HIV knowledge and condom intention among sexually abstinent Chinese students.

AIMS: To (a) assess the HIV/AIDS knowledge and sources of HIV/sexually transmitted infection (STI) information among sexually abstinent college students in China; (b) examine whether constructs from the transtheoretical model (TTM) are applicable to this study population regarding condom use intention; and (c) evaluate the association between genders and TTM constructs, and HIV/AIDS knowledge. BACKGROUND: Chinese college students are vulnerable to HIV and other STIs. Strategies targeting abstinent students are more cost-effective than providing treatment for diseases. METHODS: We surveyed 390 students enrolled in two universities in China. Data were collected from June 2009 to March 2010. RESULTS: Only 11% and 24% were aware of HIV spread by infected semen and of the protective effects of condom use against HIV. The mass media were major sources of HIV/STI information. Individuals who had higher levels of self-efficacy and reported more perceived benefits and fewer perceived barriers were more likely to be in TTM contemplation stage of condom use than those in precontemplation. Females were less likely to discuss HIV/STIs through online chat or email with strangers than males. Individuals who had higher levels of self-efficacy and reported more perceived benefits and fewer perceived barriers were more likely to be in TTM contemplation stage of condom use than those in precontemplation. CONCLUSION: Sexually abstinent college students in China may be more likely to transition from precontemplation to contemplation if they know the benefits of condom use for the prevention of HIV/STIs and if they learn to successfully minimize potential barriers related to condom use.

Self-reported gastrointestinal disorders among veterans with gulf war illness with and without posttraumatic stress disorder.

BACKGROUND: Gulf War Illness (GWI) is a chronic, multi-symptom disorder affecting 25%-32% of Gulf War veterans. Veterans with GWI disproportionately suffer from gastrointestinal (GI) disorders. Given the increasing evidence supporting a gut-brain axis, we explore the relationship between post-traumatic stress disorder (PTSD), GWI, and self-reported GI disorders among GW veterans. METHODS: Veterans from the Gulf War Era Cohort and Biorepository responded to a mail-based survey (N = 1058). They were stratified by GWI (Centers for Disease Control definition) and PTSD status. This yielded three groups: GWI-, GWI+/PTSD-, and GWI+/PTSD+. Multivariable logistic regression adjusting for demographic and military characteristics examined associations between GWI/PTSD groups and GI disorders. Results were expressed as adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). KEY RESULTS: The most frequently reported GI disorders were irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), and colon polyps (CP). The GWI+/PTSD+ group had a higher odds of these disorders than the GWI+/PTSD- group (aORIBS  = 3.12, 95% CI: 1.93-5.05; aORGERD  = 2.04, 95% CI: 1.44-2.90; aORCP  = 1.85, 95% CI: 1.23-2.80), which had a higher odds of these disorders than the GWI- group (aORIBS  = 4.38, 95% CI: 1.55-12.36; aORGERD  = 2.51 95% CI: 1.63-3.87; aORCP  = 2.57, 95% CI: 1.53-4.32). CONCLUSIONS & INFERENCES: GW veterans with GWI and PTSD have significantly higher odds of specific self-reported GI disorders than the other groups. Given the known bidirectional influences of the gut and brain, these veterans may benefit from a holistic healthcare approach that considers biopsychosocial contributors to the assessment and management of disease.

Cell proliferation kinetics in human tumor xenografts measured with iododeoxyuridine labeling and flow cytometry: a study of heterogeneity and a comparison between different methods of calculation and other proliferation measurements.

The influence of overall treatment time in the results of fractionated radiation treatment was initially established in experimental tumors and, subsequently, in the clinic. The availability of techniques (antibodies against halogenated thymidine analogues and flow cytometry) which permit determinations of the duration of the synthesis phase, the labeling index, and the tumor potential doubling time (Tpot) in a short period of time and requiring only a small biopsy of tumor tissue, has expanded interest in the relationship between tumor cell proliferation and response to irradiation. A valuable tool in the study of this relationship are human tumor xenografts. Previous studies have shown a substantial intratumoral heterogeneity in the determinations of Tpot. Different methods of calculation of the kinetic parameters have been published. We have conducted a heterogeneity analysis and an evaluation of the different calculation methods in order to define the validity of Tpot as a proliferation rate measurement in human tumor xenografts. Results show the intertumoral variability in Tpot [between different types of human tumor xenografts systems (coefficient of variation = 88.2%)] to be greater than mean intratumoral variation (coefficient of variation = 30.8%); this suggests that this variation is potentially adequate to serve as a predictor of response. The diverse calculation methods provided significantly different absolute values but not different tumor ranking, probably because the time interval between labeling and sampling was maintained, for all the samples, between 6 and 8 h. Our study has found significant differences between the labeling index and the S-phase fraction determined with the DNA profile in 9 out of 10 tumor types. No correlation was found between the DNA index of the tumors in this series and their proliferation rate.

