Hyperfractionation in the radiation therapy of unresectable non-oat cell carcinoma of the lung: preliminary report of a RTOG Pilot Study

Combined modality therapy for stage III non-small cell lung cancer

Lung cancer remains the leading cause of cancer death in the U.S. among both men and women. Approximately 45% of patients present with stage III disease. A proportion of these patients is amenable to surgical resection; however, the majority are "unresectable." For patients with unresectable stage IIIA/B disease, thoracic radiation therapy (TRT) was considered the standard of care until the late 1980s despite a very poor 5-year survival rate. Several clinical trials demonstrated that the combination of chemotherapy and TRT was superior to TRT alone. Based on these data, combined modality therapy became the standard of care for patients with good performance status. Recent trials have shown that concurrent chemoradiotherapy offers a significant survival advantage over sequential chemoradiotherapy. Despite a substantial number of clinical trials, important questions on the optimal treatment paradigm remain. The most effective chemotherapy combination, the use of induction or consolidation chemotherapy in addition to the concurrent portion of therapy, and the optimal dose of chemotherapy with concurrent TRT have yet to be determined. The optimal total dose, fractionation, acceleration, treatment volume, and tumor targeting remain questions related to the TRT portion of therapy. Although significant progress has been made, the majority of patients experience locoregional or distant progression of their disease and die within 5 years of diagnosis. Thus, continued development and participation in clinical trials is crucial to further improvements in the treatment of patients with stage III disease.

Twice daily irradiation increases locoregional control in patients with medically inoperable or surgically unresectable stage II-IIIB non-small-cell lung cancer

PURPOSE

To evaluate the effect of q.d. or b.i.d. radiotherapy (RT) on the outcome of patients with locally advanced non-small-cell lung cancer.

METHODS AND MATERIALS

We retrospectively reviewed the outcome of 261 patients with medically inoperable or surgically unresectable Stage II-IIIB non-small-cell lung cancer, who were treated with combined modality cisplatin-based chemotherapy and RT. Chemotherapy was administered either sequentially or concurrently with thoracic RT. The median follow-up was 18 months (range 2-92). Treatment groups included sequential chemotherapy and q.d. RT (n = 109), concurrent chemotherapy and q.d. RT (n = 48), and concurrent chemotherapy and b.i.d. RT (n = 104). Of the 261 patients, 97% had a Karnofsky performance score > or =80, and 86.2% had < or =5% weight loss in the 3 months before diagnosis; 66.7% had nonsquamous cell histologic features. All but 8 patients had Stage IIIA-B disease.

RESULTS

The 2- and 5-year locoregional control rate was 42.4% and 25.7% for the q.d. group and 70.6% and 45.8% for the b.i.d. group, respectively (p = 0.0001). The 2- and 5-year disease-free survival rate was 26.7% and 6.5% for the q.d. group and 39.6% and 27.3% for the b.i.d. group, respectively (p = 0.0114). The corresponding overall survival rates were 35.9% and 9.4% for the q.d. group and 38.7% and 26.1% for the b.i.d. group. No difference was found in the rate of distant metastasis between the 2 groups. Multivariate analysis indicated that b.i.d. RT was a favorable prognostic factor for locoregional control and disease-free survival.

CONCLUSION

RT b.i.d. significantly improved locoregional control and disease-free survival compared with RT q.d. in patients with Stage IIIA-B non-small-cell lung cancer.

The role of radiotherapy in non-small cell lung cancer

Most patients who receive a diagnosis of non-small cell lung cancer (NSCLC) have advanced disease and are not curable with surgery. Developments in the technology of radiation therapy (RT) have contributed to the broad utility of this treatment modality in both a curative and palliative capacity. Many patients at all stages, including those who are medically inoperable, may benefit from RT. Locally advanced NSCLC is treated commonly with combined modality therapy. Novel RT administration schedules and chemotherapy regimens for combined modality therapy are essential for improving the management of NSCLC. Additional benefits can be foreseen as new strategies for patient selection emerge.

Hyperfractionation: where do we stand?

