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Biomedical subjects

L B Harrison

Publications and source records attributed to L B Harrison.

At least 37 records · Page 2Linked to original sources
PubMed1998

The role of brachytherapy in head and neck cancer.

By precision dose delivery to a well-defined target, brachytherapy fulfills the complementary goals of delivering sufficient dose for tumor cell kill while sparing normal adjacent structures. The unique properties of this modality, either used alone or implemented in a combined modality setting with surgery or external-beam irradiation, offer an ideal means of enhancing the therapeutic ratio by exploiting the effect of local therapies while respecting normal tissue tolerance. Brachytherapy also provides an effective technique for the retreatment of patients with recurrent, persistent, or second primary head and neck malignant tumors in a previously irradiated region. The benefits of this treatment modality are reflected in excellent reported local control rates, shortened overall treatment times, reduced functional deficits, improved quality of life, and decreased costs. Successful brachytherapy relies, however, on close collaborative efforts between radiation oncologists and surgeons, careful assessment of the patient, precise planning, and technique that adheres to the rules of a system. Brachytherapy has been clearly identified as an effective, safe, and appealing modality in the treatment of head and neck malignancies.

Brachytherapy↗
PubMed1997

Long-term regional control after radiation therapy and neck dissection for base of tongue carcinoma.

PURPOSE: Minimal literature exists with 10-year data on neck control in advanced head and neck cancer. The purpose of this study is to determine long-term regional control for base of tongue carcinoma patients treated with primary radiation therapy plus neck dissection. METHODS AND MATERIALS: Between 1981-1996, primary radiation therapy was used to treat 68 patients with squamous cell carcinoma of the base of tongue. Neck dissection was added for those who presented with palpable lymph node metastases. The T-stage distribution was T1, 17; T2, 32; T3, 17; and T4, 2. The N-stage distribution was N0, 10; N1, 24; N2a, 6; N2b, 11, N2c, 8; N3, 7; and Nx, 2. Ages ranged from 35 to 77 (median 55 years) among the 59 males and nine females. Therapy generally consisted of initial external beam irradiation to the primary site (54 Gy) and neck (50 Gy). Clinically positive necks were boosted to 60 Gy with external beam irradiation. Three weeks later, the base of tongue was boosted with an Ir-192 interstitial implant (20-30 Gy). A neck dissection was done at the same anesthesia for those who presented with clinically positive necks, even if a complete clinical neck response was achieved with external beam irradiation. Neoadjuvant cisplatin-based chemotherapy was administered to nine patients who would have required a total laryngectomy if their primary tumors had been surgically managed. The median follow-up was 36 months with a range from 1 to 151 months. Eleven patients were followed for over 8 years. No patients were lost to follow-up. RESULTS: Actuarial 5- and 10-year neck control was 96% overall, 86% after radiation alone, and 100% after radiation plus neck dissection. Pathologically negative neck specimens were observed in 70% of necks dissected after external beam irradiation. The remaining 30% of dissected necks were pathologically positive. These specimens contained multiple positive nodes in 83% despite a 56% overall complete clinical neck response rate to irradiation. Regional failure occurred in only two patients, neither of whom underwent adjuvant neck dissection. Symptomatic neck fibrosis (RTOG grade 3) was not observed. Actuarial 5- and 10-year local control was 88% and 88%, disease-free survival was 80% and 67%, and overall survival was 86% and 52%. CONCLUSION: For base of tongue cancer, most patients can obtain long-term regional control with no severe complications after definitive radiation therapy, plus neck dissection for those who present with lymphadenopathy. Complete clinical regression of palpable neck metastases after irradiation poorly correlates with pathologic outcome. Our current policy is to include neck dissection at the time of implantation for patients who present with palpable neck metastases. We realize that this therapeutic approach may overtreat some patients, but we are reluctant to change our policy in light of these excellent outcomes.

Adult↗
PubMed1997

Detailed quality of life assessment in patients treated with primary radiotherapy for squamous cell cancer of the base of the tongue.