CDKN2/p16 or RB alterations occur in the majority of glioblastomas and are inversely correlated.

p16 is involved in a cell cycle regulatory cascade that includes cyclin-dependent kinase 4 (cdk4), cyclin D1, and pRb (retinoblastoma). Alterations of each of these components have been described in primary human glioblastoma multiforme (GBM) or in GBM cell lines. Because perturbation of any component in this pathway may have similar oncogenic effects, we studied the relationship between abnormalities of CDKN2/p16 and RB, the two commonly involved tumor suppressor genes, in 55 astrocytic gliomas (42 GBMs, 8 anaplastic astrocytomas, and 5 astrocytomas). By using comparative multiplex PCR, homozygous deletions of the CDKN2/p16 gene were detected in 24 GBMs (57%) and in 2 anaplastic astrocytomas. Two additional GBMs and one anaplastic astrocytoma had allelic loss of chromosome 9p, as assessed by microsatellite polymorphisms flanking the CDKN2/p16 region. Single-strand conformation polymorphism and DNA sequencing analysis of all three coding exons of CDKN2/p16 revealed a frameshift mutation (four-bp deletion) in one of the three GBMs that had lost the remaining 9p allele. Allelic loss of chromosome 13q at the RB gene, RB gene mutations, or loss of pRb expression was noted in 14 GBMs (33%) and 2 anaplastic astrocytomas. Thirty-six of 42 GBMs (86%) had alterations of either CDKN2/p16 (n = 22), RB (n = 10), or both (n = 4); these two genetic changes, however, were relatively exclusive (P = 0.003). Furthermore, of the six GBMs without either CDKN2/p16 or RB gene abnormalities, one case had CDK4 gene amplification. These data indicate that the vast majority of GBMs probably have inactivation of the p16-cdk4/cyclin D1-pRb pathway. The findings also provide corroborative evidence that CDKN2/p16 and RB are the critical glioma tumor suppressor genes on chromosomes 9p and 13q, respectively.

Long-term survival of rats harboring brain neoplasms treated with ganciclovir and a herpes simplex virus vector that retains an intact thymidine kinase gene.

Survival of rats harboring cerebral 9L gliosarcomas can be significantly extended by an intratumoral inoculation with a herpes simplex virus vector, designated as hrR3. This vector, which bears the lacZ reporter gene, is defective in the gene encoding ribonucleotide reductase, allowing for replication in dividing tumor cells but not in postmitotic neural cells. It also possesses an intact viral thymidine kinase (TK) gene, which confers chemosensitivity to ganciclovir. In this study, the ability of ganciclovir to potentiate the antitumor effect of hrR3 was evaluated. In culture, there was a 23% decrease in the growth of 9L cells treated with hrR3 plus ganciclovir compared to hrR3 alone (P < 0.01). The combination of hrR3 plus ganciclovir led to the long-term survival of 48% of rats harboring intracerebral 9L gliosarcomas compared to 20% survival in the hrR3 group (P < 0.05). Ganciclovir treatment had no effect on the growth of tumor cells in vitro or in vivo when a herpes simplex virus vector with a defective TK gene was used. Immunocytochemistry confirmed selective expression of the TK gene in cells within the tumor. These findings indicate that the TK gene can potentiate the antitumor effect of the hrR3 herpes simplex virus vector and provide the basis for placing additional therapeutic genes in the genome of hrR3.

Radiation in management of patients with dermatofibrosarcoma protuberans.

