Information Needs Expressed During Patient-Oriented Oncology Consultations: Quantity, Variation, and Barriers.

High-quality oncology consultation includes patient-oriented communication tailored to patients' individualized needs. Common methods used in studies to increase question-asking are prompt lists and coaching pre-consultations. However, our patients were encouraged to ask questions by the physician during their visit. We aimed to estimate the quantity, nature, and variation of their questions when they were invited to ask by their oncologist. During radiotherapy consultations from 2012 to 2016, patient's questions were deliberately elicited and physician-transcribed. We derived mean and median number of questions per patient, variance by patient factors, and a taxonomy of subjects using thematic analysis. Three hundred ninety-six patients asked 2386 questions, median asked per patient = 6 (interquartile range = 4). We found significant variance with age (mean = 6.9 questions for < 60 years, 5.4 for ≥ 70 years) p = 0.018, insurance type (mean = 4.7 for Medicaid, 7.2 for private insurance) p = 0.0004, and tumor site (mean number of questions: skin = 4.6, lymphoma = 5.2, lung = 5.8, breast = 6.1, prostate = 6.3, rectum = 6.7 head and neck = 6.9, brain = 7.0, bladder = 7.2, anus = 8.8, others = 5.8) p = 0.0440. Of the diverse set of 57 topics, the commonest were 1. logistics, 2. radiotherapy details, 3. side effects, 4. diagnosis, and 5. stage and prognosis. Only 17 topics were asked by more > 10% of patients and 40 topics were asked by < 10% of patients. With median of 6 questions, it is practicable to routinely elicit and address individualized information needs. Potential barriers may be older and underinsured patients. The wide variety of topics, often pertaining to individuals' case, suggests that cancer clinicians should take time-out during consultation to elicit patients' questions to accomplish best-practice communication.

Definitive radiotherapy for a head and neck Merkel cell carcinoma and comprehensive nodal volumes: a case for using a computer-designed variable-thickness compensator to reduce risk and severity of mucositis.

When contemplating how to treat head and neck primary cancers and regional lymph nodes with radiotherapy, we often select the contemporary intensity-modulated radiotherapy (IMRT) without much consideration of older methods that may give fewer side effects and be more cost-effective. For an 87-year-old female with a 1.5-cm Merkel cell carcinoma (MCC) located 1.5 cm lateral to the orbital rim, we were challenged to deliver 50 Gy to comprehensive elective nodal regions and 70 Gy to the primary. We were particularly concerned about the potential adverse acute effects of radiotherapy to mucosal structures in this elderly female. Acute mucositis could impair nutrition, quality of life, and treatment intensity especially given her age. We compared 3 techniques that are appropriate for this target: step-and-shoot IMRT, matched electron fields (MEF), and electron conformal therapy (BolusECT™). We selected and treated her with BolusECT™ because of better sparing of larynx, pharynx, oral cavity and lips, and shortest treatment time. This is a reasonable option for treating ipsilateral head and neck target volumes at centers where only these 3 techniques are available.

Routine bladder cancer treatment dictates divergence from trial-derived regimens: Results of treatment at 44 radiotherapy centers.