Hyperfractionation is generally expected to allow an escalation of total dose, thereby increasing tumour control rate, without increasing the risk of late complications. The purpose of this review is to assess the empirical evidence for this therapeutic gain from hyperfractionated radiotherapy. Although extensive clinical data have been accumulated until now, especially on treatment of head and neck cancer, the line of evidence is not consistent. The present analysis indicates that the dose per fraction generally used in standard radiotherapy is already a good choice.

Hyperfractionated external radiation therapy in stage IIIB carcinoma of uterine cervix: a prospective pilot study

PURPOSE

Brazil has one of the highest incidence of carcinoma of the cervix in the world. Half of the patients have advanced stages at the diagnosis. Due to this large number of patients we decided to conduct a prospective pilot study to investigate the tolerance to and survival rate with hyperfractionated external radiotherapy only in patients with Stage IIIB carcinoma of the uterine cervix.

METHODS AND MATERIALS

Between January 1991 and December 1993, 23 patients underwent hyperfractionated external beam radiotherapy without brachytherapy. All cases were biopsy proven squamous cell carcinoma of cervix clinically Staged as IIIB (FIGO). Hyperfractionation (HFX) was given with 1.2 Gy doses, twice daily at 6-h interval, 5 days/week, to the whole pelvis up to 72 Gy within 30 working days. Complications were evaluated by an adaptation ot the RTOG Radiation Morbidity Scoring Table graded as 1 = none/mild; 2 = moderate, and 3 = severe.

RESULTS

Follow-up ranged from 27 to 50 months (median 40 months) on the 9 to 23 living patients at the time of the analysis in December 1995. There was no severe acute toxicity, but moderate acute reaction was high: 74%. The commonest site of complication was the intestine where severe late toxicity occurred in 2 of 23 (9%). Overall survival rate at 27 months was 48% and at 40 months was 43%.

DISCUSSION

There is little information in literature about HFX in carcinoma of the cervix. This is the third published study about it and the one that gave the highest total dose with external HFX of 60 x 1.2 Gy = 72 Gy. Theoretically, through the linear quadratic formula this schedule of HFX would be equivalent to 30 x 2 Gy = 60 Gy of standard fractionation, both treatments given in 30 working days. HFX schedules must be tested to establish their safety. Present results suggest being possible to further increase the total dose in the pelvis with hyperfractionated irradiation.

The evolution of Radiation Therapy Oncology Group (RTOG) protocols for nonsmall cell lung cancer

Over the past 2 decades, the Radiation Therapy Oncology Group (RTOG) has played a significant role in clarifying the role of radiation therapy (RT) in the treatment of nonsmall cell lung cancer (NSCLC). RTOG lung cancer research has evolved over this time period through a systematic succession of investigations. For unresectable NSCLC, the dependence of local tumor control and survival on total dose of standard fractionation RT, as well as pretreatment performance characteristics, was demonstrated in initial RTOG trials. Subsequently, further radiation dose intensification was tested using altered fractionation RT to total doses up to 32% higher than standard RT to 60 Gy, given as either hyperfractionation or accelerated fractionation, while attempting to retain acceptable normal tissue toxicity. These higher doses required rethinking of established RT techniques and limitations, as well as careful surveillance of acute and late toxicity. A survival advantage was shown for hyperfractionation to 69.6 Gy, in favorable performance patients, compared to 60 Gy. Further testing of high dose standard RT will use three-dimensional, conformal techniques to minimize toxicity. RTOG further extended the theme of treatment intensification for unresectable NSCLC by evaluating combined chemotherapy (CT) and RT. Improved local control and survival was shown for induction CT followed by standard RT to 60 Gy, compared to standard RT (60 Gy) and altered fractionation RT (69.6 Gy). The intent of current studies is to optimize dose and scheduling of combined CT and standard RT, as well as combined CT and altered fractionation RT. Noncytotoxic RT adjuvants, such as hypoxic cell sensitizers, nonspecific immune stimulants, and biologic response modifiers have also been studied. Resectable NSCLC has also been an RTOG focus, with studies of preoperative and postoperative RT, CT, and CT/RT, including the prognostic value of serum and tissue factors. RTOG studies have yielded incremental improvements in treatment outcome for NSCLC, better understanding of the disease dynamics, and a strong foundation for future investigations.