PURPOSE: The preferred treatment of dermatofibrosarcoma protuberans (DFSP) is wide resection, namely, margins > or = 3 cm beyond the evident disease and histologically negative margins. We assess the success achieved by radiation combined with surgery for positive/close margins or by radiation alone for those tumors that are not resectable for technical/medical reasons. The literature on this point is virtually nonexistent. MATERIALS AND METHODS: The outcome of treatment of 18 patients with DFSP by radiation alone (n = 3) and radiation and surgery (n = 15) at the Massachusetts General Hospital was assessed. All of the lesions at the time of the treatment by radiation alone or combined with surgery were less than 10 cm. This was the maximum dimension. The actual tumor volume was much less than indicated by this maximum dimension, as the tumors were usually relatively flat. RESULTS: The 10-year actuarial local control rate was determined to be 88%. Local control was realized in the three patients treated by radiation alone, with follow-up periods of > or = 9 years. Among 15 patients treated by radiation and surgery, there have been three local failures; the 10-year actuarial local control rate was 84%. The three local failures occurred in 12 patients whose surgical margins were positive. One of these three local failures developed in the group of two patients whose lesions were scored as grade II. CONCLUSION: Radiation in well-tolerated dose schedules is an effective option in the management of patients with DFSP. This appears to be true for radiation alone or postoperatively for margin-positive disease (primary or recurrent).

Proliferating cell nuclear antigen and mitotic activity in rectal cancer: predictor of response to preoperative irradiation.

PURPOSE: This study examines the association between the pathologic response of rectal cancer after irradiation and its pretreatment proliferative state as assayed by proliferating cell nuclear antigen (PCNA) and mitotic activity. PATIENTS AND METHODS: Ninety patients with clinical stage T3 and T4 rectal cancer received preoperative irradiation followed by surgery. Pretreatment tumor biopsies were scored for PCNA activity (number of tumor cells staining immunohistochemically with an anti-PCNA monoclonal antibody) and the number of mitoses per 10 high-powered fields (hpf). Postirradiation surgical specimens were examined for extent of residual disease. RESULTS: The tumors of 33 of 90 patients (37%) exhibited marked pathologic downstaging (no residual tumor or cancer confined to the rectal wall) after preoperative irradiation. Two features were independently associated with the likelihood of marked pathologic regression after preoperative irradiation: lesion size and PCNA/mitotic activity. When stratified by tumor size, marked tumor regression occurred most frequently in smaller tumors with high PCNA/mitotic activity compared with larger tumors with lower PCNA/mitotic activity. Intermediate downstaging rates were seen for small or large tumors with moderate PCNA/mitotic activity. CONCLUSION: Tumor PCNA/mitotic activity predicts the likelihood of response to irradiation, which may aid in formulating treatment policies for patients with rectal cancer.

Postoperative radiation therapy for high-risk colon carcinoma.

PURPOSE: This study examines the experience of patients treated with postoperative radiation therapy after resection of high-risk colon carcinoma in an effort to assess the potential role of this modality in combination with current systemic therapies. PATIENTS AND METHODS: From 1976 to 1989, 203 patients received postoperative radiation therapy with and without concurrent fluorouracil (5-FU) chemotherapy following resection of modified Astler-Coller B2, B3, C2, and C3 colon tumors. Of the 203 patients, 30 (15%) were identified as having residual local tumor after subtotal resection, whereas 173 (85%) had no known residual disease. The 173 patients treated with adjuvant radiation therapy were compared with a historical control group of 395 patients undergoing surgery only. RESULTS: Three groups of patients who appeared to benefit from postoperative radiation were identified. Improved local control and recurrence-free survival rates were seen for patients with stage B3 and C3 colon carcinoma treated with postoperative radiation therapy compared with a similarly staged group of patients undergoing surgery only. Irradiated patients whose tumors had an associated abscess or fistula formation had improved local control and recurrence-free survival rates compared with a similar group of patients undergoing surgery only. There appears to be a subset of patients with residual local disease after subtotal resection that may be salvaged by high-dose postoperative radiation therapy. CONCLUSION: Selected groups of patients with colon carcinoma may benefit from postoperative radiation in addition to current systemic therapies. Integration of 5-FU and levamisole with postoperative radiation therapy should be considered for patients with (1) stage B3 and C3 lesions, (2) tumors associated with abscess or fistula formation, and (3) residual local disease after subtotal resection.

Prognostic significance of proliferative indices in meningiomas.

