1066 F. Ampil et al. monitored 3–5 days after starting prednisolone, showing a rapid decrease. After one week prednisolone was reduced to 15 mg OD. Transaminase levels continued to decrease and prednisolone was diminished to 10 mg, and later 5 mg OD as toxicity had returned to 3 ULN. No adverse events were experienced from prednisolone. Both patients continued pazopanib at 600 mg OD with confirmed stable disease during 38 weeks for Patient 1, and 18 weeks for Patient 2. Serum trough levels of pazopanib were measured under prednisolone treatment to confirm adequate exposure. Patients 1 and 2 had pazopanib levels of 26 mg/l and 22 mg/l, respectively. The target pazopanib exposure in patients with mRCC is 20.5 mg/l, which both patients met [7]. However, the target exposure in patients with STS needs to be defined yet. Liver serology for hepatitis B and C tested negative in both cases. In conclusion, both patients showed rapid decrease of transaminases, sustaining after reducing the dose of prednisolone, and consequently pazopanib could be continued (Figure 1). Discussion In patients with advanced STS therapeutic options are scarce. Pazopanib is the only licensed oral tyrosine kinase inhibitor for non-adipocytic soft tissue sarcoma. Therefore pazopanib discontinuation due to toxicity has major impact. Although our observations have to be explored further, we believe that management as described could be applied under close monitoring of liver enzymes to patients with pazopanib-induced hepatotoxicity, in particular when no therapeutic alternatives exist.
Declaration of interest: MV has no declaration of interests. NvE has obtained a research grant from GSK. WvdG received speaker’s fee and a research grant from GSK. The authors alone are responsible for the content and writing of the paper. References [1] Sternberg CN, Davis ID, Mardiak J, Szczylik C, Lee E, Wagstaff J, et al. Pazopanib in locally advanced or metastatic renal cell carcinoma: Results of a randomized phase III trial. J Clin Oncol 2010;28:1061–8. [2] van der Graaf WT, Blay JY, Chawla SP, Kim DW, Bui-Nguyen B, Casali PG, et al. Pazopanib for metastatic soft-tissue sarcoma (PALETTE): A randomised, doubleblind, placebo-controlled phase 3 trial. Lancet 2012;379: 1879–86. [3] Kapadia S, Hapani S, Choueiri TK, Wu S. Risk of liver toxicity with the angiogenesis inhibitor pazopanib in cancer patients. Acta Oncol 2013;52:1202–12. [4] UK GlaxoSmithKline: Votrient 200 mg and 400 mg film coated tablets – Summary of Product Characteristics (SPC), electronic Medicines Compendium. [cited 2014 Nov 3]. Available from: http://www.medicines.org.uk/emc/medicine/23148/SPC/Votrient 200 mg and 400 mg film coated tablets/ [5] Westgeest HM, van Erp NP, Honeywell RJ, Hoekstra R, Peters GJ, Verheul HM. Successful treatment of renal cell carcinoma with sorafenib after effective but hepatotoxic sunitinib exposure. J Clin Oncol 2013;31:e83–6. [6] Klempner SJ, Choueiri TK, Yee E, Doyle LA, Schuppan D, Atkins MB. Severe pazopanib-induced hepatotoxicity: Clinical and histologic course in two patients. J Clin Oncol 2012; 30:e264–8. [7] Suttle AB, Ball HA, Molimard M, Hutson TE, Carpenter C, Rajagopalan D, et al. Relationships between pazopanib exposure and clinical safety and efficacy in patients with advanced renal cell carcinoma. Br J Cancer 2014;111: 1909–16.