PURPOSE: To assess characteristics and outcome of patients treated with radiotherapy for muscle-invasive bladder cancer at 44 community-based radiotherapy centers and compare these to those on clinical trials. MATERIALS AND METHODS: We reviewed 155 patients who had been treated from 2010 to 2014. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Results were compared to a pooled analysis of 6 Radiation Therapy Oncology Group (RTOG) protocols. RESULTS: What stood out was that our patients' characteristics were significantly inferior than those on RTOG studies: lower rate of complete transurethral resection of bladder tumor: 36.8% vs. 70% (P<0.0001), higher median age: 79 years vs. 66 (P<0.0001), more medically inoperable: (51.0%) vs. 0% in RTOG (P<0.001), and 46.9% had refused surgery. Fewer patients underwent concurrent chemotherapy: 56.1% vs. 100% (P<0.0001). It was also striking that at median follow-up 12.6 months (range: 3.1-49.2), the 36-month overall survival was 51.3% for those who refused surgery vs. 24.5% for medically inoperable (P = 0.009); 58.1% with complete transurethral resection of bladder tumor vs. 29.8% if incomplete (P = 0.07); 54.3% with chemoradiotherapy (CRT) vs. 17.2% without (P = 0.03); 66.3% for those who refused surgery and had CRT vs. 38.9% for medically inoperable who had CRT (P = 0.04). CONCLUSIONS: The cohort at community-based centers was older, more medically inoperable, and less likely to receive CRT than clinical trial patients. This suggests that we may not be able to apply trial-derived regimens for many patients in this setting. There is a pressing need to find treatment options for such patients, especially given the aging population. Survival of medically operable CRT patients was comparable to results of RTOG protocols notwithstanding this study's smaller sample size, retrospective nature and suboptimal documentation of patient characteristics.

Prediction of neck dissection requirement after definitive radiotherapy for head-and-neck squamous cell carcinoma.

BACKGROUND: This analysis was undertaken to assess the need for planned neck dissection in patients with a complete response (CR) of involved nodes after irradiation and to determine the benefit of a neck dissection in those with less than CR by tumor site. METHODS: Our cohort included 880 patients with T1-4, N1-3M0 squamous cell carcinoma of the oropharynx, larynx, or hypopharynx who received treatment between 1994 and 2004. Survival curves were calculated by the Kaplan-Meier Method, comparisons of rates with the log-rank test and prognostic factors by Cox's proportional hazard model. RESULTS: Nodal CR occurred in 377 (43%) patients, of whom 365 patients did not undergo nodal dissection. The 5-year actuarial regional control rate of patients with CR was 92%. Two hundred sixty-eight of the remaining patients (53%) underwent neck dissections. The 5-year actuarial regional control rate for patients without a CR was 84%. Those who had a neck dissection fared better with 5-year actuarial regional control rates of 90% and 76% for those operated and those not operated (p < 0.001). Variables associated with poorer regional control rates included higher T and N stage, non-oropharynx cancers, non-CR, both clinical and pathological. CONCLUSIONS: With 92% 5-year neck control rate without neck dissection after CR, there is little justification for systematic neck dissection. The addition of a neck dissection resulted in higher neck control after partial response though patients with viable tumor on pathology specimens had poorer outcomes. The identification of that subgroup that benefits from additional treatment remains a challenge.

Geographic access to cancer care: a disparity and a solution.

BACKGROUND The rising cancer incidence in developing countries outpaces easy access to care. Time and effort spent on travel for care is a burden to patients and detracts from patient centredness, efficiency, and equitability. In Trinidad and Tobago, significant distress was observed among patients who made long journeys to the single public cancer clinic. The journey time among non-radiotherapy patients was measured. METHODS Over 19 weekdays in June 2007, the study assessed estimated travel time per visit (ETT), reason for visit for care, and number of visits per patient during their treatment course up to the time of study, and compared the findings with ETT to nearest centres for the US population. RESULTS 1447 episodes of care utilised 5296 h of patient travel time. Median ETT was 3.75 h (IQR 2-5 h, range 0.5-9 h). 74.1% of patients spent 2.25-9 h ETT. 44% of patients spent >4 h ETT. Median number of visits per patient was 34 (IQR 23-43; range 13-62). Median total ETT per patient was 127.5 h. Median ETT to the centre (1.75 h) was eight times greater than in the USA (13 min). More than 70% of patients attended for reasons other than chemotherapy. CONCLUSIONS Cancer patients endured a burden of long travel times in 2007. The prevailing policy of the Ministry of Health to build a single centralised modern centre would not have alleviated this burden. Based on these findings, three outlying cancer clinics were created which now provide non-radiotherapy oncology management of patients nearer their homes.