Survival analysis of untreated patients with non-small-cell lung cancer

The survival rate analysis of 130 patients with non-small-cell lung cancer who did not receive any specific anticancer therapy showed no statistically significant differences in the survival rates between various TNM combinations classified into stage groups II, IIIa, IIIb, and IV, as proposed by Mountain in 1989 and adopted by the American Joint Committee on Cancer. Following these findings, based on survival probabilities, two distinctive staging groups could be distinguished. The first stage group was composed of only the T1, 2N0, M0 combination, and the second of all other TNM combinations. In a purely biologic sense of tumor growth, the lymph node involvement appeared to be the crucial factor determining the length of survival.

Analysis of early and late deaths on RTOG non-small cell carcinoma of the lung trials: comparison with CALGB 8433

In a major study that showed a treatment advantage for induction chemotherapy followed by radiation therapy (CALGB 8433), there was a significantly (P = 0.02) lower proportion of patients dying within 105 days of registration in the chemotherapy/radiation arm than the radiation therapy arm; without this difference, the overall survival was marginally better (P = 0.059) for the chemotherapy/radiation group. A retrospective analysis of RTOG trials sought explanations for the phenomenon.

MATERIALS AND METHODS

Patients who fit the CALGB eligibility criteria and received radiation therapy alone in four prospective trials of the RTOG conducted between 1983 and 1989 were analyzed to determine factors that distinguished patients dying within 105 days from longer survivors. Two were trials of altered fractionation and two used standard fractionation. Of 683 patients identified, 107 (15.7%) died within 105 days after registration. The log linear model was used to evaluate relationships between death within 105 days and known prognostic factors. Karnofsky performance status (KPS), < 90 vs. > or = 90, was the only factor significantly related to death within 105 days (P = 0.0052). A Cox model with the same factors plus fractionation and total dose found KPS and T-stage associated with overall survival (P = 0.0005 and 0.025, respectively). The choice of the hyperfractionation arm (HFX) for Phase III study (69.6 Gy at 1.2 Gy b.i.d.) was based in part on comparison with standard fractionation (STD) from a concurrent RTOG protocol, 8321. Review of early deaths showed that this HFX arm had a lower proportion of patients dying within 105 days (7.9%) than STD in 8321 (21.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

A phase I/II study to evaluate accelerated fractionation via concomitant boost for squamous, adeno, and large cell carcinoma of the lung: report of Radiation Therapy Oncology Group 84-07

PURPOSE

A Phase I/II trial was conducted by the Radiation Therapy Oncology Group from 1984 to 1989 for 355 evaluable patients with non-small-cell lung cancer to assess tolerance to and efficacy of accelerated fractionation irradiation via concomitant boost.

METHODS AND MATERIALS

"Large" fields (primary tumor and locoregional lymph nodes) received 1.8 Gy followed after 4 to 6 hr by 1.8 Gy two to three times weekly to reduced "boost" fields (primary and involved nodes only). The total doses escalated during the study and started with 63 Gy in 5 weeks (45 Gy "large" field and 18 Gy "boost") for 61 patients. After follow-up for ongoing toxicity assessment, the total dose was increased to 70.2 Gy in 5.5 weeks (50.4 Gy "large" field and 19.8 Gy "boost") for the next 180 patients. The last 114 patients received 70.2 Gy in 5 weeks (45 Gy "large" field and 25.2 Gy "boost").

RESULTS

Pretreatment patient characteristics were well balanced between the three treatment arms. Grade 3 acute toxicity was 7% for the 63 Gy arm; it was 14% and 17% for the two 70 Gy arms. Grade 4 or greater acute toxicities (esophagitis and pneumonitis) were 2 to 3% for all three arms. Late toxicities ranged between 5 and 9% (> or = Grade 3) and 0 to 2% (> or = Grade 4), not statistically different among the three arms. There was no difference between the three regimens in median survival (9 months) or 1-year survival (39 to 44%). However, the 2-year survivals ranged from 16% (63 Gy) to 21% ("shortened" 70.2 Gy). Among 176 patients who had the same criteria as Cancer and Leukemia Group B protocol 84-33 (American Joint Committee on Cancer Staging, 1984, Stage III; Karnofsky performance status 70 to 100; < 6% weight loss), the 2-year survival rates ranged from 18 to 22%.