BACKGROUND: This study was conducted to evaluate quality of life in patients treated with primary radiotherapy (RT) for cancer of the base of tongue. METHODS: From 1981 to 1990, 36 patients with primary squamous cell cancer of the base of tongue were managed with primary radiotherapy. Ages ranged from 35 to 71 years (median, 58 years), T Stage was: T1, n = 11; T2, n = 14; T3, n = 10; T4, n = 1. Thirty-one patients (86%) had palpable cervical lymph node metastases at initial examination (N1, n = 16; N2, n = 11; N3, n = 4). Patients received external beam RT to their primary site and necks, followed by a brachytherapy boost to the tongue. Those with neck nodes also had a neck dissection. The median follow-up is 5 years (minimum, 3 years). Actuarial 5-year local control was 85%; regional control was 96%; distant metastases-free survival was 87.5%; and overall survival, 85%. Twenty-nine of the 30 long-term survivors completed (1) Memorial Symptom Assessment Scale (MSAS), (2) Functional Assessment of Cancer Therapy (FACT), (3) Performance Status Scale for Head and Neck Cancer (PSS), and (4) a sociodemographic and economic questionnaire. At the time of cancer diagnosis, 62% were employed full-time, and 21% were employed part-time; 83% were earning > $20,000/year, and 59% were earning > $60,000/year. RESULTS: At follow-up, annual incomes were similar to those at initial examination. Of those who had been working full-time, 72% were still in full-time work, and of those who had been working part-time, 83% were still in part-time work. Average PSS scores were 90 for eating in public, 96 for understandability of speech, and 68 for normalcy of diet. On the MSAS, the following symptoms had prevalence: > 30% xerostomia, difficulty swallowing, decreased energy, pain, worrying, insomnia, cough, drowsy, change in taste, and irritability. Scores on the FACT exceeded published values collected for a mixed cancer population. CONCLUSIONS: The overwhelming majority of patients achieved excellent functional status and quality of life and could maintain their prediagnosis earning potential and employment status after primary radiation for advanced base of tongue cancer.

Actuarial Analysis↗
PubMed1997

Extended anterior craniofacial resection for intracranial extension of malignant tumors.

OBJECTIVE: To review our experience with anterior craniofacial resection for malignant neoplasms with intracranial extension. Survival was analyzed in terms of presence of intracranial extension, extent of intradural disease, tumor histology, and histological status of margins. PATIENTS: In a retrospective review made at a tertiary cancer facility, 26 of the 115 consecutive patients undergoing craniofacial resection for malignant lesions of the anterior skull base had intracranial extension, defined as dural and/or brain extension. Survival was evaluated with the Kaplan-Meier product limit method, and comparisons between individual subgroups were performed using the log-rank test. RESULTS: Patients with intradural extension have a statistically worse disease-specific survival than patients without intracranial extension (P = 0.05). Surgical margins and tumor histology impact on survival. The incidence of local complications was 42% and of systemic complications, 8%. CONCLUSION: Anterior craniofacial resection is indicated for patients with resectable disease. The complication rate is comparable with that of patients without intracranial extension. Gross total resection with histologically negative margins portends a better prognosis. Esthesioneuroblastoma has a better prognosis than other tumor types.

Brain Neoplasms↗
PubMed1997

Combined surgery and radiation therapy for squamous cell carcinoma of the hypopharynx.

Squamous cell carcinoma of the hypopharynx remains a highly lethal disease. This article documents our experience with 132 patients undergoing surgical management of squamous cell carcinoma of the hypopharynx, of whom 80% received postoperative radiation therapy. Local-regional control was obtained in 61% of the patients. Five-year overall and disease-free survival rates were 30% and 41%, respectively. Prognosis was better in patients with limited disease: local disease permitting larynx-sparing surgery, N0/N1 clinical neck, and stage I/II/III disease. Cancer of the hypopharynx remains an aggressive entity associated with poor prognosis. Novel strategies stressing improved local-regional control with prevention of distant metastasis are warranted.