The prognostic utility of 18F-FDG-PET metabolic tumor response after chemoradiotherapy for locally advanced head and neck cancer Federico Ampil1, Gloria Caldito2, Carolyn Reiser3, Srinivas Devarakonda4, Amol Takalkar1, Cherie-Ann Nathan5 & Glenn Mills4 1Department
of Radiology, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 2Department of Biometry, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 3Department of Nursing, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 4Department of Medicine, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA and 5Department of Otolaryngology-Head Neck Surgery, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA Correspondence: F. L. Ampil, Louisiana State University Health, 1501 Kings Highway, Shreveport, Louisiana 71130, USA. Tel: 1 318 675 5334. Fax: 1 318 675 4697. E-mail: [email protected] (Received 3 November 2014; accepted 7 November 2014) ISSN 0284-186X print/ISSN 1651-226X online © 2015 Informa Healthcare DOI: 10.3109/0284186X.2014.987356
FDG-PET prognostic value after chemoradiotherapy in head and neck cancer 1067
To the Editor, As the selective use of 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis and treatment of advanced stage malignant disease has gained general acceptance at our institution, it becomes increasingly important to utilize this newer form of imaging towards understanding the effects of conventional chemoradiotherapy (CRT). Published studies [1–4] reveal that few data exist on the prognosis associated with the metabolic tumor response shown by FDG-PET after CRT in individuals with locally advanced head and neck carcinoma (LAHNC). It is in this context that we retrospectively reviewed our single institution’s experience of people treated by CRT for LAHNC. Forty-seven consecutive patients with pre- and post-treatment FDG-PET scans, treated between September 2003 to June 2011 and who were not lost to follow-up (Table I), were identified. PostTable I. Patient, tumor and treatment characteristics. Feature
No
%
Total Age at diagnosis (years) Median Range Non-elderly ( 65 years) Tumor stagea T1-T2 T3-T4 Nodal stagea N0–1 N2–3 Tumor site Oropharynx Otherb Tumor volumec 57 cm3 57 cm3 Other illnessd Absent Present Radiotherapy dosee (Gy) Mean Range Chemotherapyf 1 drug 2 drugs Follow-up (months) Median Range
47
100
56 35–83 42
89
12 35
25 75
10 37
21 79
23 24
49 51
18 19
49 51
15 32
32 68
70/50 60–70/50 30 17
64 36
36 8–130
aAmerican Joint Committee on Cancer staging system; bOral cavity, nasopharynx, hypopharynx, larynx, unknown site; cTumor volume determination using the formula π/6 (width) (length) (height); 37 evaluable patients; dHypertension, diabetes mellitus, asthma, congestive heart failure, atrial fibrillation, glaucoma, ulcerative colitis; eRadiation dose to the primary tumor bed-upper neck/lower neck; fCisplatin or Cetuximab; Cisplatin and 5-Fluorouracil.
therapy FDG-PET was usually performed 2–3 months after completion of combined therapy; interpretation of FDG-PET images by the visual analysis using a two-point scale was either a positive or negative scan. The technique of combined therapy is similar to that mentioned in our previous report [5]. Thirty-nine patients (83%) exhibited complete resolution of tumor and eight individuals (17%) had incomplete or absent responses. At a median follow-up of 36 months, the overall locoregional failure and distant metastasis rates were 17%. The two-year, overall survival rates in individuals with complete and incomplete disappearance of the neoplasms were 92% and 57%, respectively (p 0.02); the corresponding two-year, disease-free survival rates were 97% and 25% (p 0.01). After adjusting for patient age, primary and regional disease stage, site and volume of the neoplasm, number of chemotherapy drugs used, and the presence or absence of comorbidity, tumor response was the only significant independent predictor of prognosis. The evidence regarding the prognostic significance of metabolic tumor responses demonstrated by FDGPET in LAHNC is scarce. Several reports [1,2,4] about such post-treatment negative and positive scans, unfortunately, were not correlated with patient survival. Our findings appear to be in accord with those from the literature. In order to better understand the value of FDG-PET computed tomography in the assessment of treatment response and prediction of outcomes after CRT for LAHNC, Passero et al. [3] analyzed their 53-patient experience. Observations from their investigation included: 1) Complete response was documented by FDG-PET in 27 cases (53%); 2) The two-year, progression-free survival rates for people with a complete response and without total disappearance of tumor were 93% and 48%, respectively, p 0.0002. The limitations of the present study include: 1) Its retrospective design and the small sample; 2) A selection bias of patients who were deemed fit enough to benefit from CRT. We believe that the observations from this review can only add to the sparse literature about the prognostic relevance of FDG-PET noted treatment responses. Gupta et al. [6], in a meta-analysis of studies regarding the diagnostic merit of FDG-PET (CT) in the determination of treatment response, remarked that the negative predictive value of an after-therapy negative FDG-PET scan is exceptionally high and such finding is highly suggestive of absence of viable disease. In conclusion, FDG-PET imaging, aside from demonstrating metabolic tumor response, is also useful for its prognostic predictive potential. Nonetheless, outcome research requires more attention/validation in this evidencebased era.