CONCLUSION

Concomitant boost accelerated fractionation irradiation regimens for non-small cell lung cancer may offer improved long-term survival without enhanced late toxicity. While acute toxicity is somewhat increased, further refinement of the relationship of "large" to "boost" field doses may improve the therapeutic ratio. Further Phase I/II testing seems justified and necessary, before concomitant boost accelerated fractionation irradiation is tested in Phase III trials for NSCLC.

Low-versus high-energy photon beams in radiotherapy for lung cancer

This retrospective study analyzed the outcome of lung cancer patients who were treated with either 4-MV or 10-MV photons. From October 1979 through December 1982, 126 patients with locally advanced, unresectable or medically inoperable, nonmetastatic non-small cell lung cancer were treated in a prospective trial in which they were randomly assigned to one of three chemotherapy combinations and thoracic radiotherapy. The patients were stratified by cell type, extent of operation, age, sex, and status of supraclavicular lymph nodes. All patients were followed until death or for a minimum of 4.8 years. Of the 102 evaluable patients, 98 were treated with either 4-MV or 10-MV photons (49 patients in each group). Outcomes examined included best primary tumor response, time to first local (in-field) recurrence, disease-free survival, and overall survival. No significant differences were detected between the patients treated with 4-MV or 10-MV photons for several important prognostic and treatment factors or for any of the study outcomes, including first local (in-field) recurrence, disease-free survival, and overall survival. For the group of 98 patients treated with either 4-MV or 10-MV photons, the estimated 2-year freedom from first local (in-field) recurrence was 47.7%. The estimated 2-year disease-free and overall survivals were 21.6% and 28.6%, respectively.

The effect of hyperfractionation on spinal cord response to radiation

The T10-L2 level of the spinal cord of C3Hf mice was irradiated using a conventionally fractionated regimen of 2.0 Gy once daily or a hyperfractionated regimen of 1.2 Gy twice daily separated by 8 hr. After a fractionated dose of 24-60 Gy given by either regimen, a top-up dose of 15 Gy was given. Hind limb strength was then measured weekly for 15 months. The time to onset of paralysis was inversely associated with the total dose. Overall, the spinal cord was not spared by hyperfractionation to the extent predicted by the modified Ellis power law or the linear-quadratic model. The threshold dose for the development of paralysis was higher in the hyperfractionated than in the conventionally fractionated group. However, the latent period for paralysis and the dose producing hind limb paralysis in 50% of the mice (ED50) were not significantly different between the two regimens. The continuation of the process of sublethal damage (SLD) repair in the spinal cord beyond 8 hr after irradiation may have influenced these results. The slow component of SLD repair should be considered in the design of hyperfractionated or accelerated radiation therapy schedules for clinical use.

Prophylactic cranial irradiation for lung cancer patients at high risk for development of cerebral metastasis: results of a prospective randomized trial conducted by the Radiation Therapy Oncology Group

Beginning in February 1984, 187 evaluable patients with adenocarcinoma or large cell carcinoma of the lung clinically confined to the chest were randomized to receive either conventionally fractionated thoracic irradiation alone or thoracic irradiation with concurrent, prophylactic cranial irradiation. The study population included 161 patients treated for medically or surgically inoperable primary cancers, and 26 patients undergoing adjuvant postoperative mediastinal irradiation following attempted curative resection of primary cancers found to have metastasized to hilar or mediastinal lymph nodes. Elective brain irradiation was not effective in preventing the clinical appearance of brain metastases, although the time to develop brain metastases appears to have been delayed. Eighteen of 94 patients (19%) randomized to chest irradiation alone have developed brain metastases as opposed to 8/93 patients (9%) randomized to receive prophylactic cranial irradiation (p = .10). No survival difference was observed between the treatment arms. Among the 26 patients undergoing prior resection of all gross intrathoracic disease, brain metastases were observed in 3/12 patients (25%) receiving adjuvant chest irradiation alone, compared to none of 14 receiving prophylactic cranial irradiation (p = .06). In the absence of fully reliable therapy for the primary disease, and without effective systemic therapy preventing dissemination to other, extrathoracic sites, prophylactic cranial irradiation for inoperable non-small cell lung cancer cannot be justified in routine clinical practice. Further investigation in the adjuvant, postoperative setting may be warranted.