IMRT reirradiation of head and neck cancer-disease control and morbidity outcomes.

PURPOSE: Institutional and cooperative group experience has demonstrated the feasibility of reirradiation for head and neck cancer. Limited data are available regarding the use of intensity-modulated radiotherapy (IMRT) for this indication. We reviewed our initial experience using IMRT for previously irradiated head and neck cancer patients. METHODS AND MATERIALS: Records of 78 consecutive patients reirradiated with IMRT for head and neck cancer between 1999 and 2004 were reviewed; 74 cases were analyzed. Reirradiation was defined as any overlap between original and new radiation treatment volumes regardless of the time interval between initial and subsequent treatment. Severe reirradiation-related toxicity was defined as toxic events resulting in hospitalization, corrective surgery, or patient death. Longitudinal estimates of survival were calculated by Kaplan-Meier technique. RESULTS: Twenty (27%) patients underwent salvage surgical resection and 36 (49%) patients received chemotherapy. Median follow-up from reirradiation was 25 months. Median time interval between initial radiation and reirradiation was 46 months. Median reirradiation dose was 60 Gy. Median lifetime radiation dose was 116.1 Gy. The 2-year overall survival and locoregional control rates were 58% and 64%, respectively. Severe reirradiation related toxicity occurred in 15 patients (20%); one treatment-related death was observed. CONCLUSIONS: The use of IMRT for reirradiation of recurrent or second primary head and neck cancers resulted in encouraging local control and survival. Reirradiation-related morbidity was significant, but may be less severe than previously published reports using conventional techniques.

Postoperative external beam radiotherapy for differentiated thyroid cancer: outcomes and morbidity with conformal treatment.

PURPOSE: To review institutional outcomes for patients treated for differentiated thyroid cancer with postoperative conformal external beam radiotherapy (EBRT). METHODS AND MATERIALS: This is a single-institution retrospective review of 131 consecutive patients with differentiated thyroid cancer who underwent EBRT between January 1996 and December 2005. Histologic diagnoses included 104 papillary, 21 follicular, and six mixed papillary-follicular types. American Joint Committee on Cancer stage distribution was Stage III in 2 patients, Stage IVa-IVc in 128, and not assessable in 1. Thirty-four patients (26%) had high-risk histologic types and 76 (58%) had recurrent disease. Extraglandular disease spread was seen in 126 patients (96%), microscopically positive surgical margins were seen in 62 patients (47%), and gross residual disease was seen in 15 patients (11%). Median EBRT dose was 60 Gy (range, 38-72 Gy). Fifty-seven patients (44%) were treated with intensity-modulated radiotherapy (IMRT) to a median dose of 60 Gy (range, 56-66 Gy). Median follow-up was 38 months (range, 0-134 months). RESULTS: Kaplan-Meier estimates of locoregional relapse-free survival, disease-specific survival, and overall survival at 4 years were 79%, 76%, and 73%, respectively. On multivariate analysis, high-risk histologic features and gross residual disease predicted for inferior locoregional relapse-free survival, whereas high-risk histologic features, M1 disease, and gross residual disease predicted for inferior disease-specific and overall survival. The IMRT did not impact on survival outcomes, but was associated with less frequent severe late morbidity (12% vs. 2%). CONCLUSIONS: Postoperative conformal EBRT provides durable locoregional disease control for patients with high-risk differentiated thyroid cancer if disease is reduced to microscopic burden. Patients with gross disease face significantly worse outcomes. The IMRT may significantly reduce chronic radiation morbidity, but requires additional study.

Performance evaluation of automatic anatomy segmentation algorithm on repeat or four-dimensional computed tomography images using deformable image registration method.