The prognostic value of tumor proliferative indices in meningiomas was assessed by mitotic counts and by immunocytochemistry using a monoclonal antibody against the proliferating cell nuclear antigen (PCNA) (clone 19A2), a 36-kd nuclear protein involved in DNA synthesis. Sixty-three intracranial meningiomas were classified as benign (26), with atypical features (24) or as malignant (13). The patients included 24 men and 39 women, mean age 54.2 +/- 1.7 (mean +/- SEM) (range 15-78) at initial presentation. Twenty-four of the 63 primary tumors recurred locally, including 23.1% (6/26) of the benign, 37.5% (9/24) of the atypical, and 69.2% (9/13) of the malignant meningiomas. Among tumors that recurred, 1/9 (11%) of the atypical and 5/9 (55.5%) of the malignant tumors had had macroscopical total excision at the initial surgery. The mean interval to recurrence was 52 +/- 11.8 months. The mean progression-free follow-up period for patients without tumor recurrence was 82 +/- 8.5 months. Analysis of variance revealed that significant differences existed between tumor grades for both PCNA indices (1.16 +/- 0.29% for benign; 14.14 +/- 2.07% for atypical and 21.37 +/- 5.47% for malignant) and mitotic indices (total counts per ten high power fields) (0.08 +/- 0.05 for benign, 4.75 +/- 0.91 for atypical and 19.00 +/- 4.07 for malignant). Multivariate regression analysis indicated that mitotic index > 6 was the single most important factor (p < 0.05) for shorter disease-free interval. Age, sex and total surgical excision were not significant factors. PCNA index was a significant factor in the univariate model, but not in the multivariate model.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of MIB-1 (Ki-67) immunoreactivity in differentiating grade II and grade III gliomas.

The grading of glial tumors has traditionally relied on histological assessment, but the distinction between grade II and grade III gliomas is still a subject of debate. We examined the value of the monoclonal antibody MIB-1 (Ki-67) labeling index (LI) in the differentiation between grade II and grade III gliomas by either the 1993 WHO grading scheme or the St. Anne-Mayo grading scale. The MIB-1 Li in the most densely labeled areas from 80 diffuse cerebral hemispheric gliomas was determined. The tumors included 16 grade II, 31 grade III and 33 grade IV gliomas by the WHO scale. The mean LIs (%) were 0.88 +/- 0.29 for grade II, 8.75 +/- 1.71 for grade III, and 9.12 +/- 1.55 for grade IV gliomas. Analysis of variance indicated a significant difference in mean LIs between grades II and III and grades II and IV (p < or = 0.0001), but not between grades III and IV. Seven tumors were classified differently by the 2 systems (grade III by WHO, but grade 2 by St. Anne-Mayo), and all had MIB-1 LI over 3%. Univariate analysis showed that MIB-1 LI with a cut-off point at 1.5% was a significant prognostic factor (p < or = 0.0005). High tumor grade (WHO, p < or = 0.0002; St. Anne-Mayo, p < or = 0.0006) and patient age > 50 (p < or = 0.0001) were also significant factors for shorter survival. Using Cox Regression Multivariate Analysis, MIB-1 LI > 1.5% was a significant independent predictor of shorter disease survival when paired with tumor grade (p < or = 0.032), patient age (p < or = 0.0065), or gender (p < or = 0.0007). We conclude that the MIB-1 immunoreactivity is useful in distinguishing grade II from grade III gliomas, and maybe more sensitive in assigning aggressive gliomas to grade III than the St. Anne-Mayo grading system.

Chronic lymphocytic leukemia and the central nervous system: a clinical and pathological study.

Chronic lymphocytic leukemia is the most common human leukemia but infrequently causes neurologic symptoms. We have reviewed all previously reported cases of chronic lymphocytic leukemia in the CNS along with three new cases; one patient was diagnosed antemortem and treated with immediate improvement and 4-year survival. In addition, we reviewed all autopsy cases since 1972 and available lumbar puncture data on patients with chronic lymphocytic leukemia admitted to the Massachusetts General Hospital. Invasion of the CNS by chronic lymphocytic leukemia often leads to confusional state, meningitis with cranial nerve abnormalities, optic neuropathy, or cerebellar dysfunction. Lumbar puncture shows a lymphocytosis consisting of monoclonal B cells, but CSF cytology studies are of limited value in establishing the diagnosis. Long-term survival may be related to the stage of chronic lymphocytic leukemia at the time of CNS disease and may be associated with intrathecal chemotherapy. A mild, asymptomatic infiltration of the brain, frequently noted in late-stage chronic lymphocytic leukemia in autopsy series, may explain the CSF lymphocytosis in some patients with late-stage chronic lymphocytic leukemia.