Adult↗
PubMed1997

Vocal fundamental frequency measures as a reflection of tumor response to chemotherapy in patients with advanced laryngeal cancer.

The fundamental frequency (F0) characteristics of 19 male patients with advanced laryngeal cancer, treated with cisplatin-based chemotherapy as part of a Larynx Preservation Protocol (LPP), were measured before each of three cycles of chemotherapy received before definitive radiotherapy (RT). In these select patients, for whom chemotherapy resulted in > or = 50% decrease in the tumor bulk, it was found that mean F0 was essentially unaffected by the disease and did not change over the course of chemotherapy, although the cycle of their treatment could be differentiated by both speaking F0 variability (pitch sigma) and F0 perturbation (jitter). Although these measures failed to distinguish between those patients showing a complete response (CR) (no measurable disease) versus a partial (PR) (residual) tumor response at the primary disease site, the significant changes observed in both groups indicate that frequency variation measures could prove valuable in the documentation of tumor response to nonsurgical therapeutic intervention if the voice is directly affected. Additional assessment of 15 age- and disease-matched patients who showed minimal or no primary response to the chemotherapy showed no significant change in any of the frequency measures after one chemotherapy cycle, suggesting that vocal improvement seen in the successful chemotherapy patients was not due to postbiopsy healing or other systemic influence unassociated with tumor reduction.

Carcinoma, Squamous Cell↗
PubMed1997

The role of chemotherapy in the curative treatment of head and neck cancer.

Historically, the application of chemotherapy in patients with squamous cell head and neck cancer had been limited to the palliative setting; however, the role of chemotherapy in the definitive management of these tumors has undergone great evolution during the last 5 to 10 years. Available randomized data currently support a role for chemotherapy as part of combined modality, curative treatment strategies in the management of patients with unresectable disease, advanced nasopharynx cancer, and as part of a larynx preservation approach in patients with advanced larynx or hypopharynx cancer requiring total laryngectomy. Chemoprevention as a strategy to prevent second primary tumors also shows great promise.

Antineoplastic Agents↗
PubMed1997

Intraoperative irradiation: current and future status.

Intraoperative radiation therapy (IORT) in its broadest sense refers to the delivery of irradiation at the time of an operation. This article will discusses the rationale for and results of both intraoperative electron radiation therapy and intraoperative high dose rate brachytherapy when used in conjunction with surgical exploration and resection and external beam radiation therapy and chemotherapy. Both IORT methods evolved with similar philosophies as an attempt to achieve higher effective doses of irradiation while dose limiting structures are surgically displaced.

Brachytherapy↗
PubMed1996

The effect of combined external beam radiotherapy and brachytherapy on local control and wound complications in patients with high-grade soft tissue sarcomas of the extremity with positive microscopic margin.

PURPOSE: A previously reported randomized trial from out institution demonstrated a local control advantage to adjuvant brachytherapy (BRT) for completely resected high grade soft tissue sarcoma (STS). In recent years, BRT boost has been combined with wide field external beam radiotherapy (EBRT) for selected patients in whom the margin(s) of resection was positive. This study evaluates the impact of BRT boost plus EBRT on local control in this subset of patients and on wound complication rates. METHODS AND MATERIALS: Between January, 1987 and December, 1992, 105 adult patients with primary or locally recurrent high grade STS of the extremity were treated with wide local excision and BRT alone (87 patients; dose: 45 Gy) or BRT plus EBRT (18 patients; dose: 15-20 Gy BRT + 45-50 Gy EBRT). The margin(s) of resection was positive in 10 out of 18 patients in the BRT + EBRT group vs. 17 out of 87 patients in the BRT alone group. Wound complications were classified as major if they required further operative intervention; moderate if there was purulent discharge, hematoma > 25 ml, wound separation > 2 cm, and persistent seroma requiring drainage; or minor if less than moderate. Median follow-up was 22 months. RESULTS: The overall 2-year actuarial local control rate was 86%. There was no difference in the 2-year actuarial local control rate between the BRT + EBRT group (90%) and the BRT alone group (82%) (9 = 0.32). However, for patients with positive resection margins the use of BRT + EBRT produced better local control than BRT alone [9 out of 10 (90%) vs. 10 out of 17 (59%)]. This difference approached but did not reach statistical significance (p = 0.08). No difference was seen in patients with negative margins. There was no significant difference in the overall wound complication rate (26% BRT vs. 38% BRT + EBRT, p = 0.31) nor in the combined major and moderate wound complication rate (16% BRT vs. 27% BRT + EBRT, p = 0.39). CONCLUSION: Our preliminary data suggest a trend in favor of BRT boost + EBRT as the optimal adjuvant local strategy for STS with positive resection margins. There is no significant difference in the wound complication rate with either technique.