PURPOSE: Auto-propagation of anatomic regions of interest from the planning computed tomography (CT) scan to the daily CT is an essential step in image-guided adaptive radiotherapy. The goal of this study was to quantitatively evaluate the performance of the algorithm in typical clinical applications. METHODS AND MATERIALS: We had previously adopted an image intensity-based deformable registration algorithm to find the correspondence between two images. In the present study, the regions of interest delineated on the planning CT image were mapped onto daily CT or four-dimensional CT images using the same transformation. Postprocessing methods, such as boundary smoothing and modification, were used to enhance the robustness of the algorithm. Auto-propagated contours for 8 head-and-neck cancer patients with a total of 100 repeat CT scans, 1 prostate patient with 24 repeat CT scans, and 9 lung cancer patients with a total of 90 four-dimensional CT images were evaluated against physician-drawn contours and physician-modified deformed contours using the volume overlap index and mean absolute surface-to-surface distance. RESULTS: The deformed contours were reasonably well matched with the daily anatomy on the repeat CT images. The volume overlap index and mean absolute surface-to-surface distance was 83% and 1.3 mm, respectively, compared with the independently drawn contours. Better agreement (>97% and <0.4 mm) was achieved if the physician was only asked to correct the deformed contours. The algorithm was also robust in the presence of random noise in the image. CONCLUSION: The deformable algorithm might be an effective method to propagate the planning regions of interest to subsequent CT images of changed anatomy, although a final review by physicians is highly recommended.

Comparison of 2D radiographic images and 3D cone beam computed tomography for positioning head-and-neck radiotherapy patients.

PURPOSE: To assess the positioning accuracy using two-dimensional kilovoltage (2DkV) imaging and three-dimensional cone beam CT (CBCT) in patients with head and neck (H&N) cancer receiving radiation therapy. To assess the benefit of patient-specific headrest. MATERIALS AND METHODS: All 21 patients studied were immobilized using thermoplastic masks with either a patient-specific vacuum bag (11 of 21, IMA) or standard clear plastic (10 of 21, IMB) headrests. Each patient was imaged with a pair of orthogonal 2DkV images in treatment position using onboard imaging before the CBCT procedure. The 2DkV and CBCT images were acquired weekly during the same session. The 2DkV images were reviewed by oncologists and also analyzed by a software tool based on mutual information (MI). RESULTS: Ninety-eight pairs of assessable 2DkV-CBCT alignment sets were obtained. Systematic and random errors were <1.6 mm for both 2DkV and CBCT alignments. When we compared shifts determined by CBCT and 2DkV for the same patient setup, statistically significant correlations were observed in all three major directions. Among all CBCT couch shifts, 4.1% > or = 0.5 cm and 18.7% > or = 0.3 cm, whereas among all 2DkV (MI) shifts, 1.7% > or = 0.5 cm and 11.2% > or = 0.3 cm. Statistically significant difference was found on anteroposterior direction between IMA and IMB with the CBCT alignment only. CONCLUSIONS: The differences between 2D and 3D alignments were mainly caused by the relative flexibility of certain H&N structures and possibly by rotation. Better immobilization of the flexible neck is required to further reduce the setup errors for H&N patients receiving radiotherapy.

Outcomes after radiotherapy for basaloid squamous cell carcinoma of the head and neck: a case-control study.