Does prolonged treatment course adversely affect local control of carcinoma of the larynx?

PURPOSE: The purpose of this paper is to present local control rates of carcinoma of the larynx in relation to the total treatment course after radical radiation therapy. METHODS AND MATERIALS: A total of 1350 patients with laryngeal carcinoma treated at the Massachusetts General Hospital for the past three decades were available for analysis. Treatment courses were divided into two groups: 45 days and > 45 days. The local control rates were compared and evaluated for statistical differences. RESULTS: The data indicated that prolonged treatment course adversely affects local tumor control of both advanced glottic and supraglottic lesions, but to a lesser degree for the early tumors. CONCLUSION: The study indicated that for optimal local control, radiation treatment should be completed as soon as possible, preferably within 6.5 weeks, either by once- or twice-daily accelerated programs. The local control of early T1 glottic cancer has been exceedingly satisfactory by conventional once-daily radiation therapy. Further improvement by shortening of treatment time for such early lesions will be difficult to assess without a prospective randomized trial.

Local control of T3 carcinomas after accelerated fractionation: a look at the "gap".

PURPOSE: To study the effects of midcourse treatment break or gaps related to the local control of T3 carcinoma of the oropharynx and larynx following accelerated hyperfractionated radiation therapy. METHODS AND MATERIALS: All patients were treated at the Massachusetts General Hospital from 1979 through 1994 with treatment consisting of 1.6 Gy per traction, two fractions a day for the treatment of T3 carcinoma of the oropharynx and larynx. They were entered in the head and neck data base. Their treatment dates, treatment breaks, and doses vs. local control were analyzed and compared. A p-value of 0.05 was considered statistically significant. RESULTS: A total of 162 patients were available for review. Due to the acute severe mucosal effects, most of the patients required a midcourse pause or "break" after a dose of 38.4-48 Gy before treatment could be resumed and completed. The data indicate that (a) prolongation of the treatment gap for more than 14 days, (b) total treatment course longer than 45 days, (c) total dose less than 67 Gy, and (d) male gender adversely affected local control. In spite of the gaps, the female patients with advanced carcinomas enjoyed the benefits of improved local control after the accelerated hyperfractionated radiation therapy. CONCLUSIONS: Accelerated hyperfractionation radiation therapy using 1.6 Gy per fraction/twice-a-day (b.i.d.) for a total dose of 70.4 Gy in 6 weeks is effective in achieving high local control of T3 squamous cell carcinoma of the oropharynx and larynx. The midcourse treatment gap should be as short as possible with the projected total dose and time. Should the gaps be unduly prolonged due to various circumstances, further increase in the total dose, for example, 72-75 Gy, and/or increase of the fraction sizes, for example, 1.8-2.0 Gy/f b.i.d. after the gap may be necessary to compensate for the adverse effects of the tumor regeneration from the prolonged gap.

Radiation therapy for chordomas of the base of skull and cervical spine: patterns of failure and outcome after relapse.

PURPOSE: To determine the patterns of failure and outcome following relapse of chordomas of the base of skull and cervical spine. METHODS AND MATERIALS: Between November 1975 and October 1993, 204 patients were treated for chordoma of the base of skull or cervical spine, of which 63 have developed relapse. These 63 patients constitute the main focus of this study. Forty-five patients presented with base of skull and 18 with cervical spine tumors. All patients received combined proton and photon beam radiation. The median prescribed dose was 70.1 cobalt-Gray equivalent (CGE) (range 66.6-77.4). There were 25 males and 38 females, with a median age of 41 years (range 7-66). Median follow-up was 54 months (range 8-158). RESULTS: Sixty-three of the 204 patients treated (31%) had treatment failure. Among the 63 patients who relapsed, 60 (95%) experienced local recurrence, and in 49 patients (78%), this was the only site of failure. Two of 63 patients (3%) developed regional lymph node relapse and 3 of 63 (5%) developed surgical pathway recurrence (1 left neck, 1 palate and 1 nasal cavity). Thirteen of 204 patients relapsed in distant sites, accounting for 20% (13 of 63) of all patients with recurrence in this series. The most common metastatic sites were lungs and bones presenting in 7 of 13 and 6 of 13 patients, respectively. Only 2 of 13 patients failed with isolated distant metastasis. The actuarial 3- and 5-year survival rates after local relapse (60 patients) were 44 and 5%, respectively. Following distant failure (13 patients), the 3- and 5-year survival rates were 25 and 12%, respectively. After any relapse (63 patients) the corresponding survival rates were 43 and 7%. Following local relapse, 49 of 60 patients underwent salvage therapy consisting of subtotal resection in most patients (46 of 49). The remaining 11 of 60 patients received supportive care only. Salvage therapy resulted in stable or improved status without subsequent disease progression in 26 of 49 (53%), and progressive disease in 16 of 49 patients (33%). The actuarial 2- and 5-year overall survival rates following relapse for the 49 patients who underwent salvage treatment were 63 and 6%, which favorably compared to the 2-year survival rate of 21% for those who received supportive care only (p = 0.001). CONCLUSION: Local relapse is the predominant type of treatment failure for chordomas of the base of skull and cervical spine. Salvage treatment may relieve symptoms; however, most patients will ultimately succumb to their disease. Poor long-term survival rates following relapse emphasize the importance of a combined treatment approach with experienced surgeons and radiation oncologists at the time of primary treatment. For most patients, only permanent local tumor control will offer a chance of cure.