Adolescent↗
PubMed1996

Feasibility study of the treatment of primary unresectable carcinoma of the pancreas with 103Pd brachytherapy.

PURPOSE: The purpose of this study was to assess the feasibility of 103Pd brachytherapy in the management of primary unresectable carcinoma of the pancreas. METHODS AND MATERIALS: Between August 1988 and January 1992, 11 patients with biopsy-proven primary unresectable adenocarcinoma of the pancreas were treated with 103Pd brachytherapy during laparotomy. The median age was 66 (range 57-70). The most common presenting symptoms were weight loss (eight patients), pain (six patients), and nausea/vomiting (four patients). Less common symptoms were jaundice (two patients), early satiety (two patients), and ascites (one patient). All patients underwent laparotomy and surgical staging. Eight patients had T3N0M0 disease, two patients had T3N1M0 disease, and one patient had T3N1M1 disease. The surgical procedure performed was biliary bypass in six patients, biopsy only in four patients, and gastric bypass in one patient. The average tumor dimension was 4.0 cm. The median activity, matched peripheral dose (MPD) and implanted volumes were 95.3 mCi, 124.4 Gy, and 33 cm3, respectively. The median initial dose rate was 0.21 Gy per hour. Five patients received postoperative external beam radiation therapy (median 45 Gy) and seven patients received chemotherapy postoperatively. The median follow-up was 7 months (range 1-19). RESULTS: The median survival for the entire group of patients was 6.9 months. Ten of 11 patients have died, with 1 patient presently alive and receiving chemotherapy for metastatic disease to the liver, but without local progression radiographically. Five of 11 patients (45%) were locally controlled, defined as either a complete response or freedom from progression at the site of the implant as evaluated by computed tomography scan. In the other six patients, the median time to local progression was 6.9 months. Five patients developed distant metastases (four liver, one subcutaneous nodule). Two patients failed in regional sites (one omentum, one paraaortic lymph node). Four of 11 patients (36%) developed acute postoperative complications that included one gastric outlet obstruction, one duodenal perforation, and two with sepsis. One of 11 patients (9%) developed a late complication of radiation enteritis 5 months after implantation. The median survival for patients experiencing complications was 1.7 months as compared to 8.4 months for the patients who did not develop a complication (p = 0.10). Pain relief was obtained in five out of six (83%) of the patients presenting with pain for a median duration of 24 weeks. Local control did not appear to be related to the MPD, dose rate, implanted volume, treatment with external beam irradiation, or the use of chemotherapy. Patients were more likely to develop a complication if the MPD was greater than 115 Gy (four out of six patients) as compared to those whose MPD was less than 115 Gy (one out of five patients) (p = 0.12). CONCLUSIONS: Because there was no improvement in median survival over conventional modalities, and the complication rate was high; we do not recommend 103Pd brachytherapy as a component of the treatment of unresectable adenocarcinoma of the pancreas.

Aged↗
PubMed1996

Preliminary results of phase I/II study of high-dose-rate intraoperative radiation therapy for pediatric tumors.