1068 P. Doornaert et al. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References [1] Andrade RS, Heron DE, Degirmenci B, Filho PAA, Branstetter BF, Seethala RR, et al. Posttreatment assessment of response using FDG-PET CT for patients treated with definitive radiation therapy for head and neck cancers. Int J Radiat Oncol Biol Phys 2006;65:1315–22. [2] Ong SC, Schoder H, Lee NY, Patel SG, Carlson D, Fury M, et al. Clinical utility of 18F-FDG-PET/CT in assessing the neck after concurrent chemoradiotherapy for locoregional advanced head and neck cancer. J Nucl Med 2008;49: 532–40.
[3] Passero VA, Branstetter BF, Shuai Y, Heron DE, Gibson MK, Lai SY, et al. Response assessment by combined PET-CT scan versus CT scan alone using RECIST in patients with locally advanced head and neck cancer treated with chemoradiotherapy. Ann Oncol 2010;21:2278–83. [4] Rabalais AG, Walvekar R, Nuss D, McWhorter A, Wood C, Fields R, et al. Positron emission tomography-computed tomography surveillance for the node-positive neck after chemoradiotherapy. Laryngoscope 2009;119:1120–4. [5] Cho AH, Shah S, Ampil F, Bhartur S, Nathan CAO. N2 disease in patients with head and neck squamous cell cancer treated with chemoradiotherapy. Is there a role for posttreatment neck dissection? Arch Otolaryngol Head Neck Surg 2009;135:1112–8. [6] Gupta T, Master Z, Kannan S, Agarwal JP, Ghosh-Laskar S, Rangarajan V, et al. Diagnostic performance of post-treatment FDG PET or FDG PET/CT imaging in head and neck cancer: A systematic review and meta-analysis. Eur J Nucl Med Mol Imaging 2011;38:2083–95.
Use of diffusion-weighted magnetic resonance imaging (DW-MRI) to investigate the effect of chemoradiotherapy on the salivary glands Patricia Doornaert1, Max Dahele1, Redina Ljumanovic2, Remco de Bree3, Ben J. Slotman1 & Jonas A. Castelijns2 1Department
of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands, of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands and 3Department of Otolaryngology and Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands 2Department
To the Editor, Chemoradiotherapy (CRT) is the standard treatment for locally advanced head and neck cancer (HNC), offering comparable survival to surgery with the benefit of organ preservation. However, one of the most troublesome side effects is parotid (PG) and submandibular gland (SMG) toxicity leading to loss of gland function and hypo-salivation. The mechanism of salivary gland toxicity is incompletely understood and interventions for preventing or reversing hypo-salivation are currently limited [1]. The use of intensitymodulated radiotherapy (IMRT) to reduce salivary gland dose is now routine, but it is only partially effective [2,3]. Non-invasive imaging might help to better understand the response of the glands to CRT and identify salivary gland toxicity. This could in turn help to develop therapeutic strategies. A previous report suggested that diffusion-weighted magnetic resonance imaging (DW-MRI) before and after treatment might be a promising tool for investigating changes due to
radiotherapy [4]. Our goal was to image the effect of CRT on salivary glands using DW-MRI performed before, during and after CRT. Although DW-MRI in HNC is often performed with echo planar imaging (EPI) sequences, this technique is particularly prone to geometric distortions due to susceptibility artefacts. To overcome these possible disadvantages, we also used a non-EPI technique, (half-fourier acquisition single-shot turbo spin-echo, HASTE) [5]. Taking into account work that suggests heterogenous effects of radiation within glands, and different responses in PG and SMG, we analyzed sub-regions within individual glands and evaluated the parotid and submandibular glands separately [6–8]. We also looked for correlations between DW-MRI changes and planned radiation dose. In comparison with previous literature, the use of two different DW-MRI sequences, analysis of sub-regions in the glands and availability of imaging during, as well as before and after CRT, are strengths of this study.