Comparison of the Radiation Therapy Oncology Group and American Joint Committee on Cancer staging systems among patients with non-small cell lung cancer receiving hyperfractionated radiation therapy. A report of the Radiation Therapy Oncology Group protocol 83-11

Since 1973, the Radiation Therapy Oncology Group (RTOG) has staged and stratified patients in non-small cell lung cancer (NSCLC) protocols according to the RTOG staging system. In 1985, the American Joint Committee on Cancer (AJCC) revised its lung cancer staging system, with the principle differences from the RTOG system being the staging of involvement of the chest wall and of contralateral mediastinal and hilar lymph nodes. To determine if the AJCC system discriminated outcome differently than the RTOG system in a nonoperative series, all 850 evaluable patients treated with hyperfractionated radiation therapy (RT) on the RTOG protocol 83-11 were restaged by the AJCC system. There was 67% agreement in patient distribution between the following comparable stages in each system: RTOG Stage II/AJCC Stage II; RTOG Stage III/AJCC Stage IIIA; and RTOG Stage IV/AJCC Stage IIIB. Both systems successfully predicted for survival (P less than 0.001), although the RTOG staging was more discriminating (relative risk ratios, 1.59 versus 1.38). Among the 507 favorable patients (those with less than or equal to 5% weight loss and Karnofsky performance status [KPS] of 70 to 100), the RTOG staging was also more predictive (P = 0.004 versus P = 0.01). When RTOG Stage III (462 patients) was divided into those without contralateral mediastinal or hilar adenopathy (AJCC Stage II/IIIA) and those with (AJCC Stage IIIB), a significant survival (P = 0.0001) was noted with 2-year survival rates of 26% versus 4%, respectively. When AJCC Stage IIIA (348 patients) was divided into the patients without chest wall invasion (RTOG Stage II/III) and those with (RTOG Stage IV), a difference in 2-year survival of 22% versus 10% was observed (P = 0.002). Although both staging systems independently predict for survival, a fusion of both staging systems is the most discriminating of outcome. Future nonoperative studies in locally advanced NSCLC should stratify for contralateral nodal involvement (per AJCC staging) and chest wall invasion (per RTOG staging).

Rapidly alternating radiotherapy and high dose cisplatin chemotherapy in stage IIIB non-small cell lung cancer: results of a phase I/II study

Alternating radiotherapy and chemotherapy increases tumor cure rates in some animal models with reduced normal tissue damage compared to sequential use of these modalities. To test this concept in non-small cell lung cancer, 23 patients with predominantly Stage IIIB disease were treated on a Northern California Oncology Group pilot study of alternating radiotherapy and high dose cisplatin. Radiotherapy consisted of 6000 cGy delivered in three separate 10-day courses of 200 cGy/fraction/day during weeks 1 and 2, 5 and 6, and 9 and 10. High dose cisplatin, 100 mg/m2 in 3% saline, was administered on weeks 3 and 4, 7 and 8, 11 and 12, and 15 and 16. The response rate in 22 eligible patients is 73% (16/22) with four complete responses and 12 partial responses. Feasibility of this approach is demonstrated by 20/22 patients completing radiotherapy and a median of 2.5 courses of chemotherapy administered. Median survival time is 14.2 months (range 2-40+ months). One- and 2-year survival rates are 64% (14/22) and 41% (9/22), respectively. Hematologic, renal, and radiation-related toxicities were significant but manageable. We conclude that rapid alternation of radiotherapy and a high dose intensity cisplatin regimen is feasible in Stage IIIB non-small cell lung cancer, with a high response rate and acceptable toxicity. The long-term impact on local control and survival remains unclear, although preliminary survival data are encouraging in this poor prognosis population. Further studies of this concept are warranted.