Ten children with locally advanced or recurrent tumors were treated on a Phase I/II study to assess the feasibility and toxicity of intraoperative radiotherapy (IORT) for primary and recurrent pediatric solid malignancies at high risk for local recurrence. Eligible patients include all primary and recurrent pediatric solid tumors that are amenable to resection and have residual microscopic or gross disease after surgery. In all cases, after a gross tumor resection was performed, a flexible, transparent, multichannel applicator was placed and secured within the tumor bed. Once the position of the applicator was optimized, the applicator catheters were attached to the cables of a high-dose-rate remote afterloader, and 1,200 cGy prescribed to 0.5-1.0 cm from the applicator was delivered to the tumor bed via the remote afterloader. One patient with a malignant teratoma developed a peri-rectal abscess 1 month after treatment; no other complications were noted. The 2-year actuarial local recurrence-free and distant metastases-free survival were 80% and 59%, respectively, with a median follow-up of 12 months (range: 3-18 months). The preliminary results suggest that high-dose-rate IORT is a safe and feasible modality for pediatric tumors at high risk for local recurrence. Longer follow-up will be needed to assess fully the toxicity and efficacy of this approach.

Adolescent↗
PubMed1996

Long-term subjective functional outcome of surgery plus postoperative radiotheraphy for advanced stage oral cavity and oropharyngeal carcinoma.

BACKGROUND: Although long-term cures have been achieved for locally advanced squamous cell carcinomas of the head and neck, there is a paucity of information available regarding patients' perspectives of their functional outcome. PATIENTS AND METHODS: Thirty-five long-term survivors free of disease following surgery and postoperative radiotherapy for advanced cancers of the oral cavity and oropharynx were sent questionnaires to evaluate their long-term functional outcome after therapy. The questionnaires included a subjective performance status scale that assessed the patient perceived (1) ability to eat in public, (2) understandability of speech, and (3) normalcy of diet. Twenty-nine of 35 patients participated in this function assessment and are the subjects of this report. RESULTS: The mean function scores for all patients were as follows: 72 for eating in public, 69 for understandability of speech, and 58 for normalcy of diet. Functional results were further analyzed by T stage and anatomic subsite. Inferior results were noted with increasing T stage. A two-way analysis of variance showed that this difference was significant even after adjusting for the effect of anatomic subsite (P = 0.0002, P = 0.018, and P = 0.0018 for the three outcome variables). In addition, patients with base of tongue lesions had a worse functional outcome for both early T state (T1/T2) and advanced T stage (T3/T4) when compared to other subsites. This difference averaged across T stage was statistically significant for understandability of speech (P = 0.0019) and normalcy of diet (P = 0.013), but was not significant for eating in public (P = 0.16). CONCLUSIONS: This performance status scale was found to be a useful tool for functional assessment following definitive therapy for advanced stage head and neck carcinomas. These subjective functional scores deteriorated with increasing T stage. In addition, functional scores for oral tongue, floor of mouth, and tonsillar primaries were superior to those for base of tongue lesions. These functional outcome scores are consistent with the extent of surgery required for the base of tongue subsite and are in direct relation to the patients' T stage in this study population.

Adult↗
PubMed1996

Long-term results of a prospective randomized trial of adjuvant brachytherapy in soft tissue sarcoma.