BACKGROUND: Basaloid squamous cell carcinoma (BSCC) is an uncommon, high-grade variant of squamous cell carcinoma (SCC) of the head and neck. Its poorer prognosis compared with common SCC remains controversial. The authors investigated the outcomes of patients with BSCC who received radiotherapy and compared them with the outcomes of patients with SCC. METHODS: From 1994 to 2004, 1007 patients received radiotherapy for head and neck carcinoma with lymph node involvement. The histologic types consisted of 51 BSCC, 431 poorly differentiated SCC (PSCC), and 525 well or moderately differentiated SCC (WMSCC). A case-control analysis was performed with BSCC matched against both PSCC and WMSCC to compare disease-control and survival rates. RESULTS: Patients with BSCC received treatment modalities similar to those received by patients with SCC: They received induction chemotherapy (12%) or concurrent chemotherapy (33%), and a median radiation dose of 70 Gray. Posttreatment viable tumor was present in 44%, 13%, and 28% of neck dissection specimens from patients with BSCC, PSCC, and WMSCC, respectively. The 5-year disease-free survival rates (63%, 77%, and 76%, respectively) and overall survival rates (85%, 70%, and 71%, respectively) demonstrated no statistically significant differences for BSCC, PSCC, or WMSCC, respectively. CONCLUSIONS: In this study, a poorer prognosis could not be demonstrated for irradiated patients with BSCC compared with either PSCC or WMSCC. All patients in this study had positive lymph node status, and the majority of patients (84%) had oropharyngeal cancer. The BSCC cohort did have a relatively high rate of viable tumor in their posttreatment neck dissections, and they had a relatively high rate of distant disease. On the basis of the high rate of lung metastases and the possibility of efficient salvage, the authors recommend obtaining a chest computed tomography scan during initial staging and follow-up.

Outcomes after radiotherapy for squamous cell carcinoma of the eyelid.

BACKGROUND: Squamous cell carcinoma (SCC) of the eyelid is a rare malignancy with metastatic potential. In the current study, the outcomes of patients with SCC of the eyelid were evaluated after definitive and postoperative radiation therapy. METHODS: The medical records of all patients treated with radiotherapy for SCC of the eyelid at 1 institution between 1950 and 2005 were reviewed. Patient records were analyzed for clinical characteristics, pathologic features, radiation techniques, and outcomes. Survival rates were calculated using the Kaplan-Meier method; factors affecting survival were assessed using the log-rank test. RESULTS: During the study period, 39 patients with 42 eyelid SCCs were treated with radiotherapy. Thirty-two tumors were treated with primary radiotherapy and 10 were treated with postoperative radiotherapy after wide local excision. Surviving patients were followed for a median of 76 months. The 5-year disease-specific and overall survival rates for all patients were 86% and 71%, respectively. At 5 years, local, regional, and distant disease control rates for all tumors were 88%, 95%, and 97%, respectively. There were no significant differences in the 5-year local, regional, and distant control rates between tumors treated with definitive and those treated with postoperative radiotherapy. There were no grade 3 or 4 complications. CONCLUSIONS: Primary radiotherapy for SCC of the eyelid provides excellent locoregional control with reasonable complication rates and should be considered an alternative to surgery in selected patients.

Parotid gland dose in intensity-modulated radiotherapy for head and neck cancer: is what you plan what you get?

PURPOSE: To quantify the differences between planned and delivered parotid gland and target doses, and to assess the benefits of daily bone alignment for head and neck cancer patients treated with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: Eleven head and neck cancer patients received two CT scans per week with an in-room CT scanner over the course of their radiotherapy. The clinical IMRT plans, designed with 3-mm to 4-mm planning margins, were recalculated on the repeat CT images. The plans were aligned using the actual treatment isocenter marked with radiopaque markers (BB) and bone alignment to the cervical vertebrae to simulate image-guided setup. In-house deformable image registration software was used to map daily dose distributions to the original treatment plan and to calculate a cumulative delivered dose distribution for each patient. RESULTS: Using conventional BB alignment led to increases in the parotid gland mean dose above the planned dose by 5 to 7 Gy in 45% of the patients (median, 3.0 Gy ipsilateral, p = 0.026; median, 1.0 Gy contralateral, p = 0.016). Use of bone alignment led to reductions relative to BB alignment in 91% of patients (median, 2 Gy; range, 0.3-8.3 Gy; 15 of 22 parotids improved). However, the parotid dose from bone alignment was still greater than planned (median, 1.0 Gy, p = 0.007). Neither approach affected tumor dose coverage. CONCLUSIONS: With conventional BB alignment, the parotid gland mean dose was significantly increased above the planned mean dose. Using daily bone alignment reduced the parotid dose compared with BB alignment in almost all patients. A 3- to 4-mm planning margin was adequate for tumor dose coverage.