Base of skull and cervical spine chordomas in children treated by high-dose irradiation.

PURPOSE: To evaluate the outcome of children with base of skull or cervical spine chordomas treated by high dose irradiation. METHODS AND MATERIALS: Eighteen children, 4 to 18 years of age, with base of skull or cervical spine chordomas, received fractionated high-dose postoperative radiation using mixed photon and 160 MeV proton beams. The median tumor dose was 69 Cobalt Gray-equivalent (CGE) with a 1.8 CGE daily fraction. RESULTS: The median follow-up was 72 months. The 5-year actuarial survival was 68% and the 5-year disease-free survival (DFS) was 63%. The only significant prognostic factor was the location: patients with cervical spine chordomas had a worse survival than those with base of skull lesions (p = 0.008). The incidence of treatment-related morbidity was acceptable: two patients developed a growth hormone deficit corrected by hormone replacement, one temporal lobe necrosis, and one fibrosis of the temporalis muscle, improved by surgery. CONCLUSION: Chordomas in children behave similarly to those in adults: children can receive the same high-dose irradiation as adults with acceptable morbidity.

The effect of the overall treatment time of fractionated irradiation on the tumor control probability of a human soft tissue sarcoma xenograft in nude mice.

PURPOSE: To study the impact of the overall treatment time of fractionated irradiation on the tumor control probability (TCP) of a human soft tissue sarcoma xenograft growing in nude mice, as well as to compare the pretreatment potential doubling time (Tpot) of this tumor to the effective doubling time (Teff) derived from three different schedules of irradiation using the same total number of fractions with different overall treatment times. METHODS AND MATERIALS: The TCP was assessed using the TCD50 value (the 50% tumor control dose) as an end point. A total of 240 male nude mice, 7-8 weeks old were used in three experimental groups that received the same total number of fractions (30 fractions) with different overall treatment times. In group 1, the animals received three equal fractions/day for 10 consecutive days, in group 2 they received two equal fractions/day for 15 consecutive days, and in group 3 one fraction/day for 30 consecutive days. All irradiations were given under normal blood flow conditions to air breathing animals. The mean tumor diameter at the start of irradiation was 7-8 mm. The mean interfraction intervals were from 8-24 h. The Tpot was measured using Iododeoxyuridine (IudR) labeling and flow cytometry and was compared to Teff. RESULTS: The TCD50 values of the three different treatment schedules were 58.8 Gy, 63.2 Gy, and 75.6 Gy for groups 1, 2, and 3, respectively. This difference in TCD50 values was significant (p < 0.05) between groups 1 and 2 (30 fractions/10 days and 30 fractions/15 days) vs. group 3 (30 fractions/30 days). The loss in TCP due to the prolongation of the overall treatment time from 10 days to 30 days was found to be 1.35-1.4 Gy/day. The pretreatment Tpot (2.4 days) was longer than the calculated Teff in groups 2 and 3 (1.35 days). CONCLUSION: Our data show a significant loss in TCP with prolongation of the overall treatment time. This is most probably due to an accelerated repopulation of tumor clonogens. The pretreatment Tpot of this tumor model does not reflect the actual doubling of the clonogens in a protracted regimen.