PURPOSE: This trial was performed to evaluate the impact of adjuvant brachytherapy on local and systemic recurrence rates in patients with soft tissue sarcoma. PATIENTS AND METHODS: In a single-institution prospective randomized trial, 164 patients were randomized intraoperatively to receive either adjuvant brachytherapy (BRT) or no further therapy (no BRT) after complete resection of soft tissue sarcomas of the extremity or superficial trunk. The adjuvant radiation was administered by iridium-192 implant, which delivered 42 to 45 Gy over 4 to 6 days. The two study groups had comparable distributions of patient and tumor factors, including age, sex, tumor site, tumor size, and histologic type and grade. RESULTS: With a median follow-up time of 76 months, the 5-year actuarial local control rates were 82% and 69% in the BRT and no BRT groups (P = .04), respectively. Patients with high-grade lesions had local control rates of 89% (BRT) and 66% (no BRT) (P = .0025). BRT had no impact on local control in patients with low-grade lesions (P = .49). The 5-year freedom-from-distant-recurrence rates were 83% and 76% in the BRT and no BRT groups (P = .60), respectively. Analysis by histologic grade did not demonstrate an impact of BRT on the development of distant metastasis, despite the improvement in local control noted in patients with high-grade lesions. The 5-year disease-specific survival rates for the BRT and no BRT groups were 84% and 81% (P = .65), respectively, with no impact of BRT regardless of tumor grade. CONCLUSION: Adjuvant brachytherapy improves local control after complete resection of soft tissue sarcomas. This improvement in local control is limited to patients with high-grade histopathology. The reduction in local recurrence in patients with high-grade lesions is not associated with a significant reduction in distant metastasis or improvement in disease-specific survival.

Brachytherapy↗
PubMed1995

Survey of brachytherapy practice in the United States: a report of the Clinical Research Committee of the American Endocurietherapy Society.

PURPOSE: To obtain reliable data on the extent of the brachytherapy practice in the United States by conducting a comprehensive survey of all facilities. METHODS AND MATERIALS: The Clinical Research Committee of the AES surveyed all 1321 radiation oncology facilities identified in the Patterns of Care Study (PCS) of the American College of Radiology (ACR). Multiple mailings and follow-up were made to obtain a high response rate. Survey responders and nonresponders were compared using chi-square tests. Summary statistics were reported. RESULTS: Of the 1321 facilities, 1054 responded (80%). Hospital-based and larger facilities had a statistically significant higher rate of response. Brachytherapy was being performed at 819 facilities (the median number of procedures = 21-50). Two hundred and two facilities did no brachytherapy. The common isotopes used were 137Cs (705 facilities), 192Ir (585 facilities), 125I (236 facilities), and 131I (194 facilities). The common brachytherapy techniques used were intracavitary (751 facilities), interstitial (536 facilities), intraluminal (310 facilities), and plaques (148 facilities). Remote afterloaded brachytherapy was used at 205 centers as follows: high dose rate (HDR) (164), medium dose rate (MDR) (5), and low dose rate (LDR) (36). Computerized dosimetry was most commonly used (790 facilities), followed by Patterson-Parker (104 facilities) and Quimby (72 facilities). The common sites treated were cervix (701 facilities), endometrium (565 facilities), head and neck (354 facilities), and lung (344 facilities). CONCLUSION: Data regarding brachytherapy practice has been obtained from a large percentage (80%) of all facilities in the United States. The majority (78-81%) of radiation oncology facilities perform brachytherapy; however, its use is restricted to gynecological implants in many of these centers. The results from this survey will be used to develop a pattern of care study and data registry in brachytherapy.

Brachytherapy↗
PubMed1995

Strategy for dose escalation using 3-dimensional conformal radiation therapy for lung cancer.