Correspondence: Patricia Doornaert, Department of Radiation Oncology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. Tel: 31 20 4440414. Fax: 31 20 4440410. E-mail: [email protected]. (Received 1 September 2014; accepted 7 November 2014) ISSN 0284-186X print/ISSN 1651-226X online © 2015 Informa Healthcare DOI: 10.3109/0284186X.2014.987357
Copyright of Acta Oncologica is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Declaration of interest: MV has no declaration of interests. NvE has obtained a research grant from GSK. WvdG received speaker’s fee and a research grant from GSK. The authors alone are responsible for the content and writing of the paper. References [1] Sternberg CN, Davis ID, Mardiak J, Szczylik C, Lee E, Wagstaff J, et al. Pazopanib in locally advanced or metastatic renal cell carcinoma: Results of a randomized phase III trial. J Clin Oncol 2010;28:1061–8. [2] van der Graaf WT, Blay JY, Chawla SP, Kim DW, Bui-Nguyen B, Casali PG, et al. Pazopanib for metastatic soft-tissue sarcoma (PALETTE): A randomised, doubleblind, placebo-controlled phase 3 trial. Lancet 2012;379: 1879–86. [3] Kapadia S, Hapani S, Choueiri TK, Wu S. Risk of liver toxicity with the angiogenesis inhibitor pazopanib in cancer patients. Acta Oncol 2013;52:1202–12. [4] UK GlaxoSmithKline: Votrient 200 mg and 400 mg film coated tablets – Summary of Product Characteristics (SPC), electronic Medicines Compendium. [cited 2014 Nov 3]. Available from: http://www.medicines.org.uk/emc/medicine/23148/SPC/Votrient 200 mg and 400 mg film coated tablets/ [5] Westgeest HM, van Erp NP, Honeywell RJ, Hoekstra R, Peters GJ, Verheul HM. Successful treatment of renal cell carcinoma with sorafenib after effective but hepatotoxic sunitinib exposure. J Clin Oncol 2013;31:e83–6. [6] Klempner SJ, Choueiri TK, Yee E, Doyle LA, Schuppan D, Atkins MB. Severe pazopanib-induced hepatotoxicity: Clinical and histologic course in two patients. J Clin Oncol 2012; 30:e264–8. [7] Suttle AB, Ball HA, Molimard M, Hutson TE, Carpenter C, Rajagopalan D, et al. Relationships between pazopanib exposure and clinical safety and efficacy in patients with advanced renal cell carcinoma. Br J Cancer 2014;111: 1909–16.
The prognostic utility of 18F-FDG-PET metabolic tumor response after chemoradiotherapy for locally advanced head and neck cancer Federico Ampil1, Gloria Caldito2, Carolyn Reiser3, Srinivas Devarakonda4, Amol Takalkar1, Cherie-Ann Nathan5 & Glenn Mills4 1Department
of Radiology, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 2Department of Biometry, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 3Department of Nursing, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA, 4Department of Medicine, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA and 5Department of Otolaryngology-Head Neck Surgery, Louisiana State University Health and Feist-Weiller Cancer Center, Shreveport, Louisiana, USA Correspondence: F. L. Ampil, Louisiana State University Health, 1501 Kings Highway, Shreveport, Louisiana 71130, USA. Tel: 1 318 675 5334. Fax: 1 318 675 4697. E-mail: [email protected] (Received 3 November 2014; accepted 7 November 2014) ISSN 0284-186X print/ISSN 1651-226X online © 2015 Informa Healthcare DOI: 10.3109/0284186X.2014.987356
FDG-PET prognostic value after chemoradiotherapy in head and neck cancer 1067
To the Editor, As the selective use of 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis and treatment of advanced stage malignant disease has gained general acceptance at our institution, it becomes increasingly important to utilize this newer form of imaging towards understanding the effects of conventional chemoradiotherapy (CRT). Published studies [1–4] reveal that few data exist on the prognosis associated with the metabolic tumor response shown by FDG-PET after CRT in individuals with locally advanced head and neck carcinoma (LAHNC). It is in this context that we retrospectively reviewed our single institution’s experience of people treated by CRT for LAHNC. Forty-seven consecutive patients with pre- and post-treatment FDG-PET scans, treated between September 2003 to June 2011 and who were not lost to follow-up (Table I), were identified. PostTable I. Patient, tumor and treatment characteristics. Feature