Reduce in variation and improve efficiency of target volume delineation by a computer-assisted system using a deformable image registration approach.

PURPOSE: To determine whether a computer-assisted target volume delineation (CAT) system using a deformable image registration approach can reduce the variation of target delineation among physicians with different head and neck (HN) IMRT experiences and reduce the time spent on the contouring process. MATERIALS AND METHODS: We developed a deformable image registration method for mapping contours from a template case to a patient case with a similar tumor manifestation but different body configuration. Eight radiation oncologists with varying levels of clinical experience in HN IMRT performed target delineation on two HN cases, one with base-of-tongue (BOT) cancer and another with nasopharyngeal cancer (NPC), by first contouring from scratch and then by modifying the contours deformed by the CAT system. The gross target volumes were provided. Regions of interest for comparison included the clinical target volumes (CTVs) and normal organs. The volumetric and geometric variation of these regions of interest and the time spent on contouring were analyzed. RESULTS: We found that the variation in delineating CTVs from scratch among the physicians was significant, and that using the CAT system reduced volumetric variation and improved geometric consistency in both BOT and NPC cases. The average timesaving when using the CAT system was 26% to 29% for more experienced physicians and 38% to 47% for the less experienced ones. CONCLUSIONS: A computer-assisted target volume delineation approach, using a deformable image-registration method with template contours, was able to reduce the variation among physicians with different experiences in HN IMRT while saving contouring time.

Postoperative radiotherapy for maxillary sinus cancer: long-term outcomes and toxicities of treatment.

PURPOSE: To determine the effects of three changes in radiotherapy technique on the outcomes for patients irradiated postoperatively for maxillary sinus cancer. METHODS AND MATERIALS: The data of 146 patients treated between 1969 and 2002 were reviewed. The patients were separated into two groups according to the date of treatment. Group 1 included 90 patients treated before 1991 and Group 2 included 56 patients treated after 1991, when the three changes were implemented. The outcomes were compared between the two groups. RESULTS: No differences were found in the 5-year overall survival, recurrence-free survival, local control, nodal control, or distant metastasis rates between the two groups (51% vs. 62%, 51% vs. 57%, 76% vs. 70%, 82% vs. 83%, and 28% vs. 17% for Groups 1 and 2, respectively). The three changes were to increase the portals to cover the base of the skull in patients with perineural invasion, reducing their risk of local recurrence; the addition of elective neck irradiation in patients with squamous or undifferentiated histologic features, improving the nodal control, distant metastasis, and recurrence-free survival rates (64% vs. 93%, 20% vs. 3%, and 45% vs. 67%, respectively; p < 0.05 for all comparisons); and improving the dose distributions within the target volume, reducing the late Grade 3-4 complication rates (34% in Group 1 vs. 8% in Group 2, p = 0.014). Multivariate analysis revealed advancing age, the need for enucleation, and positive margins as independent predictors of worse overall survival. The need for enucleation also predicted for worse local control. CONCLUSION: The three changes in radiotherapy technique improved the outcomes for select patients as predicted. Despite these changes, little demonstrable overall improvement occurred in local control or survival for these patients and additional work must be done.

The effect of dental artifacts, contrast media, and experience on interobserver contouring variations in head and neck anatomy.