Late rectal bleeding following combined X-ray and proton high dose irradiation for patients with stages T3-T4 prostate carcinoma.

PURPOSE: Dose escalation for prostate cancer by external beam irradiation is feasible by a 160 MeV perineal proton beam that reduces the volume of rectum irradiated. We correlated the total doses received to portions of the anterior rectum to study the possible relationship of the volume irradiated to the incidence of late rectal toxicity. METHODS: We have randomized 191 patients with stages T3 and T4 prostatic carcinoma to one of two treatment dose arms. These were: 1) 75.6 Cobalt-Gy-equivalent (CGE), 50.4 Gy delivered by 107-25 MV photons followed by 25.2 CGE delivered perineally by protons (Arm 1) or 2) 67.2 CGE delivered by 10-25 MV photons (Arm 2). RESULTS: With a median follow-up of 3.7 years, post-irradiation rectal bleeding (grades 1 and 2 only, none requiring surgery or hospitalization) from telangiectatic rectal mucosal vessels has occurred in 34% of 99 Arm-1 patients and 16% of 92 Arm-2 patients (p = 0.013). Dose-volume histograms (DVHs) for the anterior rectal wall, the posterior rectal wall and the total rectum in 41 patients treated on Arm 1 were calculated from the three dimensional dose distributions. Rectal bleeding has occurred in 14 or 34% of the 41 DVH-analyzed subset of Arm-1 patients. Both the fractional volume of the anterior rectum and the total dose received by fractional volumes of the anterior rectum significantly correlate with the actuarial probability of bleeding. CONCLUSIONS: Clinicians planning dose escalation to men with localized prostate cancer should approve with caution treatment plans raising more than 40% of the anterior rectum to more than 75 CGE without additional effort to protect the rectal mucosa because this late sequela data indicate that more than half of these men will otherwise have rectal bleeding.

Adult soft tissue sarcomas of the head and neck treated by radiation and surgery or radiation alone: patterns of failure and prognostic factors.

PURPOSE: To analyze our experience treating soft tissue sarcomas of the head and neck in adults, and to identify patterns of failure and prognostic factors. METHODS AND MATERIALS: The records of 57 patients with Stage M0 disease treated by radiation with or without surgery between 1972 and 1993 were reviewed. Median follow-up time was 4.3 years (range, 1.1-16.8 years). A group of potential prognostic factors was evaluated, including age at diagnosis, sex, initial tumor presentation (primary vs. recurrent), grade, T-stage, direct tumor extension, tumor depth, duration of treatment, and radiation dose. RESULTS: The subset of angiosarcomas (11 out of 57 patients) had a considerably adverse effect on treatment outcome for the total group of sarcomas, with actuarial 5-year overall survival (OS), locoregional control (LRC), and freedom from distant metastasis (FDM) rates being 31%, 24%, and 42%, respectively. In contrast, for the remaining 46 patients with other histopathological tumor types, OS, LRC, and FDM rates were significantly higher (74%, 69%, and 83%, respectively). For this group of patients, significant prognostic factors identified by uni- and multivariate analysis included tumor grade as a predictor of OS and T-stage as a predictor of LRC (p < or = 0.050). Those patients who experienced a locoregional recurrence were at a significantly increased risk of dying (p = 0.004 in a multivariate model). All 17 patients without direct tumor extension to neurovascular structures, bone, contiguous organs, or skin remained free from distant failure. In contrast, 27% of 29 patients with direct extension had developed distant metastases at 5 years. In multivariate analysis, the absence of direct extension was a positive predictor of FDM (p = 0.007) and of OS (p = 0.034). CONCLUSIONS: 1) Angiosarcomas of the head and neck have a considerably poorer prognosis than other soft tissue sarcomas of this site. 2) In addition to tumor grade and size, direct tumor extension may be a useful additional staging parameter. 3) High rates of locoregional failure in the head and neck area, a potential cause of morbidity and death, indicate a need for improved treatment strategies.

Brainstem tolerance to conformal radiotherapy of skull base tumors.

