zhang
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, Ohio
| | - Lorraine C Drapek
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Christian Baglini
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - David P Ryan
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Aparna R Parikh
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jill N Allen
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jeffrey W Clark
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Lawrence S Blaszkowsky
- Division of Medical Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Edgar Ben-Josef
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Theodore S Hong
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jordan R Kharofa
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, Ohio.
| | - Jennifer Y Wo
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
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3
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Jirkovská M, Stankušová H, Kindlová A, Jirkovský D, Lohynská R. Interstitial HDR brachytherapy for anal cancer-results and quality of life. Strahlenther Onkol 2024:10.1007/s00066-024-02316-5. [PMID: 39542884 DOI: 10.1007/s00066-024-02316-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 10/02/2024] [Indexed: 11/17/2024]
Abstract
PURPOSE While anal cancer is a very rare oncological diagnosis representing less than 2% of lower gastrointestinal tract cancers, the incidence has doubled in the past 20 years. Radical radiochemotherapy with sequential or simultaneous boost is now the standard treatment modality. Interstitial HDR brachytherapy is one of the boost application options. Implementation of new radiotherapy techniques has resulted in improved therapeutic outcomes; however, it is still associated with acute and especially late toxicity. Gastrointestinal disorders and sexual dysfunction are the most frequent factors affecting the long-term quality of cured patients' lives. METHODS A total of 96 patients consecutively treated between 2000 and 2022 with external beam radio-/chemotherapy and an interstitial brachytherapy boost for histologically verified nonmetastatic anal squamous cell carcinoma were evaluated. The median follow-up time was 15.4 years (range 13.4-17.3 years). The primary objective of the study was to assess local control (LC) and quality of life (QoL). The Czech versions of internationally validated EORTC questionnaires were used to evaluate life quality-the basic EORTC QOL-C30 v.3 and the specific QOL-ANL 27 questionnaire. RESULTS Local control was 85.5% at 5 years, 83.4% at 10 years, 83.4% at 15 years, and 83.4% at 20 years, and there was no dependence on clinical stage. The most common forms of acute toxicity were cutaneous and hematological but were gastrointestinal for late toxicities. In the evaluation of quality of life, 80.5% of patients alive at the time participated. In the EORTC quality of life questionnaire C30 v.3, patients rated the functional scale score as 86.2 points (standard deviation [SD] = 12.6) and the symptom score as 15.5 points (SD = 12.5). The global health score achieved 68.4 points (SD = 23.6). The most common symptoms were fatigue with 25.6 points (SD = 20.2) and diarrhea with 19.0 points (SD = 27.8). In the QOL-ANL 27 questionnaire, symptom scales assessing bowel symptoms were scored 27.5 points (SD = 19) in non-stoma patients and 11.9 points (SD = 17.2) in stoma patients. In the single-item symptom scales, the highest scores were rated for frequency of urination with 26.4 points (SD = 30.8), need to be close to a toilet with 22.4 points (SD = 27.3), and self-cleaning more often with 25.3 points (SD = 31.8). In the functional scales assessing sex life and interest, men and women reported scores of 45.2 (SD = 23) and 45.5 points (SD = 19), respectively. CONCLUSION Boost with interstitial HDR brachytherapy is an established safe method of anal cancer treatment, with excellent results and limited late toxicity. Functioning scales were rated relatively highly in QoL questionnaires, and the overall global health score was comparable to published data. Gastrointestinal difficulties, fatigue, and sexual dysfunction dominated the symptom scales in our cohort.
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Affiliation(s)
- Michaela Jirkovská
- Department of Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Úvalu 84, 150 06, Prague, Czech Republic.