OBJECTIVES: To investigate interobserver variability in the delineation of head-and-neck (H&N) anatomic structures on CT images, including the effects of image artifacts and observer experience. METHODS: Nine observers (7 radiation oncologists, 1 surgeon, and 1 physician assistant) with varying levels of H&N delineation experience independently contoured H&N gross tumor volumes and critical structures on radiation therapy treatment planning CT images alongside reference diagnostic CT images for 4 patients with oropharynx cancer. Image artifacts from dental fillings partially obstructed 3 images. Differences in the structure volumes, center-of-volume positions, and boundary positions (1 SD) were measured. In-house software created three-dimensional overlap distributions, including all observers. The effects of dental artifacts and observer experience on contouring precision were investigated, and the need for contrast media was assessed. RESULTS: In the absence of artifacts, all 9 participants achieved reasonable precision (1 SD < or =3 mm all boundaries). The structures obscured by dental image artifacts had larger variations when measured by the 3 metrics (1 SD = 8 mm cranial/caudal boundary). Experience improved the interobserver consistency of contouring for structures obscured by artifacts (1 SD = 2 mm cranial/caudal boundary). CONCLUSIONS: Interobserver contouring variability for anatomic H&N structures, specifically oropharyngeal gross tumor volumes and parotid glands, was acceptable in the absence of artifacts. Dental artifacts increased the contouring variability, but experienced participants achieved reasonable precision even with artifacts present. With a staging contrast CT image as a reference, delineation on a noncontrast treatment planning CT image can achieve acceptable precision.

Multiple regions-of-interest analysis of setup uncertainties for head-and-neck cancer radiotherapy.

PURPOSE: To analyze three-dimensional setup uncertainties for multiple regions of interest (ROIs) in head-and-neck region. METHODS AND MATERIALS: In-room computed tomography (CT) scans were acquired using a CT-on-rails system for 14 patients. Three separate bony ROIs were defined: C2 and C6 vertebral bodies and the palatine process of the maxilla. Translational shifts of 3 ROIs were calculated relative to the marked isocenter on the immobilization mask. RESULTS: The shifts for all 3 ROIs were highly correlated. However, noticeable differences on the order of 2-6 mm existed between any 2 ROIs, indicating the flexibility and/or rotational effect in the head-and-neck region. The palatine process of the maxilla had the smallest right-left shifts because of the tight lateral fit in the face mask, but the largest superior-inferior movement because of in-plane rotation and variations in jaw positions. The neck region (C6) had the largest right-left shifts. The positioning mouthpiece was found effective in reducing variations in the superior-inferior direction. There was no statistically significant improvement for using the S-board (8 out of 14 patients) vs. the short face mask. CONCLUSIONS: We found variability in setup corrections for different regions of head-and-neck anatomy. These relative positional variations should be considered when making setup corrections or designing treatment margins.

Impact of changes to the American Joint Committee on Cancer T classification on outcome prediction in patients with oropharyngeal cancer.

BACKGROUND: The efficacy of the current 6th edition of the American Joint Committee on Cancer (AJCC) tumor staging criteria in improving outcome prediction for patients with oropharyngeal cancer was analyzed. METHODS: From the database of the Department of Radiation Oncology at the University of Texas M. D. Anderson Cancer Center the authors identified 875 patients irradiated at the study institution for oropharyngeal cancer between January 1975 and December 1998. The tumors were restaged based on the 6th edition of AJCC tumor staging criteria to reassess the original outcome predictions, specifically overall survival (OS) and local control (LC). RESULTS: Applying the new 6th edition staging system resulted in the following T classification distributions: T2, 301 tumors (34%); T3, 248 tumors (28%); T4a, 224 tumors (26%), and T4b, 102 tumors (12%). The 5-year and 10-year OS rates based on the new system were: T2, 65% and 45%; T3, 44% and 28%; T4a, 30% and 23%; and T4b, 26% and 12%, respectively. The 5-year and 10-year actuarial local LC rates based on the new system were: T2, 85% and 83%; T3, 73% and 71%; T4a, 61% and 58%; and T4b, 42% and 42%, respectively. Differences in OS and LC rates stratified by stage were found to be statistically significant both for the overall distribution of survival and pairwise comparisons of the 4 tumor stage groups. CONCLUSIONS: The modifications established in the 6th edition of the AJCC tumor staging system for oropharyngeal tumors appear to be useful to distinguish prognostic groups for both LC and OS based on tumor stage.