PURPOSE: The aim of this study was to analyze the long-term incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy. METHODS AND MATERIALS: Between 1974 and 1995, 367 patients with chordomas (n = 195) and chondrosarcomas (n = 172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. Following 3D treatment planning with delineation of target volumes and critical nontarget structures dose distributions and dose-volume histograms were calculated. Radiotherapy was given an 1.8 Gy or CGE (=Cobalt Gray Equivalent) dose per fraction, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to < or = 64 CGE and to the brainstem center to < or = 53 CGE. RESULTS: Follow-up time ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem toxicity was observed in 17 of 367 patients attributable to treatment, resulting in death of three patients. Actuarial rates of 5 and 10-year high-grade toxicity-free survival were 94 and 88%, respectively. Increased risk of brainstem toxicity was significantly associated with maximum dose to brainstem, volume of brainstem receiving > or = 50 CGE, > or = 55 CGE, and > or = 60 CGE, number of surgical procedures, and prevalence of diabetes or high blood pressure. Multivariate analysis identified three independent factors as important prognosticators: number of surgical procedures (p < 0.001), volume of the brainstem receiving 60 CGE (p < 0.001), and prevalence of diabetes (p < 0.01). CONCLUSIONS: Tolerance of brainstem to fractionated radiotherapy appears to be a steep function of tissue volume included in high dose regions rather than the maximum dose of brainstem alone. In addition, presence of predisposing factors as well as extent of surgical manipulation can significantly lower brainstem tolerance in the individual patient.

Temporal lobe (TL) damage following surgery and high-dose photon and proton irradiation in 96 patients affected by chordomas and chondrosarcomas of the base of the skull.

PURPOSE: To determine the temporal lobe (TL) damage rate in 96 patients treated with high-dose proton and photon irradiation for chordomas and chondrosarcomas of the base of the skull. METHODS AND MATERIALS: The records of 96 consecutive patients treated at Massachusetts General Hospital (MGH) and Harvard Cyclotron Laboratory (HCL) between June 1984 and 1993, for chordomas and chondrosarcomas of the base of the skull were reviewed. All the patients had undergone some degree of resection of the tumor prior to radiation therapy. Seventy-five patients were classified as "primary tumors" and 21 as recurrent or regrowing tumors after one or more surgical procedures. All the patients were randomized to receive 66.6 or 72 cobalt Gray equivalent (CGE) on a prospective dose-searching study by proton and photon irradiation (Radiation Therapy Oncology Group #85-26) with conventional fractionation (1.8 CGE/day, 5 fractions/week). All treatments were planned using the three-dimensional (3D) planning system developed at the Massachusetts General Hospital, and the dose was delivered using opposed lateral fields for the photon component and a noncoplanar isocentric technique for the proton component. Clinical symptoms of TL damage were classified into 4 grades. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans were evaluated for white matter changes. Abnormalities associated with persistent or recurrent tumor were distinguished from radiation-induced changes. TLs were delineated on the original scans of the 10 patients with damage and those of a group of 33 patients with no clinical or MRI evidence of injury. Dose distributions were calculated and dose-volume histograms were obtained for these patients. RESULTS: Of the patients, 10 developed TL damage, with bilateral injury in 2 and unilateral injury in 8. The cumulative TL damage incidence at 2 and 5 years was 7.6 and 13.2%, respectively. The MRI areas suggestive of TL damage were always separated from the tumor bed. Symptoms were severe to moderate in 8 patients. Several baseline factors, tumor- or host-related, were analyzed to evaluate their predictivity for TL damage: age, gender, tumor site, histology, type of presentation, type and number of surgical procedures, primary tumor volume, prescribed dose, normal tissue involvement, and volume of TL receiving doses ranging between 10 and 50 CGE or more. Only gender, in a univariate analysis (log rank) was a significant predictor of damage (0.0155), with male patients being at significantly higher risk of TL injury. In a stepwise Cox regression that included gender as a variable, no other baseline variable improved the prediction of damage. CONCLUSIONS: The 2- and 5-year cumulative TL damage rates were 7.6 and 13.2%, respectively. Despite the different TL damage rates related to age, tumor volume, number of surgical procedures prior to radiation therapy, and prescribed doses to the tumor, only gender was a significant predictor of damage (p = 0.0155) using a univariate (log rank) test. Chordomas and chondrosarcomas of the base of the skull may represent an interesting model to evaluate the TL damage rates because of their extradural origin, displacing the white matter instead of infiltrating it as gliomas do, because of their longer local recurrence-free survival other than gliomas and other brain tumors and because of the high doses of irradiation delivered to the target volume to obtain local control.