N2 (clinical) non-small cell carcinoma of the lung: prospective trials of radiation therapy with total doses 60 Gy by the Radiation Therapy Oncology Group

Clinical Stage III (N2) non-small cell carcinoma of the lung encompasses a large group of patients, frequently treated with radiation therapy alone, who are now considered to have borderline-resectable tumors. Pilot studies are proceeding which use combinations of resection, radiation therapy, and chemotherapy. To place trials of combination therapy in perspective with contemporary results of radiation therapy alone, recently completed trials of the RTOG were analyzed specifically for clinical Stages T1-3N2. A prospective randomized trial of hyperfractionated radiation therapy (HFX), conducted from 1983 through 1987, compared total doses of 60.0, 64.8, and 69.6 Gy using 1.2 Gy bid with greater than or equal to 4 hr interval. After acute and late effects were considered tolerable, 74.4 Gy and 79.2 Gy arms supplanted the two lowest dose arms. Survival was compared among the five total dose arms, and with 60 Gy in 30 fractions in 6 weeks (standard fractionation-STD) from earlier RTOG studies. Of 516 HFX patients analyzed, 296 (57.3%) with Performance Status (PS) 70-100 and less than 5% weight loss (favorable) had a significantly (p = .001) better survival than those with PS 50-69 or weight loss greater than 5%. Patients with RTOG Stage III (361, 70.0%) experienced better survival (p = .027) than RTOG Stage IV M0. The 69.6 Gy total dose arm was significantly (p = .031) better in favorable RTOG Stage III patients than all other total dose arms: the 1-year survival rate was 58% and the 3-year rate was 20%. The 69.6 Gy HFX results were significantly (p = .002) better than results with STD fractionation in comparable patients from earlier RTOG trials (1-year survival = 30%, 3-year survival = 7%). A prospective, randomized Phase III comparison of STD with 60 Gy versus HFX with 69.6 Gy is underway. These results provide benchmarks for studies of surgical resection combined with chemotherapy and/or radiation therapy until results of prospective comparisons with concurrent controls are available.

Role of brachytherapy in the management of pulmonary and mediastinal malignancies

Brachytherapy, the permanent or temporary implantation of radioactive sources, has been performed in limited numbers of patients with lung cancer over the last 50 years. Because of renewed interest in this modality, we reviewed our experience with 103 patients treated over a 7-year period. The mean age of this group was 55.5 years (range, 1 to 84 years). Primary lung cancer accounted for 82 patients (79.6%); metastatic lesions to the lung, 13 (12.6%); and mediastinal malignancies, 8 (7.8%). Indications for brachytherapy included mediastinal and chest wall invasion in 42 patients (40.8%), unresectable tumors and mediastinal adenopathy in 30 (29.1%), medical contraindications to extensive pulmonary resection in 20 (19.4%), and irradiation of excised lymph node beds in 11 (10.7%). Seeds labeled with radioactive iodine 125 alone were used in 65 patients (63.1%), afterloading catheters containing iridium 192 sources in 25 (24.3%), and both in 13 (12.6%). There were no operative deaths. With a mean follow-up of 18.6 months, the mean and median survivals for the entire group were 17.3 and 14.0 months, respectively. The 1-year, 2-year, and 3-year survivals for the entire group were 67.9%, 38.7%, and 27.8%, respectively. In summary, brachytherapy offers a useful surgical approach in patients in whom unresectable pulmonary or mediastinal malignancies are found at the time of thoracotomy or in patients previously treated with other modalities for whom limited therapeutic alternatives exist.

Radiotherapy of the rhabdomyosarcoma R1H of the rat: hyperfractionation--126 fractions applied within 6 weeks

The effect of a hyperfractionated irradiation treatment on the response of the rhabdomyosarcoma R1H of the rat was studied. Tumors were irradiated under ambient conditions with 126 fractions of X rays, applied in 3 fractions per day with a time interval of 8 +/- 1 hr between fractions on 7 days per week during 6 weeks. The total dose ranged from 54 to 90 Gy, that is the dose per fraction ranged from 0.43 to 0.71 Gy. Tumor response was assessed by tumor control probability and tumor net growth delay. The tumor response to the hyperfractionated treatment was found to be slightly more effective compared to the results obtained in a previous study where treatments with 6, 18, 30, and 42 fractions were applied. Since normal tissues are considerably spared with increased numbers of fractions, clinical studies with hyperfractionation seem to be very promising.