Comparison of treatment volumes and techniques in prostate cancer radiation therapy.

OBJECTIVE: To compare dose-volume histograms (DVHs) for 3 target volumes (group 1, prostate + seminal vesicles + pelvic lymph nodes; group 2, prostate + seminal vesicles; group 3, prostate only) to determine the difference in dose to normal structures (rectum, bladder, and femoral heads) while controlling for target dose using 3-dimensional conformal radiation therapy (3DCRT) versus intensity modulated radiation therapy (IMRT). METHODS: Ten patients with localized prostate cancer were randomly selected. 3DCRT and IMRT planning were done to deliver 75.6 Gy to the prostate, 50.4 Gy to the pelvic nodes, and 55.8 Gy to the seminal vesicles at a standard fractionation of 1.8 Gy. An additional plan delivering 75.6 Gy to the seminal vesicles using IMRT was run. DVHs were compared for 3DCRT and IMRT. RESULTS: In all 3 groups, the percent rectum receiving > or =70 Gy, > or =60 Gy, and > or =40 Gy was significantly less for IMRT than for 3DCRT. Increasing target volumes, as necessary for pelvic nodal irradiation, overall did not result in higher rectal doses for IMRT. With 3DCRT, however, larger target volumes did increase the amount of rectum irradiated. Similar results were obtained for the femoral heads whereas results for the bladder were mixed. CONCLUSION: When compared with 3DCRT, IMRT delivered equivalent or higher doses to the target volume with greater sparing of critical organs. Because dose-volume parameters have been shown to relate to toxicity, IMRT would appear to be the favored technique for prostate cancer radiation, particularly with regard to nodal treatment.

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

PURPOSE: To determine the effectiveness of noncoplanar beam configurations and the benefit of plans using fewer but optimally placed beams designed by a parallelized multiple-resolution beam angle optimization (PMBAO) approach. METHODS AND MATERIALS: The PMBAO approach uses a combination of coplanar and noncoplanar beam configurations for intensity-modulated radiation therapy (IMRT) treatment planning of paranasal sinus cancers. A smaller number of beams (e.g. 3) are first used to explore the solution space to determine the best and worst beam directions. The results of this exploration are then used as a starting point for determining an optimum beam orientation configuration with more beams (e.g. 5). This process is parallelized using a message passing interface, which greatly reduces the overall computation time for routine clinical practice. To test this approach, treatment for 10 patients with paranasal sinus cancer was planned using a total of 5 beams from a pool of 46 possible beam angles. The PMBAO treatment plans were also compared with IMRT plans designed using 9 equally spaced coplanar beams, which is the standard approach in our clinic. Plans with these two different beam configurations were compared with respect to dose conformity, dose heterogeneity, dose-volume histograms, and doses to organs at risk (i.e., eyes, optic nerve, optic chiasm, and brain). RESULTS: The noncoplanar beam configuration was superior in most paranasal sinus carcinoma cases. The target dose homogeneity was better using a PMBAO 5-beam configuration. However, the dose conformity using PMBAO was not improved and was case dependent. Compared with the 9-beam configuration, the PMBAO configuration significantly reduced the mean dose to the eyes and optic nerves and the maximum dose to the contralateral optical path (e.g. the contralateral eye and optic nerve). The maximum dose to the ipsilateral eye and optic nerve was also lower using the PMBAO configuration than using the 9-beam configuration, although this difference was not significant. The mean doses to the optic chiasm and brain are marginally lower using the PMBAO configuration than using 9-beam configuration. The maximum doses to the optic chiasm and brain are the same with the PMBAO configuration and the 9-beam configuration. CONCLUSION: Parallelized multiple-resolution beam angle optimization with an optimized noncoplanar beam configuration is an effective and practical approach for IMRT treatment planning. Five-beam treatment plans optimized using the PMBAO are at least equivalent to, and overall better than, the plans using 9 equally spaced coplanar beams.