| | - Hana Stankušová
- Department of Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Anna Kindlová
- Department of Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Daniel Jirkovský
- Second Faculty of Medicine, Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Radka Lohynská
- Department of Oncology, First Faculty of Medicine, Charles University and Thomayer University Hospital in Prague, Vídeňská 800, 140 59, Prague, Czech Republic
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4
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Axelsson A, Johansson M, Haglind E, Li Y, Nilsson PJ, Angenete E. Patient reported long-term side effects from treatment on urinary and sexual function in anal cancer survivors - 3- and 6-year results from the Swedish national ANCA study. Colorectal Dis 2024; 26:1359-1369. [PMID: 38816903 DOI: 10.1111/codi.17040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/19/2024] [Accepted: 05/05/2024] [Indexed: 06/01/2024]
Abstract
AIM The standard treatment for anal cancer is chemoradiotherapy. Most patients survive anal cancer but remain living with long-term side effects related to the treatment received. The aim of this study was to assess the occurrence of long-term impairment of urinary and sexual function at 3 and 6 years after diagnosis and to investigate the additive effect from chemotherapy in combined chemoradiotherapy on urinary incontinence, compared to radiotherapy alone. METHOD The ANal CAncer study (ANCA) is based on a national Swedish cohort of patients diagnosed with anal cancer between 2011 and 2013. All identified patients within the study were invited to respond to a study-specific questionnaire at 3 and 6 years. Descriptive analyses for the primary endpoint were performed. To investigate a possible additional effect from chemotherapy logistic regression was used. RESULTS A total of 388 patients were included in the study. At 3 years 264 patients were alive and invited to respond to an anal cancer specific questionnaire. The 3- and 6 year response rates were 195 (74%) and 155 patients (67%), respectively. The patient reported urinary function impairment at 3 years were urgency (63%), incomplete bladder emptying (47%), and incontinence (46%) and there was an absolute increase of the prevalence of urinary dysfunction in about 10% at 6 years. Three years after diagnosis, 77% reported that intercourse was not part of their sex life; this percentage increased at 6 years to 83%. We found no negative effect of chemotherapy in combined chemoradiotherapy versus radiotherapy alone on patient reported urinary incontinence. CONCLUSION For anal cancer survivors, urinary function was impaired after 3 years and continued to deteriorate as measured at 6 years after diagnosis. Anal cancer and its treatment negatively affected sexual function for both men and women. This may explain why patients reported that sexual activity and frequency of intercourse was not of importance in their life.
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Affiliation(s)
- Anna Axelsson
- Department of Surgery, SSORG-Scandinavian Surgical Outcomes Research Group, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Oncology, Sahlgrenska University Hospital/Sahlgrenska, Gothenburg, Sweden
| | - Mia Johansson
- Department of Oncology, Sahlgrenska University Hospital/Sahlgrenska, Gothenburg, Sweden
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Eva Haglind
- Department of Surgery, SSORG-Scandinavian Surgical Outcomes Research Group, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Surgery, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden
| | - Ying Li
- Department of Surgery, SSORG-Scandinavian Surgical Outcomes Research Group, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Per J Nilsson
- Division of Coloproctology, Department of Pelvic Center, Karolinska University Hospital, Stockholm, Sweden
| | - Eva Angenete
- Department of Surgery, SSORG-Scandinavian Surgical Outcomes Research Group, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Surgery, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden
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5
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Dickstein DR, Edwards CR, Rowan CR, Avanessian B, Chubak BM, Wheldon CW, Simoes PK, Buckstein MH, Keefer LA, Safer JD, Sigel K, Goodman KA, Rosser BRS, Goldstone SE, Wong SY, Marshall DC. Pleasurable and problematic receptive anal intercourse and diseases of the colon, rectum and anus. Nat Rev Gastroenterol Hepatol 2024; 21:377-405. [PMID: 38763974 DOI: 10.1038/s41575-024-00932-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/12/2024] [Indexed: 05/21/2024]
Abstract
The ability to experience pleasurable sexual activity is important for human health. Receptive anal intercourse (RAI) is a common, though frequently stigmatized, pleasurable sexual activity. Little is known about how diseases of the colon, rectum, and anus and their treatments affect RAI. Engaging in RAI with gastrointestinal disease can be difficult due to the unpredictability of symptoms and treatment-related toxic effects. Patients might experience sphincter hypertonicity, gastrointestinal symptom-specific anxiety, altered pelvic blood flow from structural disorders, decreased sensation from cancer-directed therapies or body image issues from stoma creation. These can result in problematic RAI - encompassing anodyspareunia (painful RAI), arousal dysfunction, orgasm dysfunction and decreased sexual desire. Therapeutic strategies for problematic RAI in patients living with gastrointestinal diseases and/or treatment-related dysfunction include pelvic floor muscle strengthening and stretching, psychological interventions, and restorative devices. Providing health-care professionals with a framework to discuss pleasurable RAI and diagnose problematic RAI can help improve patient outcomes. Normalizing RAI, affirming pleasure from RAI and acknowledging that the gastrointestinal system is involved in sexual pleasure, sexual function and sexual health will help transform the scientific paradigm of sexual health to one that is more just and equitable.