Lung cancer in Australia

Lung cancer is the leading cause of death of cancer in Australian men and the third leading cause in Australian women. Efforts are being made to reduce the incidence of this disease by smoking-cessation programmes and improved industrial hygiene, and these measures need to be encouraged strongly by all sectors of the community. On a population basis, insufficient evidence is available to justify screening procedures for the early detection of lung cancer in "at-risk" groups. Cure is possible by surgical resection in early cases. Improvements in therapeutic results with traditional cancer treatments largely have reached a plateau, but a number of newer therapies, and combinations of standard therapies, currently are being evaluated. Of particular interest is concurrent radiotherapy and chemotherapy in localized non-small-cell lung cancer; laser "debulking" in conjunction with radiotherapy in non-small-cell lung cancer, and biological response-modifying agents in non-small-cell and small-cell lung cancer. It is important that data be collected adequately to define epidemiological changes and to evaluate treatment results (including repeat bronchoscopy, to assess local control of tumour), and that the quality of life is recorded and reported in the evaluation process. Finally, phase-III studies in lung-cancer treatments require adequate numbers of subjects to enable meaningful conclusions to be achieve objectives within a reasonable study period.

Radiotherapy of the rhabdomyosarcoma R1H of the rat: the influence of the number of fractions on tumor and skin response

The influence of the number of fractions on tumor and skin response to fractionated irradiation was studied. R1H rhabdomyosarcomas of the rat (volume doubling time 3 days) were irradiated with 6, 18, 30, or 42 fractions in 6 weeks. Total doses of 45, 60, or 75 Gy were applied in each fractionation scheme, that is, the dose per fraction ranged from 1.07 to 12.5 Gy. Tumor response was assessed by tumor control probability and tumor net growth delay. A clearcut reduction of skin damage was observed with increasing number of fractions, whereas the tumor response was found to be the same whether the dose was given in 6, 18, 30, or 42 fractions. Thus, the fractionation regimens were more effective than expected from calculations based on single-dose in situ survival curves. This result can be explained by assuming that the clonogenic tumor cells become less hypoxic with increasing number of fractions. Since normal tissue damage decreases with increasing number of fractions, the therapeutic gain may be improved by applying a greater number of fractions.

The role of external radiation and brachytherapy in unresectable non-small cell lung cancer

The role of radiation therapy in the management of non-small cell lung cancer is rapidly changing. Preoperative radiation, with the exception of the superior sulcus tumor, has not been found to benefit patients. The issue of postoperative radiation in completely resected patients with non-small cell lung cancer remains controversial. Current postoperative trials suggest, however, that postoperative radiation in these patients prevents local recurrence and, in combination with chemotherapy, prolongs survival. Primary radiation therapy in inoperable non-small cell lung cancer is associated with a small but definite cure rate. Better definition of treatment volume, proper selection of dose-time, state-of-art treatment planning, and, whenever possible, intraoperative radiation have improved local control rates and decreased severe complications.

Large fraction irradiation with or without misonidazole in advanced non-oat cell carcinoma of the lung: a phase III randomized trial of the RTOG. Radiation Therapy Oncology Group

The Radiation Therapy Oncology Group (RTOG) investigated the use of misonidazole as an hypoxic cell sensitizer in a Phase III prospective randomized trial employing radiotherapy, 600 cGy twice weekly to a total of 3600 cGy with and without misonidazole in the treatment of locally advanced non-metastatic squamous cell, adeno, or large cell carcinoma of the lung. Between January 1980 and July 1983, 117 patients from 21 institutions were enrolled. One-hundred eight patients were evaluable; 53 in the combined treatment arm and 55 in the radiation alone arm. Grade 3 or worse complications associated with radiation occurred in 17% of patients. Esophageal toxicity accounted for the majority of complications. Two (4%) patients in the radiotherapy plus misonidazole group experienced grade 3 peripheral neurotoxicity. Complete or partial responses were produced in 58% of the patients with radiotherapy alone and 36% of those treated with radiotherapy plus misonidazole (p = 0.08). At the time of first progression, over 50% of the patients had persistent local disease. Median survival was 7 months regardless of treatment. Misonidazole in the dose and schedule employed did not enhance the effect of radiotherapy on either local tumor control or overall survival in patients with advanced lung cancer.