No
%
Total Age at diagnosis (years) Median Range Non-elderly ( 65 years) Tumor stagea T1-T2 T3-T4 Nodal stagea N0–1 N2–3 Tumor site Oropharynx Otherb Tumor volumec 57 cm3 57 cm3 Other illnessd Absent Present Radiotherapy dosee (Gy) Mean Range Chemotherapyf 1 drug 2 drugs Follow-up (months) Median Range
47
100
56 35–83 42
89
12 35
25 75
10 37
21 79
23 24
49 51
18 19
49 51
15 32
32 68
70/50 60–70/50 30 17
64 36
36 8–130
aAmerican Joint Committee on Cancer staging system; bOral cavity, nasopharynx, hypopharynx, larynx, unknown site; cTumor volume determination using the formula π/6 (width) (length) (height); 37 evaluable patients; dHypertension, diabetes mellitus, asthma, congestive heart failure, atrial fibrillation, glaucoma, ulcerative colitis; eRadiation dose to the primary tumor bed-upper neck/lower neck; fCisplatin or Cetuximab; Cisplatin and 5-Fluorouracil.
therapy FDG-PET was usually performed 2–3 months after completion of combined therapy; interpretation of FDG-PET images by the visual analysis using a two-point scale was either a positive or negative scan. The technique of combined therapy is similar to that mentioned in our previous report [5]. Thirty-nine patients (83%) exhibited complete resolution of tumor and eight individuals (17%) had incomplete or absent responses. At a median follow-up of 36 months, the overall locoregional failure and distant metastasis rates were 17%. The two-year, overall survival rates in individuals with complete and incomplete disappearance of the neoplasms were 92% and 57%, respectively (p 0.02); the corresponding two-year, disease-free survival rates were 97% and 25% (p 0.01). After adjusting for patient age, primary and regional disease stage, site and volume of the neoplasm, number of chemotherapy drugs used, and the presence or absence of comorbidity, tumor response was the only significant independent predictor of prognosis. The evidence regarding the prognostic significance of metabolic tumor responses demonstrated by FDGPET in LAHNC is scarce. Several reports [1,2,4] about such post-treatment negative and positive scans, unfortunately, were not correlated with patient survival. Our findings appear to be in accord with those from the literature. In order to better understand the value of FDG-PET computed tomography in the assessment of treatment response and prediction of outcomes after CRT for LAHNC, Passero et al. [3] analyzed their 53-patient experience. Observations from their investigation included: 1) Complete response was documented by FDG-PET in 27 cases (53%); 2) The two-year, progression-free survival rates for people with a complete response and without total disappearance of tumor were 93% and 48%, respectively, p 0.0002. The limitations of the present study include: 1) Its retrospective design and the small sample; 2) A selection bias of patients who were deemed fit enough to benefit from CRT. We believe that the observations from this review can only add to the sparse literature about the prognostic relevance of FDG-PET noted treatment responses. Gupta et al. [6], in a meta-analysis of studies regarding the diagnostic merit of FDG-PET (CT) in the determination of treatment response, remarked that the negative predictive value of an after-therapy negative FDG-PET scan is exceptionally high and such finding is highly suggestive of absence of viable disease. In conclusion, FDG-PET imaging, aside from demonstrating metabolic tumor response, is also useful for its prognostic predictive potential. Nonetheless, outcome research requires more attention/validation in this evidencebased era.