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Affiliation(s)
- Daniel R Dickstein
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Collin R Edwards
- Department of Radiology, Vagelos College of Physicians and Surgeons of Columbia University, New York, NY, USA
| | - Catherine R Rowan
- Inflammatory Bowel Disease Unit, Division of Gastroenterology and Hepatology, University of Calgary, Calgary, Alberta, Canada
| | - Bella Avanessian
- Center for Transgender Medicine and Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Division of Plastic and Reconstructive Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Barbara M Chubak
- Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Christopher W Wheldon
- Department of Social and Behavioral Sciences, College of Public Health at Temple University, Philadelphia, PA, USA
| | - Priya K Simoes
- The Dr. Henry D. Janowitz Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michael H Buckstein
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Laurie A Keefer
- The Dr. Henry D. Janowitz Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Joshua D Safer
- Center for Transgender Medicine and Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Division of Endocrinology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Keith Sigel
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Karyn A Goodman
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - B R Simon Rosser
- Division of Epidemiology and Community Health, School of Public Health at University of Minnesota, Minneapolis, MN, USA
| | - Stephen E Goldstone
- Department of Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Serre-Yu Wong
- The Dr. Henry D. Janowitz Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Deborah C Marshall
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Arzola A, Chang E, Rooney MK, Corrigan K, Das P, Ludmir EB, Koay EJ, Minsky BD, Smith GL, Messick C, Morris VK, Nebgen D, Crane CH, Holliday EB. Daily Vaginal Dilator Use During Radiation for Women With Squamous Cell Carcinoma of the Anus: Vaginal Wall Dosimetry and Patient-Reported Sexual Function. Pract Radiat Oncol 2024; 14:e105-e116. [PMID: 37898354 DOI: 10.1016/j.prro.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/19/2023] [Accepted: 10/12/2023] [Indexed: 10/30/2023]
Abstract
PURPOSE At our institution, we treat patients with a daily vaginal dilator (VD) during chemoradiation (CRT) for squamous cell carcinoma of the anus (SCCA). We evaluated compliance with daily VD use, radiation dose to the vaginal wall (VW), and anterior vaginal wall (AVW), and patient-reported long-term sexual function. METHODS AND MATERIALS We included women with SCCA who received definitive, intensity-modulated radiation therapy-based CRT. Women who were alive without evidence of disease received a patient-reported outcome survey, which included the Female Sexual Function Index (FSFI). We identified factors associated with FSFI, such as radiation dose to the VW and AVW using linear regression models and used Youden index analysis to estimate a dose cutoff to predict sexual dysfunction. RESULTS Three hundred thirty-nine consecutively treated women were included in the analysis; 285 (84.1%) were treated with a daily VD. Of 184 women alive without disease, 90 patients (49%) completed the FSFI, and 51 (56.7%) were sexually active with valid FSFI scores. All received therapy with a daily VD. Forty-one women (80%) had sexual dysfunction. Univariate analysis showed higher dose to 50% (D50%) of the AVW correlated with worse FSFI (β -.262; P = .043), worse desire FSFI subscore (β -.056; P = .003), and worse pain FSFI subscore (β -.084; P = .009). Younger age correlated with worse pain FSFI subscale (β .067; P = .026). Age (β .070; P = .013) and AVW D50% (β -.087; P = .009) were significant on multivariable analysis. AVW D50% >48 Gy predicted increased risk of sexual dysfunction. CONCLUSIONS Daily VD use is safe and well tolerated during CRT for SCCA. Using a VD during treatment to displace the AVW may reduce the risk for sexual dysfunction. Limiting the AVW D50% <48 Gy may further reduce the risk but additional data are needed to validate this constraint.
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Affiliation(s)
| | - Enoch Chang
- Departments of Gastrointestinal Radiation Oncology
| | | | | | - Prajnan Das
- Departments of Gastrointestinal Radiation Oncology
| | | | | | | | | | | | | | - Denise Nebgen
- Gynecologic Oncology and Reproductive Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Christopher H Crane
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
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