PURPOSE: Local failure is a major obstacle to the cure of locally advanced non-small-cell lung cancer. 3-Dimensional conformal radiation therapy (3-DCRT) selects optimal treatment parameters to increase dose to tumor and reduce normal tissue dose, potentially permitting dose escalation. There are several ongoing trials of dose escalation using 3-Dimensional conformal radiation therapy for non-small-cell lung cancer. We performed this analysis to determine if data derived from dose volume histograms could be used as the basis for designing the method of dose escalation in these trials. METHODS AND MATERIALS: Between 1990 and 1993, 31 patients were treated with 3-DCRT and had complete normal tissue dose volume histograms created as part of the planning process. The stage distribution was stage I/II 13%, stage IIIa in 45%, and stage IIIb in 42%. The median radiation dose to gross disease was 70.2 Gy (52.2-72 Gy). Elective mediastinal irradiation (50.4 Gy) was administered to 52% (16/31) of patients. RESULTS: The major toxicity encountered in this experience was pulmonary. Dose-volume-histogram data were used to analyze the predictors of toxicity and showed a correlation between risk of pulmonary toxicity and indices of dose to lung parenchyma. Grade 3 or higher pulmonary toxicity occurred in 38% (3/8) of pts with >30%of lung volume receiving > or =25 Gy, versus 4% (1/23) of pts. with < or = 30% lung receiving > or = 25 Gy (p=0.04). Grade 3 or higher pulmonary toxicity occurred in 29% (4/14) of patients with a predicted pulmonary normal tissue complication probability of 12% or higher versus 0% (0/17) in patients with a predicted probability of less than 12% (p=0.03). The single fatality occurred in a patient with a calculated pneumonitis probability of 85% and a high percent (49%) lung volume receiving >= 25 GY. CONCLUSION: This preliminary experience demonstrates a correlation between lung dose-volume-histogram data and the risk of severe pulmonary toxicity. This provides an opportunity to modify the method of radiation dose escalation. Dose-volume-histogram data can allow escalation according to the risk to the lung parenchyma (which is the major organ of concern) rather than escalation according to tumor dose levels. Because of teh major inter-patient variability of intrathoracic tumor bulk and anatomic distribution, this strategy is intuitively appropriate. This approach may facilitate completion of dose escalation studies and identification of maximum tolerable pulmonary dose levels.

Adult↗
PubMed1995

Controlled mold geometry for surgical deficit treatment planning.

The relatively precise placement of brachytherapy sources afforded by stereotactic frames for brain implants is not generally achievable for other sites, which lack the fixed geometry of the cranium and its contents. An exception is a source-containing rigid mold that delivers brachytherapy when inserted securely in a surgical defect. A technique has been developed in which an acrylic mold of the region to be treated is suspended in a demountable aluminum box, which is then filled to a suitable level with dental stone to form a casting that supports the mold and that can be removed intact. First, the box is aligned on a mill table and a ball mill is used to drill three parallel holes in the acrylic mold, with precisely known locations and depths and as widely separated as possible. The spherical air cavities that result from plugging these holes with ball-milled acrylic rods become reference markers in subsequent computed tomography (CT) scans. After optimum CT-coordinate locations have been planned for 125I seeds in catheters, they are transformed to mill coordinates using a matrix developed from the known marker coordinates in the two systems. Catheter holes are then drilled with the mold in the reassembled casting and box. The method has been used to treat both recurrent maxillary cancer and recurrent orbital rhabdomyosarcoma.

Biophysical Phenomena↗
PubMed1995

Salvage laryngectomy for unsuccessful larynx preservation therapy.

From 1983 to 1991, 31 patients underwent salvage laryngectomy for persistent or recurrent squamous carcinoma of the larynx (14), hypopharynx (15), or oropharynx (2) as part of a larynx preservation protocol. Laryngectomy was performed as a consequence of poor response to induction chemotherapy in 13 and for recurrent disease after completion of chemotherapy and irradiation in 18. Postoperative pharyngocutaneous fistula occurred in 39%, resulting in prolonged hospitalization. Local control was achieved in 68%, more often in patients with laryngeal as opposed to nonlaryngeal primaries (86% versus 53%; p = .05). The overall actuarial survival and disease-specific survival at 2 years were 32% and 38%, respectively. Disease-specific survival at 2 years was better in patients with laryngeal as compared to nonlaryngeal primaries (56% versus 24%; p = .02). There were no long-term survivors among the nonlaryngeal primary patients. In selected patients in whom larynx preservation failed, salvage laryngectomy was associated with acceptable local control and survival. Palliation was obtained in patients who were not cured by their laryngectomy. Future investigation will focus on identification of factors predicting complications and strategies to reduce the incidence and severity.

Antineoplastic Combined Chemotherapy Protocols↗