1068 P. Doornaert et al. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References [1] Andrade RS, Heron DE, Degirmenci B, Filho PAA, Branstetter BF, Seethala RR, et al. Posttreatment assessment of response using FDG-PET CT for patients treated with definitive radiation therapy for head and neck cancers. Int J Radiat Oncol Biol Phys 2006;65:1315–22. [2] Ong SC, Schoder H, Lee NY, Patel SG, Carlson D, Fury M, et al. Clinical utility of 18F-FDG-PET/CT in assessing the neck after concurrent chemoradiotherapy for locoregional advanced head and neck cancer. J Nucl Med 2008;49: 532–40.
[3] Passero VA, Branstetter BF, Shuai Y, Heron DE, Gibson MK, Lai SY, et al. Response assessment by combined PET-CT scan versus CT scan alone using RECIST in patients with locally advanced head and neck cancer treated with chemoradiotherapy. Ann Oncol 2010;21:2278–83. [4] Rabalais AG, Walvekar R, Nuss D, McWhorter A, Wood C, Fields R, et al. Positron emission tomography-computed tomography surveillance for the node-positive neck after chemoradiotherapy. Laryngoscope 2009;119:1120–4. [5] Cho AH, Shah S, Ampil F, Bhartur S, Nathan CAO. N2 disease in patients with head and neck squamous cell cancer treated with chemoradiotherapy. Is there a role for posttreatment neck dissection? Arch Otolaryngol Head Neck Surg 2009;135:1112–8. [6] Gupta T, Master Z, Kannan S, Agarwal JP, Ghosh-Laskar S, Rangarajan V, et al. Diagnostic performance of post-treatment FDG PET or FDG PET/CT imaging in head and neck cancer: A systematic review and meta-analysis. Eur J Nucl Med Mol Imaging 2011;38:2083–95.
Use of diffusion-weighted magnetic resonance imaging (DW-MRI) to investigate the effect of chemoradiotherapy on the salivary glands Patricia Doornaert1, Max Dahele1, Redina Ljumanovic2, Remco de Bree3, Ben J. Slotman1 & Jonas A. Castelijns2 1Department
of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands, of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands and 3Department of Otolaryngology and Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands 2Department
To the Editor, Chemoradiotherapy (CRT) is the standard treatment for locally advanced head and neck cancer (HNC), offering comparable survival to surgery with the benefit of organ preservation. However, one of the most troublesome side effects is parotid (PG) and submandibular gland (SMG) toxicity leading to loss of gland function and hypo-salivation. The mechanism of salivary gland toxicity is incompletely understood and interventions for preventing or reversing hypo-salivation are currently limited [1]. The use of intensitymodulated radiotherapy (IMRT) to reduce salivary gland dose is now routine, but it is only partially effective [2,3]. Non-invasive imaging might help to better understand the response of the glands to CRT and identify salivary gland toxicity. This could in turn help to develop therapeutic strategies. A previous report suggested that diffusion-weighted magnetic resonance imaging (DW-MRI) before and after treatment might be a promising tool for investigating changes due to
radiotherapy [4]. Our goal was to image the effect of CRT on salivary glands using DW-MRI performed before, during and after CRT. Although DW-MRI in HNC is often performed with echo planar imaging (EPI) sequences, this technique is particularly prone to geometric distortions due to susceptibility artefacts. To overcome these possible disadvantages, we also used a non-EPI technique, (half-fourier acquisition single-shot turbo spin-echo, HASTE) [5]. Taking into account work that suggests heterogenous effects of radiation within glands, and different responses in PG and SMG, we analyzed sub-regions within individual glands and evaluated the parotid and submandibular glands separately [6–8]. We also looked for correlations between DW-MRI changes and planned radiation dose. In comparison with previous literature, the use of two different DW-MRI sequences, analysis of sub-regions in the glands and availability of imaging during, as well as before and after CRT, are strengths of this study.
Correspondence: Patricia Doornaert, Department of Radiation Oncology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. Tel: 31 20 4440414. Fax: 31 20 4440410. E-mail: [email protected]. (Received 1 September 2014; accepted 7 November 2014) ISSN 0284-186X print/ISSN 1651-226X online © 2015 Informa Healthcare DOI: 10.3109/0284186X.2014.987357
Copyright of Acta Oncologica is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
